Embedding masks in workflows: TIFF compression

[tomczak]

Masks seem to be saved as uncompressed TIFFs when embedded in workflows. That makes workflow files considerably fatter (e.g. a 10Mp masks adds some 10Mb the workflow). Since masks are 8bit and usually contain large solid areas, they compress well and the saving speed penalty is small. Would it make sense to embed masks as LZW or ZIP compressed TIFFs?

p.s. Mask have DPI factor set to 100, regardless of the DPI of the parent image or default DPI set in preferences. It makes no difference when masks are used as masks, but sometimes mask is the final product and DPI tag may matter.

[tomczak]

Just another note in the same vein: the PWP's gray wedge 15 TIFF file is 1.1 Mb uncompressed (as distributed with the programme) and ~11kb saved as compressed TIFF.

[MikeG]

I don't save enough workflows to worry about the size of masks, but I was interested enough to see what the numbers are like.
I created a 4,000 x 3,000 pixel mask consisting of a splined shape with a 135 radius blur.
Then I simply saved the mask, firstly as an uncompressed tif, and as zip then LZW compressed tif, then as 100% jpeg and 95% jpeg. I reloaded the uncompressed tif file before each subsequent save.
The uncompressed tip was 11.7 MB, both the zip and LZW compressed tifs and the 100% jpeg were less than 0.4 MB, the 100% jpeg (slightly) the largest. The 95% jpeg the smallest at 0.222 MB.

Mike.