I looked into this issue a bit.
1. this was compiled into /usr/local, so there's no conflict with base anything.
2. it was compiled with --enable-static and --enable-shared, so base libjpeg.so.62.0.0 is not same (despite the same name) The compiled is 543 lines vs base 251 lines.
3. the compiled libjpeg.so.la clearly states where the compiled libs have to be located, in this case /usr/local/lib.
4. the compiled libs support jpeg functions not included in base. Briefly they include:
djpeg:
decompresses image files from JPEG/JFIF format to either PPM (PBMPLUS color format), PGM (PBMPLUS gray-scale format), BMP, or Targa format.
jpegtran:
is used for lossless transformation of JPEG files.
rdjpgcom:
displays text comments from within a JPEG file.wrjpgcom
wrjpgcom:
inserts text comments into a JPEG file.
5. On complaints about including docs,"bloat",etc. The docs in man1 are --help files, 4K a piece for each of the above commands.
When you type "djpeg --help", for example, it lists all the switches and usage:
usage: djpeg [switches] [inputfile]
Switches (names may be abbreviated):
-colors N Reduce image to no more than N colors
-fast Fast, low-quality processing
-grayscale Force grayscale output
-scale M/N Scale output image by fraction M/N, eg, 1/8
-bmp Select BMP output format (Windows style)
-gif Select GIF output format
-os2 Select BMP output format (OS/2 style)
-pnm Select PBMPLUS (PPM/PGM) output format (default)
-targa Select Targa output format
Switches for advanced users:
-dct int Use integer DCT method (default)
-dct fast Use fast integer DCT (less accurate)
-dct float Use floating-point DCT method
-dither fs Use F-S dithering (default)
-dither none Don't use dithering in quantization
-dither ordered Use ordered dither (medium speed, quality)
-map FILE Map to colors used in named image file
-nosmooth Don't use high-quality upsampling
-onepass Use 1-pass quantization (fast, low quality)
-maxmemory N Maximum memory to use (in kbytes)
-outfile name Specify name for output file
This package is from BLFS, and configured according to their recommendations. The descriptions are copied from the BLFS book. I have no problem with including/not including/removing the manuals/removing the libs/ etc, etc. The license is free...people can do whatever they like to suit their own purposes.
note: As noted above, I only submitted this because I was too stupid to grep the correct lib name, so thought it wasn't in base. I've got a growing directory full of these extensions for my own use....all with manuals, since I need all the help I can get