[devel] Revised commentary about png_rgb_to_gray coefficents
and fixed spelling (truely -> truly) in comments.
diff --git a/pngrtran.c b/pngrtran.c
index 67813b5..74e80cb 100644
--- a/pngrtran.c
+++ b/pngrtran.c
@@ -3093,6 +3093,11 @@
*
* Y = (6968 * R + 23434 * G + 2366 * B)/32768
*
+ * Starting with libpng-1.5.4, if the image being converted has the
+ * sRGB chunk, then the sRGB numbers are used by default:
+ *
+ * Y = 0.33000*R + 0.60000*G + 0.06000*B
+ *
* The calculation is to be done in a linear colorspace.
*
* Other integer coefficents can be used via png_set_rgb_to_gray().
diff --git a/pngset.c b/pngset.c
index 7eaad7d..08d8ff4 100644
--- a/pngset.c
+++ b/pngset.c
@@ -99,7 +99,7 @@
* possible for 1/gamma to overflow the limit of 21474 and this means the
* gamma value must be at least 5/100000 and hence at most 20000.0. For
* safety the limits here are a little narrower. The values are 0.00016 to
- * 6250.0, which are truely ridiculous gammma values (and will produce
+ * 6250.0, which are truly ridiculous gammma values (and will produce
* displays that are all black or all white.)
*/
if (file_gamma < 16 || file_gamma > 625000000)
diff --git a/pngvalid.c b/pngvalid.c
index 138bfd0..9da69dd 100644
--- a/pngvalid.c
+++ b/pngvalid.c
@@ -2104,7 +2104,7 @@
png_error(pp, "store state damaged (progressive)");
/* This is another Horowitz and Hill random noise generator. In this case
- * the aim is to stress the progressive reader with truely horrible variable
+ * the aim is to stress the progressive reader with truly horrible variable
* buffer sizes in the range 1..500, so a sequence of 9 bit random numbers
* is generated. We could probably just count from 1 to 32767 and get as
* good a result.
