Best program to batch compress JPGs with minimal loss?

Question

My photo catalog is getting bigger and bigger. It's mainly my fault because in my noob years I used to export all JPGs with a 100% quality, point at which files can reach the 10mb mark or even more. I still do, I don't know why :F

Right now I'm at 600gb and I good chunk of it is because I keep RAW files, but JPGs are quite large and could be reduced.

What software do you use to batch compress files? I'm looking for a maximum quality solution -I know there's no lossless in JPG, but what is the least lossy one, in terms of quality.

So far I found https://imageoptim.com/ which unfortunately it's a Mac only solution. I tried ImageMagik also but I can't manage to get the correct settings, mainly because is command line based.

Answer 1

JPEGmini. It's $20 for the full version, but you can trial it (as a test of quality) for free. The trial version (or, rather, the unactivated version) has a 20-image-per-day cap — no time bomb, though, so someone with different needs may never have to pay for it. The full version can recompress entire directories at a go.

It'll take most large high-quality JPEGS down to 20-25% of their file size (some more, some less) and you really need to do an image subtraction to see that it's made any change to the actual image at all. ("Large" means up to 28MP; if you've got a D800/D810/α7R or a medium-format camera and have left the JPEGs at your camera's full resolution, you'd have to spring for the "pro" version, and I'm not sure it's still cost-effective at the "pro" price.) It'll also do a batch resize at the same time if you want to do that.

It's slow as the proverbial molasses in January to load (it's a .NET application, and sort of feels like loading a full-featured Eclipse-based IDE), but it runs at an acceptable pace once it has finally loaded. (The "pro" version is considerably faster, but see the price issue mentioned above. Nothing's ever fast enough when you're doing a big job, but once the big job is over, you're left wondering why there's a Veyron in the driveway when all you use it for now is to go to the corner store for milk a couple of times a week.)

But do trial it on a few images before you buy — even cheap is expensive if it doesn't do what you want. The opinions of random weirdos on teh intarwebz ar often worth less than you paid for them. Oh, one more thing: the license fulfillment is done through B&H, so it's not instant. (Someone at B&H, lovingly known through the ages as "Kosher Kamera", has to press a button or something to make sure that you can't get it on Sabbath or a no-work-allowed holiday accidentally. Weird choice for a sole retailer of an electronically-delivered product in my opinion, but it's the choice they made.)

(No affiliation, just an otherwise satisfied customer who really wonders about the B&H part.)

Answer 2

If you are not afraid of using the command line, ImageMagick is the tool you need. It is the state of the art of image processing and it is widely recognized as THE software for image processing.

In your specific case, you are interested in changing what ImageMagick refers to -quality value. Since a similar question has already been asked here I will just cover the needed adaptations for your specific question.

dir -recurse -include *.jpg | %{convert  $_.FullName -quality 80 "C:\processed\$_"}

Where you need to substitute the quality value (in this example 80) to your preferred compression level and the output directory C:\processed\ to suit your needs.

This method will essentially duplicate all your photos (even though compressed) to the specified path. In the case that you do not have enough disk space for such operation, you can use the mogrify command that will overwrite everything that is present in the output path with the same filename. Be aware that it is a dangerous operation because there is no going back and if you ever need to perform such action it is better to first try it on a dozen backupped photos and once ensured that the output is as desired you can safely run it over your catalog.

So if you mogrify some photos (with the output path specified) and you are not happy with the result you can safely re-run the command with a different quality value and the photos in the output directory will be overwritten.

I'm available to elaborate more on mogrify if needed but basically, you just need to swap the convert.

Answer 3

Photoshop will certainly do this, and quite well.

You can easily achieve it by saving an action with the steps you desire and can even save it as a droplet that to be used on demand very easily.

This has more information on Photoshops capabilities in this area: http://helpx.adobe.com/photoshop/using/processing-batch-files.html