Re: photos in the directory

[Russ Wright <[e-mail]>]

I don't want to start a big JPEG debate right now, but here goes.

I just did a few quick tests on my Sparc II:

640x480 image
9 seconds to display JPEG photo in XV
4 seconds for GIF

207 x 237:
Display JPEG = 4 seconds
Display GIF = < 2 seconds

Yes, JPEG takes some time to decompress, but I can live with double the 
display time.

The real issue is image file size:

640x480 image
GIF = 133K
JPEG = 13K

This is a major consideration.  Consider a Macintosh that gets the photo 
over a 230.4Kbit localtalk link.  Smaller is better.  It takes about 15 
seconds to decompress and display the 207x237 image on my Mac IIfx.

The bottom line is that you should create small photos (100x100 would be 
nice) if you want people to look at them.


Now for your questions:

> For the demonstration he had a particular picture JPEG'd and at 1024x768 
pixels.
> To display this with xv (recent version) took >30 seconds, and the 
command

That is a BIG photo.  You do not want to put that photo in the directory.

How long did it take to display the photo in GIF format?  My guess would 
be >15 seconds.

> Q: What options are there in storing a picture?  Only in 24?  Other 
resolutions?

You can set the "quality level", which determins how much the image is 
compressed.  The more compression, the more information is lost in the 
image and the smaller the size. 

> 
> Q: What purpose is the photo stuff to serve?  Is it to store a persons 
picture

Any color or grey scale image.  Black and White should use G3Fax.

If you have more questions, read the documentation that comes with the 
jpeg software first.  (ftp.uu.net in graphics/jpeg - I think).


Russ