Photo Quality

Out of all the ways to save space in our photo gallery, it looks like the greatest and most obvious savings will come from using increased levels of JPEG compression.

We already reduce our photos to a pixel dimension of 640×480, both to save disk space and screen real estate. But that reduction alone is not enough.

Currently, the photos that iPhoto exports are close to 100% JPEG quality, which entails a very minimal amount of compression. On the up-side, this produces very good looking, sharp images. On the down-side, this takes up a relatively large amount of space.

So, I can easily use a program called ***ImageMagick|http://www.imagemagick.org/*** to batch-convert the files in our gallery to use higher levels of JPEG compression. This will result in photos which look slightly less sharp, but which take up dramatically less space on the server.

The real issue is: what level of compression is acceptable?

To that end, I have whipped up a very quick page of comparison which I would like all of our readers to take a look at:

***Three Guys Photo Comparison|http://prwdot.org/3guys.html***

The photo is a pic of Me, Bob, and Jeremy, and I have it shown at compression levels all the way from the original down to 5% quality. I also have notes on the side to indicate the size of the file, the quality level, and the percentage of space saved.

Let us know via the comments what you think the cutoff point should be as far as when the photos are no longer pleasing to view. There are a few obvious conclusions you can come to based on the rate of change in savings percentage, but I’d like to hear what everyone thinks.

Thanks!

Update: I’ve created a couple other samples for you to take a look at:

***Becky Photo Test|http://prwdot.org/becky-pic.html***
***Colors Photo Test|http://prwdot.org/colors.html***

These should give you a better idea of how the compression level varies based on the actual content of the photos. Images with more colors tend to compress less, where images with few colors compress a lot more.

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