Graphic Underworld pg 7: Production Graphics with Wendy Peck at webreference.com

Graphic Underworld: Image Optimizer

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.

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.

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).

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.

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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Graphic Underworld Tutorial Index

Graphic Underworld Start
Vector vs Raster
Vector to Raster for the Web
Vector/Raster When and Why?
Optimize is Not Passé
How Compression Works
Image Optimizer