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| <a href="#libvips-meta.synopsis" class="shortcut">Top</a> |
| | |
| <a href="#libvips-meta.description" class="shortcut">Description</a> |
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| <div class="refentry" title="meta"> |
| <a name="libvips-meta"></a><div class="titlepage"></div> |
| <div class="refnamediv"><table width="100%"><tr> |
| <td valign="top"> |
| <h2><span class="refentrytitle"><a name="libvips-meta.top_of_page"></a>meta</span></h2> |
| <p>meta — get and set image metadata</p> |
| </td> |
| <td valign="top" align="right"></td> |
| </tr></table></div> |
| <div class="refsect1" title="Stability Level"> |
| <a name="libvips-meta.stability-level"></a><h2>Stability Level</h2> |
| Stable, unless otherwise indicated |
| </div> |
| <div class="refsynopsisdiv" title="Synopsis"> |
| <a name="libvips-meta.synopsis"></a><h2>Synopsis</h2> |
| <pre class="synopsis"> |
| #include <vips/vips.h> |
| |
| #define <a class="link" href="libvips-meta.html#IM-META-EXIF-NAME:CAPS" title="IM_META_EXIF_NAME">IM_META_EXIF_NAME</a> |
| #define <a class="link" href="libvips-meta.html#IM-META-ICC-NAME:CAPS" title="IM_META_ICC_NAME">IM_META_ICC_NAME</a> |
| #define <a class="link" href="libvips-meta.html#IM-META-XML:CAPS" title="IM_META_XML">IM_META_XML</a> |
| #define <a class="link" href="libvips-meta.html#IM-META-RESOLUTION-UNIT:CAPS" title="IM_META_RESOLUTION_UNIT">IM_META_RESOLUTION_UNIT</a> |
| #define <a class="link" href="libvips-meta.html#IM-TYPE-SAVE-STRING:CAPS" title="IM_TYPE_SAVE_STRING">IM_TYPE_SAVE_STRING</a> |
| <span class="returnvalue">GType</span> <a class="link" href="libvips-meta.html#im-save-string-get-type" title="im_save_string_get_type ()">im_save_string_get_type</a> (<em class="parameter"><code><span class="type">void</span></code></em>); |
| const <span class="returnvalue">char</span> * <a class="link" href="libvips-meta.html#im-save-string-get" title="im_save_string_get ()">im_save_string_get</a> (<em class="parameter"><code>const <span class="type">GValue</span> *value</code></em>); |
| <span class="returnvalue">void</span> <a class="link" href="libvips-meta.html#im-save-string-set" title="im_save_string_set ()">im_save_string_set</a> (<em class="parameter"><code><span class="type">GValue</span> *value</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *str</code></em>); |
| <span class="returnvalue">void</span> <a class="link" href="libvips-meta.html#im-save-string-setf" title="im_save_string_setf ()">im_save_string_setf</a> (<em class="parameter"><code><span class="type">GValue</span> *value</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *fmt</code></em>, |
| <em class="parameter"><code>...</code></em>); |
| #define <a class="link" href="libvips-meta.html#IM-TYPE-AREA:CAPS" title="IM_TYPE_AREA">IM_TYPE_AREA</a> |
| <span class="returnvalue">GType</span> <a class="link" href="libvips-meta.html#im-area-get-type" title="im_area_get_type ()">im_area_get_type</a> (<em class="parameter"><code><span class="type">void</span></code></em>); |
| #define <a class="link" href="libvips-meta.html#IM-TYPE-REF-STRING:CAPS" title="IM_TYPE_REF_STRING">IM_TYPE_REF_STRING</a> |
| <span class="returnvalue">GType</span> <a class="link" href="libvips-meta.html#im-ref-string-get-type" title="im_ref_string_get_type ()">im_ref_string_get_type</a> (<em class="parameter"><code><span class="type">void</span></code></em>); |
| <span class="returnvalue">int</span> <a class="link" href="libvips-meta.html#im-ref-string-set" title="im_ref_string_set ()">im_ref_string_set</a> (<em class="parameter"><code><span class="type">GValue</span> *value</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *str</code></em>); |
| const <span class="returnvalue">char</span> * <a class="link" href="libvips-meta.html#im-ref-string-get" title="im_ref_string_get ()">im_ref_string_get</a> (<em class="parameter"><code>const <span class="type">GValue</span> *value</code></em>); |
| <span class="returnvalue">size_t</span> <a class="link" href="libvips-meta.html#im-ref-string-get-length" title="im_ref_string_get_length ()">im_ref_string_get_length</a> (<em class="parameter"><code>const <span class="type">GValue</span> *value</code></em>); |
| #define <a class="link" href="libvips-meta.html#IM-TYPE-BLOB:CAPS" title="IM_TYPE_BLOB">IM_TYPE_BLOB</a> |
| <span class="returnvalue">GType</span> <a class="link" href="libvips-meta.html#im-blob-get-type" title="im_blob_get_type ()">im_blob_get_type</a> (<em class="parameter"><code><span class="type">void</span></code></em>); |
| <span class="returnvalue">void</span> * <a class="link" href="libvips-meta.html#im-blob-get" title="im_blob_get ()">im_blob_get</a> (<em class="parameter"><code>const <span class="type">GValue</span> *value</code></em>, |
| <em class="parameter"><code><span class="type">size_t</span> *data_length</code></em>); |
| <span class="returnvalue">int</span> <a class="link" href="libvips-meta.html#im-blob-set" title="im_blob_set ()">im_blob_set</a> (<em class="parameter"><code><span class="type">GValue</span> *value</code></em>, |
| <em class="parameter"><code><a class="link" href="libvips-callback.html#im-callback-fn" title="im_callback_fn ()"><span class="type">im_callback_fn</span></a> free_fn</code></em>, |
| <em class="parameter"><code><span class="type">void</span> *data</code></em>, |
| <em class="parameter"><code><span class="type">size_t</span> length</code></em>); |
| <span class="returnvalue">int</span> <a class="link" href="libvips-meta.html#im-meta-set" title="im_meta_set ()">im_meta_set</a> (<em class="parameter"><code><span class="type">IMAGE</span> *Param1</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>, |
| <em class="parameter"><code><span class="type">GValue</span> *Param3</code></em>); |
| <span class="returnvalue">gboolean</span> <a class="link" href="libvips-meta.html#im-meta-remove" title="im_meta_remove ()">im_meta_remove</a> (<em class="parameter"><code><span class="type">IMAGE</span> *im</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>); |
| <span class="returnvalue">int</span> <a class="link" href="libvips-meta.html#im-meta-get" title="im_meta_get ()">im_meta_get</a> (<em class="parameter"><code><span class="type">IMAGE</span> *Param1</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>, |
