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I have never recommended software in this column. I have
deliberately stayed away from any preference statements and have not even
done reviews. However, when we talk about image optimization, I cannot
ignore the small program that has saved me millions of bytes, and at times,
allowed me to do things I could not have otherwise accomplished. The program
is called Image Optimizer, and is available from Xat.
The standard version, which will do more than most of you will ever need,
is $39 US. There is a 30 day, fully functional trial download offered
as well. Unfortunately, the program is only available for the PC platform.
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Regional compression areas offered by Image Optimizer.
Red areas are compressed to the maximum level, while clear areas are
minimally compressed.
In the samples above, the image at the left has had
regional compression applied to remove some of the compression from
trouble areas. These samples were taken from images that were nearly
identical in file size, but note the extra artifacts in the samples
on the right.
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The main reason for my love affair with this program is the regional
compression feature. If you are not using software that provides the
option to preview both GIF and JPG versions of an image (like Photoshop's
Save for Web feature), you will also appreciate the ability to test
each format for file size and quality on one screen. You can open JPG,
PNG, GIF, BMP and TIF files, and save as JPG, GIF or PNG format. But
most optimizers have this feature.
The regional compression is shown in the sample at the left. The image
is represented as a grayscale image, and red represents a fully compressed
area, with the clear areas (as in the face and legs area) for no compression.
This image was a tough one – caught between GIF and JPG features
with lots of solid color, but also plenty of shading. JPG won after
testing many combinations, but the file size was still high if the quality
was to remain. There were two problem areas that prevented me from increasing
the compression level – the girl's face, and her legs. Raising
the compression level added artifacts instantly to those two areas.
However, by specifying that the face and legs area was to receive no
compression, I was able to produce a reasonable file size, and while
I did have to make some quality compromise, it was much less than with
the nonspecific optimization. This image would have been about 5 k larger,
or nearly 20 k, to deliver the same quality. The file savings can be
even more dramatic at smaller image sizes.
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Regional compression used to shave nearly 4 k from
the images at the right.
JPG image exported from PaintShop Pro (7.16 k).
JPG image with regional compression used on text and
fine areas (5.50 k).
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With many images, you can skip the regional feature and simply allow
the program to compress the entire image. However, on large images,
images that combine text and texture or images with soft or blurred
areas, the savings can be significant.
Optimized without regional compression (12.6 k).
Compressed using regional compression as shown at the
left (8.70 k)
Photos by Tom Thomson Photography.
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You may not find that regional compression saves file size in every
case. In fact, as software programs have become better at both compressing
graphics for the Web and providing real time views as the compression
options change, I have used this feature less. However, for that tough
project, with many photos (where every byte can make a difference),
or images with large background areas, it is worth its weight in gold.
The program also offers direct scanning, cropping and resizing on the
same screen, batch processing, and has recently added Digimarc watermarking.
The professional version ($99 US) also offers levels adjustment, noise
reduction and color correction, which can also aid in reducing file
size with excellent quality. As I stated at the beginning though, most
will find that the standard version offers all you need at a very reasonable
cost.
Disclaimer: I have no association with Xat.com in any way. This
is just a reasonably priced program that has bailed me out of trouble,
or allowed me to push graphic limits many times. Download the demo and
give it a try.
Whatever method you use to make your images smaller, do not forget
us out here with our slow lines. A few bytes may not seem like much
when you are creating an image, or testing on a cable modem, but it
makes a world of difference to many of your visitors. That cannot be
ignored.
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