improved png compression ratio (ticket #1452)

13 years ago · 17c3102705
parent 3f22a1c40f
commit 17c3102705
1 changed files with 1 additions and 1 deletions
--- a/modules/highgui/src/grfmt_png.cpp
+++ b/modules/highgui/src/grfmt_png.cpp
@ -366,7 +366,7 @@ bool  PngEncoder::write( const Mat& img, const vector<int>& params )
                        png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, PNG_FILTER_SUB);
                        png_set_compression_level(png_ptr, Z_BEST_SPEED);
                    }
-                    png_set_compression_strategy(png_ptr, Z_HUFFMAN_ONLY);
+                    png_set_compression_strategy(png_ptr, Z_FILTERED);

                    png_set_IHDR( png_ptr, info_ptr, width, height, depth == CV_8U ? 8 : 16,
                        channels == 1 ? PNG_COLOR_TYPE_GRAY :