| <em class="parameter"><code><span class="type">GValue</span> *Param3</code></em>); |
| <span class="returnvalue">GType</span> <a class="link" href="libvips-meta.html#im-meta-get-typeof" title="im_meta_get_typeof ()">im_meta_get_typeof</a> (<em class="parameter"><code><span class="type">IMAGE</span> *im</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>); |
| <span class="returnvalue">int</span> <a class="link" href="libvips-meta.html#im-meta-set-int" title="im_meta_set_int ()">im_meta_set_int</a> (<em class="parameter"><code><span class="type">IMAGE</span> *Param1</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>, |
| <em class="parameter"><code><span class="type">int</span> i</code></em>); |
| <span class="returnvalue">int</span> <a class="link" href="libvips-meta.html#im-meta-get-int" title="im_meta_get_int ()">im_meta_get_int</a> (<em class="parameter"><code><span class="type">IMAGE</span> *Param1</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>, |
| <em class="parameter"><code><span class="type">int</span> *i</code></em>); |
| <span class="returnvalue">int</span> <a class="link" href="libvips-meta.html#im-meta-set-double" title="im_meta_set_double ()">im_meta_set_double</a> (<em class="parameter"><code><span class="type">IMAGE</span> *Param1</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>, |
| <em class="parameter"><code><span class="type">double</span> d</code></em>); |
| <span class="returnvalue">int</span> <a class="link" href="libvips-meta.html#im-meta-get-double" title="im_meta_get_double ()">im_meta_get_double</a> (<em class="parameter"><code><span class="type">IMAGE</span> *Param1</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>, |
| <em class="parameter"><code><span class="type">double</span> *d</code></em>); |
| <span class="returnvalue">int</span> <a class="link" href="libvips-meta.html#im-meta-set-area" title="im_meta_set_area ()">im_meta_set_area</a> (<em class="parameter"><code><span class="type">IMAGE</span> *Param1</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>, |
| <em class="parameter"><code><a class="link" href="libvips-callback.html#im-callback-fn" title="im_callback_fn ()"><span class="type">im_callback_fn</span></a> Param3</code></em>, |
| <em class="parameter"><code><span class="type">void</span> *Param4</code></em>); |
| <span class="returnvalue">int</span> <a class="link" href="libvips-meta.html#im-meta-get-area" title="im_meta_get_area ()">im_meta_get_area</a> (<em class="parameter"><code><span class="type">IMAGE</span> *Param1</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>, |
| <em class="parameter"><code><span class="type">void</span> **data</code></em>); |
| <span class="returnvalue">int</span> <a class="link" href="libvips-meta.html#im-meta-set-string" title="im_meta_set_string ()">im_meta_set_string</a> (<em class="parameter"><code><span class="type">IMAGE</span> *Param1</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *str</code></em>); |
| <span class="returnvalue">int</span> <a class="link" href="libvips-meta.html#im-meta-get-string" title="im_meta_get_string ()">im_meta_get_string</a> (<em class="parameter"><code><span class="type">IMAGE</span> *Param1</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>, |
| <em class="parameter"><code><span class="type">char</span> **str</code></em>); |
| <span class="returnvalue">int</span> <a class="link" href="libvips-meta.html#im-meta-set-blob" title="im_meta_set_blob ()">im_meta_set_blob</a> (<em class="parameter"><code><span class="type">IMAGE</span> *im</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>, |
| <em class="parameter"><code><a class="link" href="libvips-callback.html#im-callback-fn" title="im_callback_fn ()"><span class="type">im_callback_fn</span></a> free_fn</code></em>, |
| <em class="parameter"><code><span class="type">void</span> *blob</code></em>, |
| <em class="parameter"><code><span class="type">size_t</span> blob_length</code></em>); |
| <span class="returnvalue">int</span> <a class="link" href="libvips-meta.html#im-meta-get-blob" title="im_meta_get_blob ()">im_meta_get_blob</a> (<em class="parameter"><code><span class="type">IMAGE</span> *im</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>, |
| <em class="parameter"><code><span class="type">void</span> **blob</code></em>, |
| <em class="parameter"><code><span class="type">size_t</span> *blob_length</code></em>); |
| </pre> |
| </div> |
| <div class="refsect1" title="Description"> |
| <a name="libvips-meta.description"></a><h2>Description</h2> |
| <p> |
| You can attach arbitrary metadata to images. Metadata is copied as images |
| are processed, so all images which used this image as input, directly or |
| indirectly, will have this same bit of metadata attached to them. Copying |
| is implemented with reference-counted pointers, so it is efficient, even for |
| large items of data. This does however mean that metadata items need to be |
| immutable. Metadata |
| is handy for things like ICC profiles or EXIF data. |
| </p> |
| <p> |
| Various convenience functions (eg. <a class="link" href="libvips-meta.html#im-meta-set-int" title="im_meta_set_int ()"><code class="function">im_meta_set_int()</code></a>) let you easily attach |
| simple types like |
| numbers, strings and memory blocks to images. Use <a class="link" href="libvips-header.html#im-header-map" title="im_header_map ()"><code class="function">im_header_map()</code></a> to loop |
| over an image's fields, including all metadata. |
| </p> |
| <p> |
| Items of metadata are identified by strings. Some strings are reserved, for |
| example the ICC pofile for an image is known by convention as |
| "icc-profile-data". |
| </p> |
| <p> |
| If you save an image in VIPS format, all metadata (with a restriction, see |
| below) is automatically saved for you in a block of XML at the end of the |
| file. When you load a VIPS image, the metadata is restored. You can use the |
| 'edvips' command-line tool to extract or replace this block of XML. |
| </p> |
| <p> |
| VIPS metadata is based on GValue. See the docs for that system if you want |
| to do fancy stuff such as defining a new metadata type. |
