im_png2vips_header3
Convert png images to and from vips format
Part of im_png2vips(3).
Usage
#include <vips/vips.h>
int im_png2vips( const char *filename, IMAGE *out )
int im_png2vips_header( const char *filename, IMAGE *out )
int im_vips2png( IMAGE *in, const char *filename )
Overview
im_png2vips() reads the png image in filename, and writes the image out in VIPS format.
im_png2vips_header() reads just the header information from the PNG file. You can't read any pixels!
im_vips2png() reads the image in and writes a PNG file to the specified filename. The filename may include an optional mode string, following a ':' character, which you can use to specify compression and interlace.
The mode string has the following syntax:
<compression>,<interlace>
where <compression> is an integer between 0 and 9 specifying the amount of compression (6 is the default), and <interlace> is 0 for no interlace (this is the default) and 1 for ADAM7 interlace.
Beware that writing an interlaced image is potentially up to 7 times slower than writing a non-interlaced image.
The image is automatically converted to RGB or Monochrome (with an optional alpha channel) before saving.
Examples
The call:
im_vips2png fred.v fred.png
Writes a compression 6, uninterlaced PNG image.
im_vips2png fred.v fred.tif:,1
Writes an interlaced image.
Releases
3 releases since Debian 3.1 (Sarge); the text changed 1 time.