| |
| Known bugs and suggested enhancements in libpng-1.0.8 |
| |
| 1: November 28, 2000 -- BUG -- buffer overflow in png_chunk_warning |
| |
| A buffer overflow occurs in png_chunk_warning() because 16 bytes |
| are allocated for "[nn][nn][nn][nn]" which requires 18 bytes. |
| |
| Status: Fixed in libpng-1.0.9beta4 |
| |
| 2: 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 |
| |
| 3. 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); |
| |
| 4. 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). |
| |
| 5. 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. |
| |
| 6. 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. |
| |
| 7. 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. |
| |
