Sue, a San Diego friend, sent me the following e-mail:

Hello Dee -

Just wanted to pass on trivia about images.

Looked up your web page - I've seen it before but never connected the pics with the person - very nice web site, but who is the nice looking girl in all the pics???

Noted on your front (web) page the GIF vs JPG image size.

Apparently when editing, often images not using a proprietary image format use TIFF, as the image is virtually loss less when editing or resizing.

The TIFF, when zipped, will compress noticeably, so when uncompressed, expands likewise noticeably.

The GIF format is another which compresses / decompresses noticeably when zipped, and unfortunately, is best used with only two colors or less; exceeding that color count drastically increases GIF file size.

To feel "good", take a GIF image with a high color count, zip it and compare file sizes - the compression level will seem impressive; the same is the case with TIFF files (TIF).

Then to feel "bad", take a JPG image, zip it and notice the near or at zero compression factor. That is why I invariably use images in the JPG format.

Sweet dreams

Sue xxx

My experience completely supports Sue's comments, and it is sometimes exasperating to watch a relatively small graphic take significant download time, and it can be a problem if your site ISP storage limits are restrictive.

My digital camera takes 3MPixel photos, and in a JPEG format with the camera's own compression, these pictures take about 1Mbyte, on average. They tend to vary from 0.5Mbyte to 1.2 Mbyte, with pictures of clouds in the sky over a snowy field (not many details) taking less, and a closeup of the forest where you can see the trees and branches (more details) takes more.

After you've loaded the pictures into your computer, experiment with the picture software that came with your camera or scanner -- you don't need to be an Adobe PhotoShop whiz kid for this.

Things you can do with the pictures:

• Crop them to remove extraneous background
• Adjust the brightness and contrast, especially if the picture was back-lit
• Decide the size (in pixels) you want the saved picture to be. Remember that most displays are about 72 pixels per inch, with only very high grade displays in the 100 pixels per inch range, so a picture that is 720 pixels wide will usually display about 10 inches wide.

  For most Internet purposes, 4-6 inches, or somewhere around 360 pixels wide should be quite adequate.

  If you want to have a larger, more detailed picture available for viewing, make a link to bring it up after showing the smaller version.

• After you've chosen the finished size of this picture, choose JPEG format -- there will be an option that leads to compression choices. In the case of my camera software, it just asks about quality. Try the different options...
  1. Leave the basic cropped and adjusted picture, and its finished size alone
  2. Start with one end of the range of "quality" or "compression" choices, and save the picture with some name that indicates its setting (e.g. MYPIC-high.jpg)
  3. Save the picture several more times, with other quality or compression options, saving them similarly.
  4. Now just go back with your usual web browser (Netscape, of course, but I know some people use Internet Explorer), and examine the resulting pictures.

     I suspect you'll find that medium quality or compression saves a lot of disk space and hardly can be distinguished from the original. With too much compression, some of the fine details you want will begin to get lost. That means you want the next higher quality setting or less compressed setting.

• I have found that 75% compression or "Medium Quality" works OK for most of my pictures.
• Note well, that if the picture is smaller on your hard disk, it will be smaller on your web server's disk, and it will take less time for you to upload it and for others to download it as well.

As specific examples of this process, I took a single picture I was preparing, cropped it and otherwise adjusted it as I would prefer, and then saved it with four different JPEG compression levels, (Best, High, Medium, Low Quality) as provided by the my standard camera software.

Here's the result:

BraBest32.jpg -- 320x225 -- 55K	BraHigh32.jpg -- 320x225 -- 17K
Bra32.jpg -- 320x225 -- 13K	BraLow32.jpg -- 320x225 -- 11K

I cannot tell the difference on my display among these four pictures... Clearly there isn't much visible difference here, so why not use the picture with a lot less size. The "MEDIUM" version is the one I generally pick because it saves most of the space and bandwidth. Probably if I were a purist, I'd have chosen the "LOW" because it saves another 20%, more or less.

I hope this helps inspire you to be sensitive about the size (in KB) of your pictures, as lots of us still don't have the ability to get broadband connections.

If you have follow-up comments, questions or suggestions, use the e-mail link at the top of this page, please.