49 lines
1.6 KiB
Plaintext
49 lines
1.6 KiB
Plaintext
|
|
Known bugs and suggested enhancements in libpng-1.0.8
|
|
|
|
1. July 2, 2000 -- BUG -- pnggccrd.c
|
|
|
|
The png_read_filter() function has still not been fully converted and
|
|
will not compile under gcc-2.95.2; it is currently ifdef'ed out.
|
|
|
|
STATUS: Under investigation. Experts on MMX assembler code are
|
|
invited to help with the debugging. Note that pngvcrd.c works fine.
|
|
|
|
2. March 15, 1998 -- OPTIMIZATION -- Kevin Bracey
|
|
|
|
Loops need to be optimized everywhere
|
|
|
|
Make them count down instead of up -- Kevin Bracey
|
|
|
|
Optimizing compilers don't need this, and making
|
|
the change would be error prone -- Tom Lane, Glenn R-P
|
|
|
|
Question whether i-- or --i is better.
|
|
|
|
STATUS: Under investigation, postponed until after
|
|
libpng-2.0.0. About 160 loops will be turned around
|
|
in libpng-2.0.x betaxx, for testing.
|
|
|
|
3. July 4, 1998 -- ENHANCEMENT -- Glenn R-P
|
|
|
|
libpng-1.0.5 and earlier transform colors to gamma=1.0 space for
|
|
merging with background, and then back to the image's gamma. The
|
|
bit_depth of the intermediate (gamma=1.0) representation is probably
|
|
not sufficient. In the typical gamma=1/2.2 situation, the linear
|
|
pixels need about 4 more bits than the gamma-encoded ones, to avoid
|
|
loss of precision. A similar situation exists with the rgb_to_gray
|
|
operation.
|
|
|
|
STATUS: under development.
|
|
|
|
4. September 1999 -- ENHANCEMENT --
|
|
|
|
It should be possible to use libpng without floating-point aritmetic.
|
|
|
|
STATUS: Under investigation, implementation postponed until after
|
|
libpng-2.0.0.
|
|
|
|
Much of this was completed in libpng-1.0.6, but gamma compensation
|
|
is not yet done in fixed-point arithmetic.
|
|
|