| /* im_LabQ2Lab |
| * |
| * Copyright Kirk Martinez 2/5/1993 |
| * |
| * Modified: 16/6/93 |
| * 7/6/93 JC |
| * - adapted for partial v2 |
| * 16/11/94 JC |
| * - adapted to new im_wrap_oneonebuf() function. |
| * 9/2/95 JC |
| * - new im_wrapone function |
| * 22/5/95 JC |
| * - changed char to unsigned char for RS/6000 |
| * - small tidies and speed-ups |
| * 4/9/97 JC |
| * - L* = 100.0 now handled correctly |
| * 2/11/09 |
| * - gtkdoc |
| */ |
| |
| /* |
| |
| This file is part of VIPS. |
| |
| VIPS is free software; you can redistribute it and/or modify |
| it under the terms of the GNU Lesser General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| |
| */ |
| |
| /* |
| |
| These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk |
| |
| */ |
| |
| #ifdef HAVE_CONFIG_H |
| #include <config.h> |
| #endif /*HAVE_CONFIG_H*/ |
| #include <vips/intl.h> |
| |
| #include <stdio.h> |
| |
| #include <vips/vips.h> |
| |
| #ifdef WITH_DMALLOC |
| #include <dmalloc.h> |
| #endif /*WITH_DMALLOC*/ |
| |
| /* imb_LabQ2Lab: CONVERT n pels from packed 32bit Lab to float values |
| * in a buffer |
| * ARGS: PEL *inp pointer to first byte of Lab32 buffer |
| * float *outbuf destination buffer |
| * int n number of pels to process |
| * (C) K.Martinez 2/5/93 |
| */ |
| void |
| imb_LabQ2Lab( PEL *inp, float *outbuf, int n ) |
| { |
| signed char *b; /* to read input bytes */ |
| int l; |
| int lsbs; /* for lsbs byte */ |
| int c; /* counter */ |
| float *out; |
| |
| /* Read input with a signed pointer to get signed ab easily. |
| */ |
| b = (signed char *) inp; |
| out = outbuf; |
| for( c = 0; c < n; c++ ) { |
| /* Get extra bits. |
| */ |
| lsbs = ((unsigned char *) b)[3]; |
| |
| /* Build L. |
| */ |
| l = ((unsigned char *)b)[0]; |
| l = (l << 2) | (lsbs >> 6); |
| out[0] = (float) l * (100.0 / 1023.0); |
| |
| /* Build a. |
| */ |
| l = (b[1] << 3) | ((lsbs >> 3) & 0x7); |
| out[1] = (float) l * 0.125; |
| |
| /* And b. |
| */ |
| l = (b[2] << 3) | (lsbs & 0x7); |
| out[2] = (float) l * 0.125; |
| |
| b += 4; |
| out += 3; |
| } |
| } |
| |
| /** |
| * im_LabQ2Lab: |
| * @in: input image |
| * @out: output image |
| * |
| * Unpack a LabQ (#IM_CODING_LABQ) image to a three-band float image. |
| * |
| * See also: im_LabQ2Lab(), im_LabQ2LabS(), im_rad2float(). |
| * |
| * Returns: 0 on success, -1 on error. |
| */ |
| int |
| im_LabQ2Lab( IMAGE *in, IMAGE *out ) |
| { |
| if( im_check_coding_labq( "im_LabQ2Lab", in ) ) |
| return( -1 ); |
| |
| if( im_cp_desc( out, in ) ) |
| return( -1 ); |
| out->Bands = 3; |
| out->Type = IM_TYPE_LAB; |
| out->BandFmt = IM_BANDFMT_FLOAT; |
| out->Coding = IM_CODING_NONE; |
| |
| if( im_wrapone( in, out, |
| (im_wrapone_fn) imb_LabQ2Lab, NULL, NULL ) ) |
| return( -1 ); |
| |
| return( 0 ); |
| } |