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Use uncompressed TIFs to speed iPhoto
Authored by: mweissen on May 19, '03 02:56:17AM

Also, iPhoto does use jpg for the thumbnails and not TIFs for scaling so logically they should perform the same yet because of TIFs are faster there must be more going on behind the scenes other than scaling. This is of course the crux of the matter.

"A G4/600 should be able to load and decompress a JPEG image faster than the corresponding TIFF can be loaded from disk"

This is my point. One would think that the I/O time would be greater than the overhead time to decompress; yet on my system it?s clearly not the case. Try it yourself with a few hundred JPGs in one album and the same photos converted to TIIF. Let us know what you find.

I used the following two commands in Terminal (bash). The djpeg binary comes from the Fink package libjpeg-bin. The data set was 50 JPEG files totaling 40MB, and a 360MB disk image (OS X 10.2 install disc 2, actually). In both cases, the data comes straight from disk (not memory cache).

time for i in *.JPG; do djpeg $i > /dev/null; done
time cat foo.dmg > /dev/null

My stock TiBook 667/30GB can decode the JPEGs in 19 seconds wall clock time; reading the disk image takes around 23 seconds. These values are fairly consistent with other benchmarks I've seen (just search for +jpeg +library +benchmark on google).

What does this prove? Nothing much. The difference is small and could be zero on a windy day. The stock 30GB IDE hard disk found in a TiBook is not the fastest, but reading one 360MB file is faster than reading 50 files of 7,5MB each. The djpeg library is not optimized for the G4, and as a side effect the photos are converted to PPM (which I'm not really interested in measuring).

It's good that you have found a way to subjectively speed up iPhoto. Your system apparently has fast disks, and since TIFF is your format of choice anyway, it seem like a smart choice to use TIFFs in iPhoto -- for you. There are lots of questions that affect this decision, and all answers have to be "yes" before this hint is of any use:

  1. Do you repeatedly open, edit and save all of your photos?
  2. Have you got oodles of disk space?
  3. Have you got a slow Mac?
  4. Do you do pro-level printing that requires TIFF quality?
Case in point: my father fails on all questions except possibly number 3. Even so, he does "editing and printing" of his photos (read: experimenting with brightness, contrast and color balance, then printing the photos on a cheap bubblejet) and thinks iPhoto is dog slow. The last thing I want is for him to read this hint and to start saving his photos as uncompressed TIFF, or worse: batch converting his entire library.

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Use uncompressed TIFs to speed iPhoto
Authored by: danvtim on May 19, '03 11:08:01PM

You really seem to lack an understanding of the point of the hint. It's to suggest that using uncompressed TIFs rather that compressed ones is faster under iPhoto. If I switch from one uncompressed TIF album and then select edit do the same for compressed TIFs, I average 5 seconds vs. 10 seconds. I did assume that the user was at a level above that of your dad's level.



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Use uncompressed TIFs to speed iPhoto
Authored by: mweissen on May 21, '03 06:47:47AM
You really seem to lack an understanding of the point of the hint. It's to suggest that using uncompressed TIFs rather that compressed ones is faster under iPhoto. If I switch from one uncompressed TIF album and then select edit do the same for compressed TIFs, I average 5 seconds vs. 10 seconds. I did assume that the user was at a level above that of your dad's level.

You yourself may know what you want to write, but readers can only see the resulting text, not your thoughts. Here's an example of how the hint could have been written to avoid ambiguities:

"As a professional graphics artist, I'm interested in using iPhoto as a cataloging tool for my images while preserving the image quality. I've been using compressed TIFFs and, while I liked the iPhoto workflow, I always thought that the application was slow and useless. Then I tried uncompressing my TIFFs and -- lo and behold! -- iPhoto is now twice as fast! Opening an album of uncompressed files takes five seconds, versus ten for a compressed album! Kids, please try this at home!"



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