Exercises - MC
- Compare compressed vs. uncompressed sound
- Compare compressed vs. uncompressed image
- Compare compressed vs. uncompressed video
- Look over routines for JPEG compression.
and tell the instructor the line numbers where zig-zag encoding coefficients
and also the line numbers where DCT quantization coefficients are given
in routine jddctmgr.c.
Hint: each of these looks like a table of numbers. If you prefer, just paste
the relevant lines into your message instead of counting lines.
- On video.cs.vt.edu take a look at the files in ~fox/jpeg
- Read over how to compress a file using
"man -M /export/home/fox/man cjpeg"
and how to decompress a file using
"man -M /export/home/fox/man djpeg".
Then you can run those routines on some image files like testout.ppm
in ~fox/jpeg and put the output in your own directory so you can use
to display it. If you prefer, instead of using "xv" you can FTP
the output files to your diskette in the lab and view them there. Probably
the easiest approach is:
- Make sure in your home directory you have directory
if not you can say
- Run cjepg by first doing
cd ~fox/jpeg and then
cjpeg -quality 25 ~fox/jpeg/testout.ppm > ~/public_html/testout25.jpg
- Use Netscape to view that file by opening the URL
where your login ID replaces "name" above
- Send the instructor brief comments on the visual quality of files
produced by cjpeg with various parameter settings.
- Describe for the instructor Storyspace,
WWW in terms of the Dexter and Amsterdam
models. In particular, discuss:
- if and how composite nodes are structured,
- if links can have multiple destinations,
- if links are birectional,
- if links can point into locations inside nodes,
- what multimedia linking support is provided,
- any special presentation capabilities,
- any other special capabilities.
- OPTIONAL (worth 2 points for a good job): Look
over the QuickTime programs (*.c)
in the Derring Assignments/CS4624/MIS_QuickTime/For Programmers
folder (e.g., in subfolders
OneShot, QuickTrivia) in the Derring Lab and comment briefly
what the purpose is of 2 of the C routines included.
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Copyright 1996 Edward A. Fox