| VIPS defines a new GValue called "im_save_string", a variety of string. If |
| your GValue can be transformed to im_save_string, it will be saved and |
| loaded to and from VIPS files for you. |
| </p> |
| <p> |
| VIPS provides a couple of base classes which implement |
| reference-counted areas of memory. If you base your metadata on one of |
| these types, it can be copied between images efficiently. |
| </p> |
| </div> |
| <div class="refsect1" title="Details"> |
| <a name="libvips-meta.details"></a><h2>Details</h2> |
| <div class="refsect2" title="IM_META_EXIF_NAME"> |
| <a name="IM-META-EXIF-NAME:CAPS"></a><h3>IM_META_EXIF_NAME</h3> |
| <pre class="programlisting">#define IM_META_EXIF_NAME "exif-data" |
| </pre> |
| <p> |
| The name that JPEG read and write operations use for the image's EXIF data. |
| </p> |
| </div> |
| <hr> |
| <div class="refsect2" title="IM_META_ICC_NAME"> |
| <a name="IM-META-ICC-NAME:CAPS"></a><h3>IM_META_ICC_NAME</h3> |
| <pre class="programlisting">#define IM_META_ICC_NAME "icc-profile-data" |
| </pre> |
| <p> |
| The name we use to attach an ICC profile. The file read and write |
| operations for TIFF, JPEG, PNG and others use this item of metadata to |
| attach and save ICC profiles. The profile is updated by the |
| <a class="link" href="libvips-colour.html#im-icc-transform" title="im_icc_transform ()"><code class="function">im_icc_transform()</code></a> operations. |
| </p> |
| </div> |
| <hr> |
| <div class="refsect2" title="IM_META_XML"> |
| <a name="IM-META-XML:CAPS"></a><h3>IM_META_XML</h3> |
| <pre class="programlisting">#define IM_META_XML "xml-header" |
| </pre> |
| <p> |
| The original XML that was used to code the metadata after reading a VIPS |
| format file. |
| </p> |
| </div> |
| <hr> |
| <div class="refsect2" title="IM_META_RESOLUTION_UNIT"> |
| <a name="IM-META-RESOLUTION-UNIT:CAPS"></a><h3>IM_META_RESOLUTION_UNIT</h3> |
| <pre class="programlisting">#define IM_META_RESOLUTION_UNIT "resolution-unit" |
| </pre> |
| <p> |
| The JPEG and TIFF read and write operations use this to record the |
| file's preferred unit for resolution. |
| </p> |
| </div> |
| <hr> |
| <div class="refsect2" title="IM_TYPE_SAVE_STRING"> |
| <a name="IM-TYPE-SAVE-STRING:CAPS"></a><h3>IM_TYPE_SAVE_STRING</h3> |
| <pre class="programlisting">#define IM_TYPE_SAVE_STRING (im_save_string_get_type()) |
| </pre> |
| <p> |
| The <span class="type">GType</span> for an "im_save_string". |
| </p> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_save_string_get_type ()"> |
| <a name="im-save-string-get-type"></a><h3>im_save_string_get_type ()</h3> |
| <pre class="programlisting"><span class="returnvalue">GType</span> im_save_string_get_type (<em class="parameter"><code><span class="type">void</span></code></em>);</pre> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_save_string_get ()"> |
| <a name="im-save-string-get"></a><h3>im_save_string_get ()</h3> |
| <pre class="programlisting">const <span class="returnvalue">char</span> * im_save_string_get (<em class="parameter"><code>const <span class="type">GValue</span> *value</code></em>);</pre> |
| <p> |
| Get the C string held internally by the GValue. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>value</code></em> :</span></p></td> |
| <td>GValue to get from |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> The C string held by <em class="parameter"><code>value</code></em>. This must not be freed. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_save_string_set ()"> |
| <a name="im-save-string-set"></a><h3>im_save_string_set ()</h3> |
| <pre class="programlisting"><span class="returnvalue">void</span> im_save_string_set (<em class="parameter"><code><span class="type">GValue</span> *value</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *str</code></em>);</pre> |
| <p> |
| Copies the C string into <em class="parameter"><code>value</code></em>. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>value</code></em> :</span></p></td> |
| <td>GValue to set |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>str</code></em> :</span></p></td> |
| <td>C string to copy into the GValue |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_save_string_setf ()"> |
| <a name="im-save-string-setf"></a><h3>im_save_string_setf ()</h3> |
| <pre class="programlisting"><span class="returnvalue">void</span> im_save_string_setf (<em class="parameter"><code><span class="type">GValue</span> *value</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *fmt</code></em>, |
| <em class="parameter"><code>...</code></em>);</pre> |
| <p> |
| Generates a string and copies it into <em class="parameter"><code>value</code></em>. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>value</code></em> :</span></p></td> |
| <td>GValue to set |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>fmt</code></em> :</span></p></td> |
| <td>printf()-style format string |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>...</code></em> :</span></p></td> |
| <td>arguments to <code class="function">printf()</code>-formatted <em class="parameter"><code>fmt</code></em> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="IM_TYPE_AREA"> |
| <a name="IM-TYPE-AREA:CAPS"></a><h3>IM_TYPE_AREA</h3> |
| <pre class="programlisting">#define IM_TYPE_AREA (im_area_get_type()) |
| </pre> |
| <p> |
| The <span class="type">GType</span> for an <span class="type">im_area</span>. |
| </p> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_area_get_type ()"> |
| <a name="im-area-get-type"></a><h3>im_area_get_type ()</h3> |
| <pre class="programlisting"><span class="returnvalue">GType</span> im_area_get_type (<em class="parameter"><code><span class="type">void</span></code></em>);</pre> |
| </div> |
| <hr> |
| <div class="refsect2" title="IM_TYPE_REF_STRING"> |
| <a name="IM-TYPE-REF-STRING:CAPS"></a><h3>IM_TYPE_REF_STRING</h3> |
| <pre class="programlisting">#define IM_TYPE_REF_STRING (im_ref_string_get_type()) |
| </pre> |
| <p> |
| The <span class="type">GType</span> for an <span class="type">im_refstring</span>. |
| </p> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_ref_string_get_type ()"> |
| <a name="im-ref-string-get-type"></a><h3>im_ref_string_get_type ()</h3> |
