In order to save hard-drive disk space I want/need to start compressing my Photoshop files. The Tiff-LZW or Tiff-ZIP compressions seems like a great lossless format alternative with apparent significant compression. Is anyone aware whether there is truly no loss of file information with these formats, or does some minimal degradation occur? Any thoughts on JPEG2000 lossless compression?
#1
Is anyone aware whether there is truly no loss of file information with these formats
loss-less compression means "no loss". :)
#2
Be aware that LZW compression typically won't save space if the file is a photographic image at 16 bits per channel, and may even increase the file size. 8 bpc photos compress well, though. Not sure about ZIP compression.
#3
Michael,
the compression ratio for 24 bit RGB TIFF images by ZIP
isn't impressive - about 2..3 according to older tests.
An actual test for a color portrait with a larger uniform background delivers ratio 4.
IMO, all flavours of TIFF are correctly handled by Adobe programs, but for the sake of clarity I'm saving TIFFs
(with or without layers) uncompressed, and the compression is applied if necessary for PDFs (InDesign).
Best regards --Gernot Hoffmann
#4
all flavours of TIFF are correctly handled by Adobe programs
Photoshop only handles a subset of TIFF codecs.
#5
I seem to recall that it doesn't open TIFF files with PackBits compression.
#6