im_png(3)

NAME

im_png2vips, im_png2vips_header, im_png2vips - convert PNG images to and from VIPS format

SYNOPSIS

#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 )

DESCRIPTION

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.

SEE ALSO

im_ispng(3), im_vips2tiff(3)

COPYRIGHT

Hey, you want this? You have it!

3 Jan 2003 IM_PNG(3)