png_get_x_pixels_per_meter 2049 3rdparty/libpng/png.h PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter,
png_get_x_pixels_per_meter  318 3rdparty/libpng/pngget.c    return ppi_from_ppm(png_get_x_pixels_per_meter(png_ptr, info_ptr));