| <pre class="programlisting"><span class="returnvalue">GType</span> im_ref_string_get_type (<em class="parameter"><code><span class="type">void</span></code></em>);</pre> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_ref_string_set ()"> |
| <a name="im-ref-string-set"></a><h3>im_ref_string_set ()</h3> |
| <pre class="programlisting"><span class="returnvalue">int</span> im_ref_string_set (<em class="parameter"><code><span class="type">GValue</span> *value</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *str</code></em>);</pre> |
| <p> |
| Copies the C string <em class="parameter"><code>str</code></em> into <em class="parameter"><code>value</code></em>. |
| </p> |
| <p> |
| im_ref_string are immutable C strings that are copied between images by |
| copying reference-counted pointers, making the much more efficient than |
| regular GValue strings. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>value</code></em> :</span></p></td> |
| <td>GValue to set |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>str</code></em> :</span></p></td> |
| <td>C string to copy into the GValue |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> 0 on success, -1 otherwise. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_ref_string_get ()"> |
| <a name="im-ref-string-get"></a><h3>im_ref_string_get ()</h3> |
| <pre class="programlisting">const <span class="returnvalue">char</span> * im_ref_string_get (<em class="parameter"><code>const <span class="type">GValue</span> *value</code></em>);</pre> |
| <p> |
| Get the C string held internally by the GValue. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>value</code></em> :</span></p></td> |
| <td>GValue to get from |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> The C string held by <em class="parameter"><code>value</code></em>. This must not be freed. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_ref_string_get_length ()"> |
| <a name="im-ref-string-get-length"></a><h3>im_ref_string_get_length ()</h3> |
| <pre class="programlisting"><span class="returnvalue">size_t</span> im_ref_string_get_length (<em class="parameter"><code>const <span class="type">GValue</span> *value</code></em>);</pre> |
| <p> |
| Gets the cached string length held internally by the refstring. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>value</code></em> :</span></p></td> |
| <td>GValue to get from |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> The length of the string. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="IM_TYPE_BLOB"> |
| <a name="IM-TYPE-BLOB:CAPS"></a><h3>IM_TYPE_BLOB</h3> |
| <pre class="programlisting">#define IM_TYPE_BLOB (im_blob_get_type()) |
| </pre> |
| <p> |
| The <span class="type">GType</span> for an <span class="type">im_blob</span>. |
| </p> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_blob_get_type ()"> |
| <a name="im-blob-get-type"></a><h3>im_blob_get_type ()</h3> |
| <pre class="programlisting"><span class="returnvalue">GType</span> im_blob_get_type (<em class="parameter"><code><span class="type">void</span></code></em>);</pre> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_blob_get ()"> |
| <a name="im-blob-get"></a><h3>im_blob_get ()</h3> |
| <pre class="programlisting"><span class="returnvalue">void</span> * im_blob_get (<em class="parameter"><code>const <span class="type">GValue</span> *value</code></em>, |
| <em class="parameter"><code><span class="type">size_t</span> *data_length</code></em>);</pre> |
| <p> |
| Get the address of the blob (binary large object) being held in <em class="parameter"><code>value</code></em> and |
| optionally return its length in <em class="parameter"><code>blob_length</code></em>. |
| </p> |
| <p> |
| See also: <a class="link" href="libvips-meta.html#im-blob-set" title="im_blob_set ()"><code class="function">im_blob_set()</code></a> |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>value</code></em> :</span></p></td> |
| <td>GValue to get from |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>blob_length</code></em> :</span></p></td> |
| <td>return the blob length here, optionally |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> The blob address. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_blob_set ()"> |
| <a name="im-blob-set"></a><h3>im_blob_set ()</h3> |
| <pre class="programlisting"><span class="returnvalue">int</span> im_blob_set (<em class="parameter"><code><span class="type">GValue</span> *value</code></em>, |
| <em class="parameter"><code><a class="link" href="libvips-callback.html#im-callback-fn" title="im_callback_fn ()"><span class="type">im_callback_fn</span></a> free_fn</code></em>, |
| <em class="parameter"><code><span class="type">void</span> *data</code></em>, |
| <em class="parameter"><code><span class="type">size_t</span> length</code></em>);</pre> |
| <p> |
| Sets <em class="parameter"><code>value</code></em> to hold a pointer to <em class="parameter"><code>blob</code></em>. When <em class="parameter"><code>value</code></em> is freed, <em class="parameter"><code>blob</code></em> will be |
| freed with <em class="parameter"><code>free_fn</code></em>. <em class="parameter"><code>value</code></em> also holds a note of the length of the memory |
| area. |
| </p> |
| <p> |
| blobs are things like ICC profiles or EXIF data. They are relocatable, and |
| are saved to VIPS files for you coded as base64 inside the XML. They are |
| copied by copying reference-counted pointers. |
| </p> |
| <p> |
| See also: <a class="link" href="libvips-meta.html#im-blob-get" title="im_blob_get ()"><code class="function">im_blob_get()</code></a> |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>value</code></em> :</span></p></td> |
| <td>GValue to set |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>free_fn</code></em> :</span></p></td> |
| <td>free function for <em class="parameter"><code>data</code></em> |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>blob</code></em> :</span></p></td> |
| <td>pointer to area of memory |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>blob_length</code></em> :</span></p></td> |
| <td>length of memory area |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> 0 on success, -1 otherwise. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_meta_set ()"> |
