| .TH IM_DISP_PS 3 "23 May 1991" |
| .SH NAME |
| im_disp_ps \- creates a displayable power spectrum of an one band image |
| .SH SYNOPSIS |
| .B #include <vips/vips.h> |
| |
| .B int im_disp_ps(in, out) |
| .br |
| .B IMAGE *in, *out; |
| .SH DESCRIPTION |
| im_disp_ps() creates a displayable power spectrum of the image held by the |
| image descriptor in. The resultant unsigned char image is written on the |
| image descriptor out. Input should be one band image of any non-complex |
| type. |
| |
| The function finds the fourier transform of the input (if in is not complex) |
| and then the amplitude power spectrum is created (im_c2ps(3)). The power |
| spectrum is passed through a non-linear transformation (im_scaleps(3)). The |
| final image has the four quadrants rotated in such a way that the coordinate |
| (0,0) is near the centre of the image (im_rotquad(3)). |
| |
| Input should be a square image with size power of 2. |
| The maximum size of the input image is dictated by the available RAM. |
| .SH RETURN VALUE |
| The function returns 0 on success and -1 on error. |
| .SH SEE ALSO |
| im_fwfft(3), im_c2ps(3), im_scaleps(3), im_rotquad(3). |
| .SH COPYRIGHT |
| .br |
| N. Dessipris |
| .SH AUTHOR |
| N. Dessipris \- 23/05/1991 |
