1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
|
Known bugs and suggested enhancements in libpng-1.0.8
0: November 3, 2000 -- BUG -- incorrect iCCP chunk is written
The compression_type byte in the iCCP chunk written by libpng is
usually incorrect.
Status: Fixed in libpng-1.0.9beta1
1. October 12, 2000 -- BUG -- pngtest fails
The three WRITEFILE calls in pngtest.c are incorrect. They must be
changed to read
WRITEFILE((png_FILE_p)png_ptr->io_ptr, data, length, check);
WRITEFILE(io_ptr, near_data, length, check);
WRITEFILE(io_ptr, buf, written, err);
2. August 28, 2000 -- BUG -- pnggccrd.c
The interlacing() function has still not been fully converted and
will not compile under gcc-2.95.2; it is currently ifdef'ed out.
STATUS: Fixed in libpng-1.0.9. There were also bugs in pngvcrd.c
which have been fixed. The replacement files are available at the
PNG web site (http://www.libpng.org/pub/png).
3. 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.
4. 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.
5. September 1999 -- ENHANCEMENT --
It should be possible to use libpng without floating-point arithmetic.
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.
|