| <a name="im-meta-set"></a><h3>im_meta_set ()</h3> |
| <pre class="programlisting"><span class="returnvalue">int</span> im_meta_set (<em class="parameter"><code><span class="type">IMAGE</span> *Param1</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>, |
| <em class="parameter"><code><span class="type">GValue</span> *Param3</code></em>);</pre> |
| <p> |
| Set a piece of metadata on <em class="parameter"><code>im</code></em>. Any old metadata with that name is |
| destroyed. The GValue is copied into the image, so you need to unset the |
| value when you're done with it. |
| </p> |
| <p> |
| For example, to set an integer on an image (though you would use the |
| convenience function <a class="link" href="libvips-meta.html#im-meta-set-int" title="im_meta_set_int ()"><code class="function">im_meta_set_int()</code></a> in practice), you would need: |
| </p> |
| <p> |
| </p> |
| <div class="informalexample"><pre class="programlisting"> |
| GValue value = { 0 }; |
| |
| g_value_init( &value, G_TYPE_INT ); |
| g_value_set_int( &value, 42 ); |
| |
| if( im_meta_set( im, field, &value ) ) { |
| g_value_unset( &value ); |
| return( -1 ); |
| } |
| g_value_unset( &value ); |
| |
| return( 0 ); |
| </pre></div> |
| <p> |
| </p> |
| <p> |
| See also: <a class="link" href="libvips-meta.html#im-meta-get" title="im_meta_get ()"><code class="function">im_meta_get()</code></a>. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>im</code></em> :</span></p></td> |
| <td>image to set the metadata on |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>field</code></em> :</span></p></td> |
| <td>the name to give the metadata |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>value</code></em> :</span></p></td> |
| <td>the GValue to copy into the image |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> 0 on success, -1 otherwise. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_meta_remove ()"> |
| <a name="im-meta-remove"></a><h3>im_meta_remove ()</h3> |
| <pre class="programlisting"><span class="returnvalue">gboolean</span> im_meta_remove (<em class="parameter"><code><span class="type">IMAGE</span> *im</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>);</pre> |
| <p> |
| Find and remove an item of metadata. Return <code class="literal">FALSE</code> if no metadata of that |
| name was found. |
| </p> |
| <p> |
| See also: <a class="link" href="libvips-meta.html#im-meta-set" title="im_meta_set ()"><code class="function">im_meta_set()</code></a>, <a class="link" href="libvips-meta.html#im-meta-get-typeof" title="im_meta_get_typeof ()"><code class="function">im_meta_get_typeof()</code></a>. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>im</code></em> :</span></p></td> |
| <td>image to test |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>field</code></em> :</span></p></td> |
| <td>the name to search for |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> <code class="literal">TRUE</code> if an item of metadata of that name was found and removed |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_meta_get ()"> |
| <a name="im-meta-get"></a><h3>im_meta_get ()</h3> |
| <pre class="programlisting"><span class="returnvalue">int</span> im_meta_get (<em class="parameter"><code><span class="type">IMAGE</span> *Param1</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>, |
| <em class="parameter"><code><span class="type">GValue</span> *Param3</code></em>);</pre> |
| <p> |
| Fill <em class="parameter"><code>value_copy</code></em> with a copy of the metadata. <em class="parameter"><code>value_copy</code></em> must be zeroed |
| but uninitialised. |
| </p> |
| <p> |
| This will return -1 and add a message to the error buffer if the item |
| of metadata does not exist. Use <a class="link" href="libvips-meta.html#im-meta-get-typeof" title="im_meta_get_typeof ()"><code class="function">im_meta_get_typeof()</code></a> to test for the |
| existence |
| of a piece of metadata first if you are not certain it will be there. |
| </p> |
| <p> |
| For example, to read a double from an image (though of course you would use |
| <a class="link" href="libvips-meta.html#im-meta-get-double" title="im_meta_get_double ()"><code class="function">im_meta_get_double()</code></a> in practice): |
| </p> |
| <p> |
| </p> |
| <div class="informalexample"><pre class="programlisting"> |
| GValue value = { 0 }; |
| double d; |
| |
| if( im_meta_get( im, field, &value ) ) |
| return( -1 ); |
| |
| if( G_VALUE_TYPE( &value ) != G_TYPE_DOUBLE ) { |
| im_error( "mydomain", _( "field \"%s\" is of type %s, not double" ), |
| field, g_type_name( G_VALUE_TYPE( &value ) ) ); |
| g_value_unset( &value ); |
| return( -1 ); |
| } |
| |
| d = g_value_get_double( &value ); |
| g_value_unset( &value ); |
| |
| return( 0 ); |
| </pre></div> |
| <p> |
| </p> |
| <p> |
| See also: <a class="link" href="libvips-meta.html#im-meta-get-typeof" title="im_meta_get_typeof ()"><code class="function">im_meta_get_typeof()</code></a>, <a class="link" href="libvips-meta.html#im-meta-set" title="im_meta_set ()"><code class="function">im_meta_set()</code></a>. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>im</code></em> :</span></p></td> |
| <td>image to get the metadata from |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>field</code></em> :</span></p></td> |
| <td>the name to give the metadata |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>value_copy</code></em> :</span></p></td> |
| <td>the GValue is copied into this |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> 0 on success, -1 otherwise. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_meta_get_typeof ()"> |
| <a name="im-meta-get-typeof"></a><h3>im_meta_get_typeof ()</h3> |
| <pre class="programlisting"><span class="returnvalue">GType</span> im_meta_get_typeof (<em class="parameter"><code><span class="type">IMAGE</span> *im</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>);</pre> |
| <p> |
| Read the GType for an item of metadata. Returns zero if there is no |
| metadata of that name. |
| </p> |
| <p> |
| See also: <a class="link" href="libvips-meta.html#im-meta-get" title="im_meta_get ()"><code class="function">im_meta_get()</code></a>. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>im</code></em> :</span></p></td> |
