From 101df25fde2a05f28884facfd0e9b51b8198096f Mon Sep 17 00:00:00 2001 From: Frank Bossen Date: Tue, 29 Apr 2014 14:03:34 -0400 Subject: [PATCH] Modify trellis parameter defaults Modify trellis parameters to optimize for PSNR-HVS by default --- cjpeg.c | 4 ++-- jcparam.c | 5 +++-- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/cjpeg.c b/cjpeg.c index 23901951..bb9947c1 100644 --- a/cjpeg.c +++ b/cjpeg.c @@ -487,8 +487,8 @@ parse_switches (j_compress_ptr cinfo, int argc, char **argv, } else if (keymatch(arg, "tune-hvs-psnr", 6)) { cinfo->use_flat_quant_tbl = FALSE; - cinfo->lambda_log_scale1 = 15.0; - cinfo->lambda_log_scale2 = 14.5; + cinfo->lambda_log_scale1 = 16.0; + cinfo->lambda_log_scale2 = 15.5; cinfo->use_lambda_weight_tbl = TRUE; jpeg_set_quality(cinfo, 75, TRUE); diff --git a/jcparam.c b/jcparam.c index afe21026..3020aab9 100644 --- a/jcparam.c +++ b/jcparam.c @@ -427,9 +427,10 @@ jpeg_set_defaults (j_compress_ptr cinfo) #endif cinfo->trellis_quant = (cinfo->use_moz_defaults != 0) ? TRUE : FALSE; - cinfo->lambda_log_scale1 = 17.0; - cinfo->lambda_log_scale2 = 15.0; + cinfo->lambda_log_scale1 = 16.0; + cinfo->lambda_log_scale2 = 15.5; + cinfo->use_lambda_weight_tbl = TRUE; cinfo->use_scans_in_trellis = FALSE; cinfo->trellis_freq_split = 8; cinfo->trellis_num_loops = 1;