PNG_INTRAPIXEL_DIFFERENCING 2543 png.c                    (filter_type == PNG_INTRAPIXEL_DIFFERENCING) &&
PNG_INTRAPIXEL_DIFFERENCING  553 pngread.c             (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
PNG_INTRAPIXEL_DIFFERENCING  865 pngwrite.c            (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
PNG_INTRAPIXEL_DIFFERENCING  999 pngwrite.c            (method == PNG_INTRAPIXEL_DIFFERENCING))
PNG_INTRAPIXEL_DIFFERENCING  856 pngwutil.c            (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) &&