| <td>image to test |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>field</code></em> :</span></p></td> |
| <td>the name to search for |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> the GType of the metadata, or zero if there is no |
| metadata of that name. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_meta_set_int ()"> |
| <a name="im-meta-set-int"></a><h3>im_meta_set_int ()</h3> |
| <pre class="programlisting"><span class="returnvalue">int</span> im_meta_set_int (<em class="parameter"><code><span class="type">IMAGE</span> *Param1</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>, |
| <em class="parameter"><code><span class="type">int</span> i</code></em>);</pre> |
| <p> |
| Attaches <em class="parameter"><code>i</code></em> as a metadata item on <em class="parameter"><code>im</code></em> under the name <em class="parameter"><code>field</code></em>. A convenience |
| function over <a class="link" href="libvips-meta.html#im-meta-set" title="im_meta_set ()"><code class="function">im_meta_set()</code></a>. |
| </p> |
| <p> |
| See also: <a class="link" href="libvips-meta.html#im-meta-get-int" title="im_meta_get_int ()"><code class="function">im_meta_get_int()</code></a>, <a class="link" href="libvips-meta.html#im-meta-set" title="im_meta_set ()"><code class="function">im_meta_set()</code></a> |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>im</code></em> :</span></p></td> |
| <td>image to attach the metadata to |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>field</code></em> :</span></p></td> |
| <td>metadata name |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>i</code></em> :</span></p></td> |
| <td>metadata value |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> 0 on success, -1 otherwise. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_meta_get_int ()"> |
| <a name="im-meta-get-int"></a><h3>im_meta_get_int ()</h3> |
| <pre class="programlisting"><span class="returnvalue">int</span> im_meta_get_int (<em class="parameter"><code><span class="type">IMAGE</span> *Param1</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>, |
| <em class="parameter"><code><span class="type">int</span> *i</code></em>);</pre> |
| <p> |
| Gets <em class="parameter"><code>i</code></em> from <em class="parameter"><code>im</code></em> under the name <em class="parameter"><code>field</code></em>. A convenience |
| function over <a class="link" href="libvips-meta.html#im-meta-get" title="im_meta_get ()"><code class="function">im_meta_get()</code></a>. Use <a class="link" href="libvips-meta.html#im-meta-get-typeof" title="im_meta_get_typeof ()"><code class="function">im_meta_get_typeof()</code></a> to test for the |
| existance |
| of a piece of metadata. |
| </p> |
| <p> |
| See also: <a class="link" href="libvips-meta.html#im-meta-set-int" title="im_meta_set_int ()"><code class="function">im_meta_set_int()</code></a>, <a class="link" href="libvips-meta.html#im-meta-get" title="im_meta_get ()"><code class="function">im_meta_get()</code></a>, <a class="link" href="libvips-meta.html#im-meta-get-typeof" title="im_meta_get_typeof ()"><code class="function">im_meta_get_typeof()</code></a> |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>im</code></em> :</span></p></td> |
| <td>image to get the metadata from |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>field</code></em> :</span></p></td> |
| <td>metadata name |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>i</code></em> :</span></p></td> |
| <td>return metadata value |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> 0 on success, -1 otherwise. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_meta_set_double ()"> |
| <a name="im-meta-set-double"></a><h3>im_meta_set_double ()</h3> |
| <pre class="programlisting"><span class="returnvalue">int</span> im_meta_set_double (<em class="parameter"><code><span class="type">IMAGE</span> *Param1</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>, |
| <em class="parameter"><code><span class="type">double</span> d</code></em>);</pre> |
| <p> |
| Attaches <em class="parameter"><code>d</code></em> as a metadata item on <em class="parameter"><code>im</code></em> under the name <em class="parameter"><code>field</code></em>. A convenience |
| function over <a class="link" href="libvips-meta.html#im-meta-set" title="im_meta_set ()"><code class="function">im_meta_set()</code></a>. |
| </p> |
| <p> |
| See also: <a class="link" href="libvips-meta.html#im-meta-get-double" title="im_meta_get_double ()"><code class="function">im_meta_get_double()</code></a>, <a class="link" href="libvips-meta.html#im-meta-set" title="im_meta_set ()"><code class="function">im_meta_set()</code></a> |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>im</code></em> :</span></p></td> |
| <td>image to attach the metadata to |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>field</code></em> :</span></p></td> |
| <td>metadata name |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>d</code></em> :</span></p></td> |
| <td>metadata value |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> 0 on success, -1 otherwise. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_meta_get_double ()"> |
| <a name="im-meta-get-double"></a><h3>im_meta_get_double ()</h3> |
| <pre class="programlisting"><span class="returnvalue">int</span> im_meta_get_double (<em class="parameter"><code><span class="type">IMAGE</span> *Param1</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>, |
| <em class="parameter"><code><span class="type">double</span> *d</code></em>);</pre> |
| <p> |
| Gets <em class="parameter"><code>d</code></em> from <em class="parameter"><code>im</code></em> under the name <em class="parameter"><code>field</code></em>. A convenience |
| function over <a class="link" href="libvips-meta.html#im-meta-get" title="im_meta_get ()"><code class="function">im_meta_get()</code></a>. Use <a class="link" href="libvips-meta.html#im-meta-get-typeof" title="im_meta_get_typeof ()"><code class="function">im_meta_get_typeof()</code></a> to test for the |
| existance |
| of a piece of metadata. |
| </p> |
| <p> |
