Archives/notcurses
2
0
Fork 0
mirror of https://github.com/dankamongmen/notcurses.git synced 2024-11-06 03:20:26 +00:00
Code Issues Packages Projects Releases Wiki Activity

rgb_greyscale: linear approximation to gamma decomp

Browse Source
This commit is contained in:
nick black 2020-01-17 04:51:51 -05:00 committed by Nick Black
parent fe2dcc3387
commit 5d69545f22
2 changed files with 4 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
src/demo/boxdemo.c
View File

@ -18,8 +18,8 @@ int box_demo(struct notcurses* nc){
}
struct timespec start, now;
clock_gettime(CLOCK_MONOTONIC, &start);
int zbonus = 0;
int zbonusdelta = 16;
int zbonus = 40;
int zbonusdelta = 20;
int ylen, xlen;
ncplane_dim_yx(n, &ylen, &xlen);
// target grid is 7x7

4
src/lib/notcurses.c
View File

@ -1718,7 +1718,8 @@ rgb_greyscale(int r, int g, int b){
if(b < 0 || b > 255){
return -1;
}
float fg = (0.2126 * (r / 255.0) + 0.7152 * (g / 255.0) + 0.0722 * (b / 255.0));
// Use Rec. 601 scaling plus linear approximation of gamma decompression
float fg = (0.299 * (r / 255.0) + 0.587 * (g / 255.0) + 0.114 * (b / 255.0));
return fg * 255;
}
@ -1729,7 +1730,6 @@ void ncplane_greyscale(ncplane *n){
cell* c = &n->fb[nfbcellidx(n, y, x)];
unsigned r, g, b;
cell_fg_rgb(c, &r, &g, &b);
// Use Rec. 601 scaling
int gy = rgb_greyscale(r, g, b);
cell_set_fg_rgb(c, gy, gy, gy);
cell_bg_rgb(c, &r, &g, &b);