Squeezing Mac JPEGs
October 5, 2006 6:45 PM   Subscribe

How can my brother reduce JPG file size on his Mac, using only the provided software?

Long story medium: I have a family member with a Mac. He is emailing his digital photos, and it appears he is just using the default JPEG photo the camera is giving him. These are much larger than they need to be, and he's on a dialup connection in the boonies.

I'd like to give him instructions on an easy way to reduce the file size of his JPEGs without changing the physical photo size (ie, up his compression).

I need to do this using only the default apps that come with a Mac. I have no idea what comes with a Mac. For Windows, I would tell him to simply open the photo in Paint, and then re-save it as JPEG. Paint's default compression settings are pretty good, so this reduces his 2 meg files to 500K.

What do I need to tell him to do on his Mac? Remember: default software only, simple instructions. Thanks!
posted by Very Witty, Wilde! to Computers & Internet (12 answers total) 1 user marked this as a favorite
Best answer: Tested in the latest version of OS X:
Open the JPEG in Preview.
Choose File->Save As...
Make sure the format is JPEG.
Move the Quality slider closer to Least.
Click Save.
posted by aneel at 6:55 PM on October 5, 2006

Are you sure you only want to increase the compression? That will make the pictures look worse, but not make the files smaller nearly as well as resizing them to a reasonable size does. If they're just for viewing on screen, you want to resize them.

However, if you are sure, tell him to open the files in Preview (probably the default, it's in Applications) and choose Save As... from the File menu. Give it a new filename. Then, move the Quality slider all the way to the left and click save. Done.

Otherwise, if he's using the built-in Mail app to email, tell him to attach the pictures to an email, then choose the smaller sizes from the pop-up at the bottom of the compose window.

Best yet: use iPhoto, and click on the photos to be sent. Choose "Export..." from the file menu.
Change the pop-up that reads "original" to "JPEG" and click "Scale images no larger than", and type 1200 in the width box. C
lick export.
posted by bonaldi at 7:02 PM on October 5, 2006

Imagewell Free. Easy. You can specify size in pixels or in K. Very Drag and drop.
posted by filmgeek at 7:07 PM on October 5, 2006

Upload to flickr. View all sizes.
posted by croutonsupafreak at 7:40 PM on October 5, 2006

Some versions of the Mac computers come pre-loaded with iPhoto. If iPhoto is available, then he can select the photos he wants to send in iPhoto and simply click the email icon. A box will pop up asking which size to send the photos as (small, medium, large, full size). The photos will then automatically be attached in the appropriate size in a new email message.

If iPhoto isn't available, then try the Preview method mentioned above.
posted by jefbla at 8:47 PM on October 5, 2006

Is he on MacOS X 10.4? If so, Apple's mail client 'Mail' has an option to resize image attachments. It's a popup menu in the lower right hand corner of the compose window.
posted by nathan_teske at 8:53 PM on October 5, 2006

Response by poster: Thanks everybody for these answers. I'll work with him and see what we can do.

(aneel gets best answer because he stayed within the lines - change compression/quality, NOT resize photo, software must be installed by default)
posted by Very Witty, Wilde! at 10:58 PM on October 5, 2006

(aneel gets best answer because he stayed within the lines - change compression/quality, NOT resize photo, software must be installed by default)

Eh wot!? So did I! But I offered bonus points in case you were mistaken about the size they have to be. Because you must be: if they're for viewing on screen, they don't have to be any larger than the screen -- 1200x1000 say; if they're for print, you'll make them look like hell by upping the compression that high.
posted by bonaldi at 3:11 AM on October 6, 2006

Use iPhoto and use the send mail-button. that will let you choose the size of the picture and open a mail to let you send it.
posted by KimG at 7:49 AM on October 6, 2006

If you're just looking for a quick re-size use SnipShot a very snazzy Web 2.0 online photo editing tool.
posted by xpermanentx at 8:15 AM on October 6, 2006

Does this guy even have Mac OS X? Important detail to have. :-)
posted by drstein at 12:32 PM on October 6, 2006

Response by poster: Thanks again, everybody. He has OS X, but I'm not sure which variant yet. It's unlikely he's gone up to 10.4, so he most likely has an updated 10.3.

I'm sticking with "same photo dimensions, smaller file size" for now, since that definitely works for me. My "Paint" routine drops the file size by 3/4, and I can't see any difference in the quality of the image. I suspect he's using a "superfine" quality setting on his camera, so the JPEG he's getting is probably not compressed at all.

I'll ask him if he wants to keep the same photo dimensions, which currently work well given that they exceed the screen real estate of most of his recipients (the rest of my family), meaning that their viewer always has an opportunity to show a full screen picture, and allows for zooming in on details.
posted by Very Witty, Wilde! at 3:01 PM on October 6, 2006

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