| See also: <a class="link" href="libvips-meta.html#im-meta-set-double" title="im_meta_set_double ()"><code class="function">im_meta_set_double()</code></a>, <a class="link" href="libvips-meta.html#im-meta-get" title="im_meta_get ()"><code class="function">im_meta_get()</code></a>, <a class="link" href="libvips-meta.html#im-meta-get-typeof" title="im_meta_get_typeof ()"><code class="function">im_meta_get_typeof()</code></a> |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>im</code></em> :</span></p></td> |
| <td>image to get the metadata from |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>field</code></em> :</span></p></td> |
| <td>metadata name |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>d</code></em> :</span></p></td> |
| <td>return metadata value |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> 0 on success, -1 otherwise. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_meta_set_area ()"> |
| <a name="im-meta-set-area"></a><h3>im_meta_set_area ()</h3> |
| <pre class="programlisting"><span class="returnvalue">int</span> im_meta_set_area (<em class="parameter"><code><span class="type">IMAGE</span> *Param1</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>, |
| <em class="parameter"><code><a class="link" href="libvips-callback.html#im-callback-fn" title="im_callback_fn ()"><span class="type">im_callback_fn</span></a> Param3</code></em>, |
| <em class="parameter"><code><span class="type">void</span> *Param4</code></em>);</pre> |
| <p> |
| Attaches <em class="parameter"><code>data</code></em> as a metadata item on <em class="parameter"><code>im</code></em> under the name <em class="parameter"><code>field</code></em>. When VIPS |
| no longer needs the metadata, it will be freed with <em class="parameter"><code>free_fn</code></em>. |
| </p> |
| <p> |
| See also: <a class="link" href="libvips-meta.html#im-meta-get-double" title="im_meta_get_double ()"><code class="function">im_meta_get_double()</code></a>, <a class="link" href="libvips-meta.html#im-meta-set" title="im_meta_set ()"><code class="function">im_meta_set()</code></a> |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>im</code></em> :</span></p></td> |
| <td>image to attach the metadata to |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>field</code></em> :</span></p></td> |
| <td>metadata name |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>free_fn</code></em> :</span></p></td> |
| <td>free function for <em class="parameter"><code>data</code></em> |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>data</code></em> :</span></p></td> |
| <td>pointer to area of memory |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> 0 on success, -1 otherwise. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_meta_get_area ()"> |
| <a name="im-meta-get-area"></a><h3>im_meta_get_area ()</h3> |
| <pre class="programlisting"><span class="returnvalue">int</span> im_meta_get_area (<em class="parameter"><code><span class="type">IMAGE</span> *Param1</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>, |
| <em class="parameter"><code><span class="type">void</span> **data</code></em>);</pre> |
| <p> |
| Gets <em class="parameter"><code>data</code></em> from <em class="parameter"><code>im</code></em> under the name <em class="parameter"><code>field</code></em>. A convenience |
| function over <a class="link" href="libvips-meta.html#im-meta-get" title="im_meta_get ()"><code class="function">im_meta_get()</code></a>. Use <a class="link" href="libvips-meta.html#im-meta-get-typeof" title="im_meta_get_typeof ()"><code class="function">im_meta_get_typeof()</code></a> to test for the |
| existance |
| of a piece of metadata. |
| </p> |
| <p> |
| See also: <a class="link" href="libvips-meta.html#im-meta-set-area" title="im_meta_set_area ()"><code class="function">im_meta_set_area()</code></a>, <a class="link" href="libvips-meta.html#im-meta-get" title="im_meta_get ()"><code class="function">im_meta_get()</code></a>, <a class="link" href="libvips-meta.html#im-meta-get-typeof" title="im_meta_get_typeof ()"><code class="function">im_meta_get_typeof()</code></a> |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>im</code></em> :</span></p></td> |
| <td>image to get the metadata from |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>field</code></em> :</span></p></td> |
| <td>metadata name |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>data</code></em> :</span></p></td> |
| <td>return metadata value |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> 0 on success, -1 otherwise. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_meta_set_string ()"> |
| <a name="im-meta-set-string"></a><h3>im_meta_set_string ()</h3> |
| <pre class="programlisting"><span class="returnvalue">int</span> im_meta_set_string (<em class="parameter"><code><span class="type">IMAGE</span> *Param1</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *str</code></em>);</pre> |
| <p> |
| Attaches <em class="parameter"><code>str</code></em> as a metadata item on <em class="parameter"><code>im</code></em> under the name <em class="parameter"><code>field</code></em>. A convenience |
| function over <a class="link" href="libvips-meta.html#im-meta-set" title="im_meta_set ()"><code class="function">im_meta_set()</code></a> using an im_ref_string. |
| </p> |
| <p> |
| See also: <a class="link" href="libvips-meta.html#im-meta-get-double" title="im_meta_get_double ()"><code class="function">im_meta_get_double()</code></a>, <a class="link" href="libvips-meta.html#im-meta-set" title="im_meta_set ()"><code class="function">im_meta_set()</code></a>, im_ref_string |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>im</code></em> :</span></p></td> |
| <td>image to attach the metadata to |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>field</code></em> :</span></p></td> |
| <td>metadata name |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>str</code></em> :</span></p></td> |
| <td>metadata value |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> 0 on success, -1 otherwise. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_meta_get_string ()"> |
| <a name="im-meta-get-string"></a><h3>im_meta_get_string ()</h3> |
| <pre class="programlisting"><span class="returnvalue">int</span> im_meta_get_string (<em class="parameter"><code><span class="type">IMAGE</span> *Param1</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>, |
