jpeg pushed a commit to branch master. http://git.enlightenment.org/core/efl.git/commit/?id=a9558235f618ba62d9827407f15311c8bef04bec
commit a9558235f618ba62d9827407f15311c8bef04bec Author: Jean-Philippe Andre <[email protected]> Date: Mon Feb 24 13:54:30 2014 +0900 Evas filters: Improve RGBA to alpha conversion (visual quality) Add weights to the R,G,B components when converting to greyscale. The weights are those used in the RGB to YCbCr conversion formula. --- src/lib/evas/filters/evas_filter_blend.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/src/lib/evas/filters/evas_filter_blend.c b/src/lib/evas/filters/evas_filter_blend.c index 038eb5f..66e8caf 100644 --- a/src/lib/evas/filters/evas_filter_blend.c +++ b/src/lib/evas/filters/evas_filter_blend.c @@ -2,6 +2,9 @@ #include "evas_filter_private.h" #include "evas_blend_private.h" +// Use a better formula than R+G+B for rgba to alpha conversion (RGB to YCbCr) +#define RGBA2ALPHA_WEIGHTED 1 + #if DIV_USING_BITSHIFT static int _smallest_pow2_larger_than(int val) @@ -177,7 +180,16 @@ _image_draw_cpu_rgba2alpha(void *data EINA_UNUSED, void *context EINA_UNUSED, DATA32* srcdata = src->image.data; DATA8* dstdata = dst->mask.data; int x, y, sw, dw; - DEFINE_DIVIDER(3); +#if RGBA2ALPHA_WEIGHTED + const int WR = 299; + const int WG = 587; + const int WB = 114; +#else + const int WR = 1; + const int WG = 1; + const int WB = 1; +#endif + DEFINE_DIVIDER(WR + WG + WB); EINA_SAFETY_ON_FALSE_RETURN_VAL((src_w == dst_w) && (src_h == dst_h), EINA_FALSE); @@ -191,10 +203,7 @@ _image_draw_cpu_rgba2alpha(void *data EINA_UNUSED, void *context EINA_UNUSED, DATA32 *s = srcdata + src_x; DATA8 *d = dstdata + dst_x; for (x = src_w; x; x--, d++, s++) - { - // TODO: Add weights like in YUV <--> RGB? - *d = DIVIDE(R_VAL(s) + G_VAL(s) + B_VAL(s)); - } + *d = DIVIDE((R_VAL(s) * WR) + (G_VAL(s) * WG) + (B_VAL(s) * WB)); srcdata += sw; dstdata += dw; } --
