Re: PSP5 finding the best compression for a .jpg

by "MomJ" <momj(at)mindless.com>

 Date:  Sun, 11 Apr 1999 16:20:10 -0400
 To:  "Aidan Whitehall" <aidan(at)netprofits.freeserve.co.uk>,
<hwg-graphics(at)hwg.org>
  todo: View Thread, Original
Hello again Aidan and all,

As for the previous question about GIF colors and compression, some people
may find some of the info on my ZDU pages helpful. Particularly
http://www.capecodmouse.com/moushold/psp/zdu/4class.html about transparency
and GIF files.  Or http://www.capecodmouse.com/moushold/psp/zdu/1class.html
Anti-aliasing & File Types. (These pages are graphics intensive and take a
minute or 2 to load.  While this is not good web design, it is necessary to
use "bad" graphics in illustrating the concepts.)

Now onto the JPG question.

There is Smart Saver put out by ULead to work with compression. It gives you
a view of the effects of compression before you save the image. But this is
still an image processor view and not a browser view. The only real benefits
I see in smart saver are the ability to make more than one of your colors
(shades/tones) transparent in a GIF, and the batch conversion provides a few
more options.

Also Irfan View  http://stud1.tuwien.ac.at/~e9227474/ has a nice little
batch conversion too. Be sure to check out the advanced options in batch
conversions!  This is a great little viewer and performs excellent for quick
touchups.  Uses a minimum of system resources AND it is free!!!!

However I continue to use PSP in much the same way as you outline.  I have
annotated your steps below, eliminating a few.  I find the file sizes and
quality between the 2 programs (smart saver and psp) much the same.  In
other words, if you have learned and are comfortable with PSP then continue
using it.


1) Open up your image with File | Open

2) Select File | Save COPY As (*this will NOT change the working image!)
3) From the "Save as type" drop down box, select "JPEG - JFIF Compliant
(*.jpg; *.jif; *.jpeg)" (this will stay set to the last used type in save
COPY as)
    3a) Click the "Options" button
    3b) Use the slider (or type in the value) to set the compression to 15%
    3c) Make sure the "encoding" is set to "Standard" (unless you want a
.jpg that "fades" in like an interlace-.gif, but this can result in bigger
file sizes, someone said)
    3d) Select "OK"
4) Type in a filename (I use "Filename15", to indicate it's had 15%
compression)
5) Repeat steps 2-3-4 for VARIOUS OTHER COMPRESSIONS (30, 45% etc
compression, altering the filenames appropriately)
6) Open your saved files in your web browser(s) to compare the quality of
the displayed images.  (If they are small enough in dimmension you could
even make a quick test page to view them side by side. A quick drag n drop
in Homesite does the trick!)
    I prefer this method as each browser handles colors a little differently
than image editors. Now you can see what will be presented to your viewers.
    To facilitate this I have added an action for GIF and JPG (in file
types) called "browser ie" and "browser ns".
    Therefore, for this step I simply open windows explorer and right click
on the file names to view the images in the browsers.

7) Decide which .jpg has the best compromise of compression versus image
quality - ie, you want as much compression as possible, but not so much that
the image looks awful.
8) Delete those you're not going to use


Can you tell I really rather being playing with PSP and all my other fun
stuff than finishing my *spring cleaning*?

Mousily yours,
MomJ - the mouse with the 5 foot tail!
(aka CCmouse)
Visit the Mousehold http://www.capecodmouse.com/
Home of MOUSEHOLD CREATIONS
ICQ#:  6522423
AOL IM:  MomJmouse (seldom on this service)

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