| <em class="parameter"><code><span class="type">char</span> **str</code></em>);</pre> |
| <p> |
| Gets <em class="parameter"><code>str</code></em> from <em class="parameter"><code>im</code></em> under the name <em class="parameter"><code>field</code></em>. A convenience |
| function over <a class="link" href="libvips-meta.html#im-meta-get" title="im_meta_get ()"><code class="function">im_meta_get()</code></a>. Use <a class="link" href="libvips-meta.html#im-meta-get-typeof" title="im_meta_get_typeof ()"><code class="function">im_meta_get_typeof()</code></a> to test for the |
| existance |
| of a piece of metadata. |
| </p> |
| <p> |
| See also: <a class="link" href="libvips-meta.html#im-meta-set-string" title="im_meta_set_string ()"><code class="function">im_meta_set_string()</code></a>, <a class="link" href="libvips-meta.html#im-meta-get" title="im_meta_get ()"><code class="function">im_meta_get()</code></a>, <a class="link" href="libvips-meta.html#im-meta-get-typeof" title="im_meta_get_typeof ()"><code class="function">im_meta_get_typeof()</code></a>, |
| im_ref_string |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>im</code></em> :</span></p></td> |
| <td>image to get the metadata from |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>field</code></em> :</span></p></td> |
| <td>metadata name |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>str</code></em> :</span></p></td> |
| <td>return metadata value |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> 0 on success, -1 otherwise. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_meta_set_blob ()"> |
| <a name="im-meta-set-blob"></a><h3>im_meta_set_blob ()</h3> |
| <pre class="programlisting"><span class="returnvalue">int</span> im_meta_set_blob (<em class="parameter"><code><span class="type">IMAGE</span> *im</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>, |
| <em class="parameter"><code><a class="link" href="libvips-callback.html#im-callback-fn" title="im_callback_fn ()"><span class="type">im_callback_fn</span></a> free_fn</code></em>, |
| <em class="parameter"><code><span class="type">void</span> *blob</code></em>, |
| <em class="parameter"><code><span class="type">size_t</span> blob_length</code></em>);</pre> |
| <p> |
| Attaches <em class="parameter"><code>blob</code></em> as a metadata item on <em class="parameter"><code>im</code></em> under the name <em class="parameter"><code>field</code></em>. A convenience |
| function over <a class="link" href="libvips-meta.html#im-meta-set" title="im_meta_set ()"><code class="function">im_meta_set()</code></a> using an im_blob. |
| </p> |
| <p> |
| See also: <a class="link" href="libvips-meta.html#im-meta-get-blob" title="im_meta_get_blob ()"><code class="function">im_meta_get_blob()</code></a>, <a class="link" href="libvips-meta.html#im-meta-set" title="im_meta_set ()"><code class="function">im_meta_set()</code></a>, im_blob |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>im</code></em> :</span></p></td> |
| <td>image to attach the metadata to |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>field</code></em> :</span></p></td> |
| <td>metadata name |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>free_fn</code></em> :</span></p></td> |
| <td>free function for <em class="parameter"><code>data</code></em> |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>blob</code></em> :</span></p></td> |
| <td>pointer to area of memory |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>blob_length</code></em> :</span></p></td> |
| <td>length of memory area |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> 0 on success, -1 otherwise. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="im_meta_get_blob ()"> |
| <a name="im-meta-get-blob"></a><h3>im_meta_get_blob ()</h3> |
| <pre class="programlisting"><span class="returnvalue">int</span> im_meta_get_blob (<em class="parameter"><code><span class="type">IMAGE</span> *im</code></em>, |
| <em class="parameter"><code>const <span class="type">char</span> *field</code></em>, |
| <em class="parameter"><code><span class="type">void</span> **blob</code></em>, |
| <em class="parameter"><code><span class="type">size_t</span> *blob_length</code></em>);</pre> |
| <p> |
| Gets <em class="parameter"><code>blob</code></em> from <em class="parameter"><code>im</code></em> under the name <em class="parameter"><code>field</code></em>, optionally return its length in |
| <em class="parameter"><code>blob_length</code></em>. A convenience |
| function over <a class="link" href="libvips-meta.html#im-meta-get" title="im_meta_get ()"><code class="function">im_meta_get()</code></a>. Use <a class="link" href="libvips-meta.html#im-meta-get-typeof" title="im_meta_get_typeof ()"><code class="function">im_meta_get_typeof()</code></a> to test for the |
| existance |
| of a piece of metadata. |
| </p> |
| <p> |
| See also: <a class="link" href="libvips-meta.html#im-meta-get" title="im_meta_get ()"><code class="function">im_meta_get()</code></a>, <a class="link" href="libvips-meta.html#im-meta-get-typeof" title="im_meta_get_typeof ()"><code class="function">im_meta_get_typeof()</code></a>, <a class="link" href="libvips-meta.html#im-blob-get" title="im_blob_get ()"><code class="function">im_blob_get()</code></a>, im_blob |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>im</code></em> :</span></p></td> |
| <td>image to get the metadata from |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>field</code></em> :</span></p></td> |
| <td>metadata name |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>blob</code></em> :</span></p></td> |
| <td>pointer to area of memory |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>blob_length</code></em> :</span></p></td> |
| <td>return the blob length here, optionally |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> 0 on success, -1 otherwise. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| </div> |
| <div class="refsect1" title="See Also"> |
| <a name="libvips-meta.see-also"></a><h2>See Also</h2> |
| <a class="link" href="libvips-header.html" title="header">header</a> |
| </div> |
| </div> |
| <div class="footer"> |
| <hr> |
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