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Use uncompressed TIFs to speed iPhoto
Authored by: mweissen on May 15, '03 02:04:20PM
This hint is highly dubious, verging on amusing. Some comments:
  • iPhoto uses small 20kB JPG thumbnails for all previewing purposes.
  • Converting JPEG files to uncompressed TIFFs requires ten times the disk space and does not make the quality any better.
  • A G4/600 should be able to load and decompress a JPEG image faster than the corresponding TIFF can be loaded from disk.
  • If you really cared about image quality, you'd be working on your TIFF files in PhotoShop instead of iPhoto anyway!


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Use uncompressed TIFs to speed iPhoto
Authored by: dave1212 on May 16, '03 12:31:45AM
* Converting JPEG files to uncompressed TIFFs requires ten times the disk space and does not make the quality any better.

I don't believe that was the plan. To capture the pictures from your camera in RAW would be best, and to then save to uncompressed TIFF. But you're right, JPEG->TIFF does nothing but chew up space.

* If you really cared about image quality, you'd be working on your TIFF files in PhotoShop instead of iPhoto anyway!

Not if you don't have the money and don't want to pirate.

As well, iPhoto is an Image Cataloging Application, Photoshop (even with the File Browser) is not.

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Use uncompressed TIFs to speed iPhoto
Authored by: danvtim on May 16, '03 11:13:55AM

"iPhoto uses small 20kB JPG thumbnails for all previewing purposes. Converting JPEG files to uncompressed TIFFs requires ten times the disk space and does not make the quality any better"

I never said that converting from JPG to TIF would improve quality. I convert them to TIFs because the write times for TIFs on my camera are too slow for most situations. So, I shoot them in fine JPG and than convert them to TIFs for editing so there is no further loss.

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.


"If you really cared about image quality, you'd be working on your TIFF files in PhotoShop instead of iPhoto anyway!"

I do use Photoshop. I use iViewMedia Pro and was thinking of moving to iPhoto for organizing not editing.



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re: Use uncompressed TIFs to speed iPhoto
Authored by: mclbruce on May 16, '03 12:33:58PM

Thanks for submitting this hint. Have you tried automating the convert and import procedure with AppleScript? It would be nice to just drop a bunch of images on an icon and have them imported into iPhoto as TIFFs.

One of the great things about using TIFFs in iPhoto is you don't have to worry about the image quality degrading over multiple edits and saves, as will happen with JPEG files.

Your post received 8 replies, plus your own reply, so far. Apparently none of the other posters did any testing with different file types in iPhoto. That's sad. I wouldn't want this site to change from "Mac OS X Hints" to "Mac OS X Opinions." Hints have much more value to me.



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re: Use uncompressed TIFs to speed iPhoto
Authored by: danvtim on May 16, '03 03:59:15PM

It is interesting to note that they commented and said it's wrong without any real testing as you said. You may want to point out the the owner of this site your observations about the comments of others.

I would be interested in seeing if others get the same results as I did. I will do some more testing to see if it acts the same with photoshop documents.

I don't really know that much about Applescript and I have photoshop and use a simple action to save as an uncompressed TIFF which is easy to create. If you don't have Photoshop you should really consider buying Adobe elements which basically is all the features from photoshop that one needs for photo editing for $90. It's a steal at $90.



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re: Use uncompressed TIFs to speed iPhoto
Authored by: mweissen on May 19, '03 06:20:46AM

It is interesting to note that they commented and said it's wrong without any real testing as you said. You may want to point out the the owner of this site your observations about the comments of others.

Anything you say, online or otherwise, may be met with commentary and/or criticism. It's part of human interaction and communication. I don't know who is going to complain to whom about what, but surely you realize that the ability to comment and discuss is what keeps people coming back to this site? Do you want to censor all feedback, or only negative feedback? Does this apply to all hints, or only those submitted by you? Post one negative comment and be banished forever? Tough...

It's easier to flame people semi-anonymously on the Internet, though. Sometimes you just don't think far enough before you press the Send button. I'm sorry if my fr1st p0st seemed obnoxious, it wasn't intended that way. I should also have posted my informal (infernal?) benchmarks straight away, instead of letting you assume that I was speaking out of my hat. (Sorry. My loss.)

In my opinion, the real value of the hint is that iPhoto can handle other formats than JPEG, which is interesting and something I can see myself making use of. I'm not really interested in seeing whether iPhoto is 13.7% faster or 16.2% slower when using uncompressed TIFFs. In my experience, TIFFs are slower than JPEGs, and I have attributed this to various technical reasons and backed up the claim using numbers in an earlier post today. The difference (around 15% on my TiBook) is not great and entirely within the margin of error. Laptops have slower disks anyway, and it's possible that your system with it's shining new 10 kRPM 250MB disks is a bit faster in that department. OK?

I'm however criticizing the way the hint is presented as gospel to all iPhoto users: Do you think iPhoto is slow? Then convert your library and feel the speedup! The hint is written as if it is intended for Mom-and-Pop iPhoto users. But when you drill down to the crux of the matter, you find that those who really could benefit from the hint are those semi-professional photographers with enough money to buy a decent camera rig, but not enough to buy a recent Mac, yet just enough to buy a few big hard disks.

The hint says that "you should convert your photos to TIFs for editing and printing", but this is true only for certain meanings of "editing and printing". If you're a photo pro, then yes, nothing beats TIFF (or RAW). Uncompressed TIFFs take a little more space than compressed TIFFs (from 14MB to something over 20MB) and are faster to use, no problem there. Small price, big gain. But most iPhoto users couldn't tell a JPEG from a TIFF if it bit them in the arse (sorry, couldn't find any statistics here either) and for them, "editing" means changing the contrast using iPhoto. For these people, converting their library is a waste of time and disk space. The file sizes go from 2.2MB to over 20MB, and it isn't worth it for one lousy contrast change.

The last paragraph is the killer: "you can use iPhoto itself to convert the files [...] if you don't have Photoshop". If you don't have Photoshop or MacGimp or any other heavy-duty image editing application, it is probable that you do not care enough about image quality to benefit from this hint. Am I right? Those who are interested in getting good quality prints get the tools for the job. Photoshop is one such tool, MacGimp another. iPhoto caters to another segment (although the cataloging feature may be useful for pros too).

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re: Use uncompressed TIFs to speed iPhoto
Authored by: danvtim on May 19, '03 11:58:03AM

I just gave my observations. If it does not work for you than state that it did not work and show why. As I said before, try it for yourself. If it works for you, then great. If it does not, than do not use it.

The other poster was the one who pointed out that you were stating opinion and did not show any measurable tests which he believes runs counter to the purpose of this site.



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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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