Sunday, January 2, 2011

Tip Sheet #8 - Save Big Files Fast

Saving big files in PhotoShop® can take time, even if you have a fast computer. Usually I don't mind... its 'mandatory' time off for daydreaming, the Zen of giclée. As my own illustrations are mastered between 20,000 and 30,000 pixels on the long dimension, I spend a lot of time day dreaming. But other times long saves can be annoying.

Frequently I am saving in the PhotoShop® Large Document Format (.psb) when the file size exceeds 2 gigabytes. But it that takes time too, especially when you save to multiple locations, which is our policy, for safety's sake, at Vashon Island Imaging.

Cutting Down Save Time

Most pictures are built in stages... you work on a background, add some foreground, etc.... saving as you go. Saving a big file can take several minutes for each save. Time is money, eh?

A big chunk of the save time is the generation of a full resolution composite, which is a fully bit-mapped version of the picture you are saving. Scaled down versions of the master composite image become the smaller thumbnails used for previews, etc.

If you don't need to see any of those -- and for those intermediate stages of image production and 'just for safety' work-flow saves you usually don't -- you can save the compositing time by turning the picture off before saving it... Huh?

Full Resolution Composite... of Nothing

PhotoShop® pictures are built in layers... each layer has a part of the picture. A composite is all those layers merged together. When you merge layers or flatten an image, you are making a composite. When PhotoShop® saves an image it makes a composite of it first, as part of the saving process. When images are very large, making a composite takes most of the saving time. If only there were a way to bypass that, eh? There is...

You've heard of a 'work around'? ...Here's a 'save around':

Before saving turn off all picture layers and turn on one transparent layer. There should be nothing in the picture area when you save.

Since you can't see the picture, and either can PhotoShop®. Since there's nothing there, a full resolution composite takes no time at all.

Eventually, you will want to be able to see previews of your saved pictures. Save those with the picture layers turned on again.

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