png_set_pHYs
Name
png_set_pHYs -- set physical resolution
Synopsis
void
png_set_pHYs
(png_structp
png_ptr, png_infop
info_ptr, png_uint_32
res_x, png_uint_32
res_y, int
unit_type);
Description
png_set_pHYs() sets the physical resolution for the image in pixels per unit.
The physical resolution in x direction is set to res_x and that in y direction
is set to res_y. unit_type must be set to PNG_RESOLUTION_METER is the unit for
resolution is pixels per unit, otherwise unit_type must be set to
PNG_RESOLUTION_UNKNOWN.