mewin/libpng
1
0
Fork 0
mirror of https://git.code.sf.net/p/libpng/code.git synced 2025-07-10 18:04:09 +02:00
Code Issues Projects Releases Wiki Activity

[devel] Make the 16-to-8 scaling accurate. Dividing by 256 with no rounding is

Browse Source 
wrong (high by one) 25% of the time. Dividing by 257 with rounding is
    wrong in 128 out of 65536 cases. Getting the right answer all the time
    without division is easy.
This commit is contained in:
John Bowler
2011-06-10 23:24:58 -05:00
committed by Glenn Randers-Pehrson
parent cc2770850a
commit b2bee3374c
12 changed files with 81 additions and 55 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
scripts/pnglibconf.dfa
View File

@@ -346,12 +346,15 @@ option INCH_CONVERSIONS
option BUILD_GRAYSCALE_PALETTE
# This is no longer used - the scaling is always accurate - but the definition
# is left in for older applications (including pngvalid) that check it. Do not
# turn it off!
option READ_16_TO_8_ACCURATE_SCALE requires READ
# IN DEVELOPMENT
# These are currently experimental features, define them if you want
# These are currently experimental features; define them if you want
# Very little testing, not enabled by default.
option READ_16_TO_8_ACCURATE_SCALE requires READ disabled
# NOTHING HERE
# WRITE options