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To put my work up on my website, I initially collected some images and converted them to progressive jpegs. But later I went in and added more. I now can't tell simply by file size which ones are progressive and which ones are not. Is there a specific property in the file info in Finder, Path Finder or Bridge that can tell me which ones are progressive?

Better still, can I do a search for only progressive jpg files?

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migrated from Apr 24 '13 at 19:55

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up vote 4 down vote accepted

I found a simple tool that tests whether a JPEG is progressive. However, you have to test them one by one. It's probably not as automated as you were looking for, but it might be interesting for someone else having the same issue.

It uses HTML5 new features and JS, so it should be cross platform.

The tool:


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Thanks. That works too. – yrg Apr 27 '13 at 4:54

The exiftool command line tool, which is free and open source software which available for Mac (as well as Linux and Windows), can easily identify progressive JPEG files. If you run exiftool *.jpg it will print out the metadata of every .jpg file in the current directory. You can use a more complicated exiftool command line to print out only the filenames of progressively-encoded files, like this::

$ exiftool -if '$EncodingProcess =~ /Progressive/' -p '$filename' *.jpg
    6 files failed condition
    5 image files read

If you want to look across multiple directories, it can do that too:

exiftool -if '$EncodingProcess =~ /Progressive/' -p '$directory/$filename' -ext jpg -r .

Just run the above command exactly as-is in the top-level directory below which all of your images are collected. Or, if you want, run it from anywhere, and replace the . at the end (which means "use this directory") with the full path to your files, like "/Users/yrg/Desktop/Photo Collection", making sure to include the " quote marks if you have a space in the name.

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Thanks. Any options for someone not comfortable with the command line? – yrg Apr 25 '13 at 14:52
@yrg There probably are, but I'm not aware of them. The nice thing about this particular tool, for someone not comfortable with the command line, is that while the parameters look kind of complicated, the one program handles it all, so no scripting is required. You can look up what each option I used means in the docs — or you can just cut and paste the lines I've given above. (While ExifTool can do things which are destructive to your images, these just read. I promise.) – mattdm Apr 25 '13 at 14:59

I really like the instructions here at using Brew to install imagemagick:

$ brew install imagemagick
$ identify -verbose file.jpg | grep Interlace

The output will be either of:

Interlace: JPEG
Interlace: None
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This should be the top answer. – Jeffrey Jose Aug 23 '14 at 21:20

You can also try this tiny online tool: Progressive JPEG checker. It allows one to check images by pasting a valid image url.

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