Filed under: Software, Tips and tricks, Graphic Design
Making the most of Preview.app for image editing
Inspired by Bear Grylls's (of Discovery's Man vs. Wild) "make the most out of your situation" scenarios, I present you with a tutorial for making the most out of Preview.app. While not as powerful as graphics editing powerhouse Adobe Photoshop, Preview can oftentimes get you from Point A to Point B -- and sometimes quicker too.
Like Bear Grylls, you'll need to parachute out of a plane and into the house of a friend who doesn't have Photoshop -- just kidding.
First, a little bit of background. Preview comes pre-installed on Mac OS X, and it's the default image viewer on the system. For PC-to-Mac converts, you could think of it as the Microsoft Paint of OS X; except that it can do a whole lot more. Besides the ability to open a host of image file formats (JPG, BMP, GIF, among them, and even PSD and AI files), Preview can also open PDF files natively. I actually prefer it over Adobe Acrobat for opening PDFs, as I find that they open much quicker using Preview. And like Adobe Reader, Preview contains advanced features, such as annotating.
To get started, let's open a JPEG file and do a basic crop. Here, I'll be cropping Kanye West out of this photo with Taylor Swift. To do this, I'm going to use the rectangular selection tool (though you can also use the elliptical or lasso selection tool if your job calls for it). Once you select the area you want to crop, you choose "crop" (or command-k) from the tools menu. But because I want to keep my original file unchanged, I'm going to create a new document by using the "New from Clipboard" option, which will result in my Taylor Swift crop opening in a another document.

But let's say I change my mind and, instead, want to horizontally flip Kanye West to the right side of the picture, and to put Taylor Swift on the left.

There, that looks a bit more like it.
Oh shoot. I just found out that the person I'm sending this photo to uses a certain type of LCD monitor that may display colors differently. Luckily, Preview can easily change the color profile of the image.

But this image would look much better if I could remove the background and just Taylor on stage by herself. After all, this is her moment, right? While the lasso and smart lasso provide means to do this, I've found that instant alpha can more often than not do it quicker, albeit a few touchups that may also be required.

Preview also has a host of other features, including the ability to scan, screenshot and annotate images. It should, in my opinion, win an an unsung hero award in the image editing app category.
(Hold on for a minute. Some guy just had the nerve to interrupt me. "Yo Sang. I'm really happy for you, I'm gonna let you finish, but Photoshop is one of the best image editing apps of all time!")
I guess I'll have to show some of Preview's other features later on.

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Reader Comments (Page 1 of 1)
vandil said 10:20AM on 9-17-2009
Preview still needs paint brush/drawing aspects of MS Paint. AppleWorks used to have something decent. Can't they pay an intern to port it?
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gittenlucky said 10:24AM on 9-17-2009
I agree with vindil. Preview should have some more basic editing stuff. I use pixelmator for that stuff if I need it though. It is like photoshop for beginners and is a lot cheaper.
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Adnium said 10:37AM on 9-17-2009
For PC-Mac converts, it's actually the equivalent of Microsoft Photo Editor.
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Mike said 10:40AM on 9-17-2009
With Snow Leopard, Preview finally supports PDF forms where you can fill out fields and print it off, making Adobe Reader for Mac extremely obsolete.
However also with Snow Leopard, the "Zoom to Fit" option now just restores actual size for images smaller than the window, rather than filling the entire window. Very annoying.
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Gazoobee said 10:48AM on 9-17-2009
I think you should have at least mentioned the colour correction capabilities of Preview which are really quite good, especially if you haven't upgraded to Snow Leopard. You can adjust exposures, contrast, tint, add sepia effects etc. and (until Snow Leopard took it out), adjust the white and black point as well.
There is also a handy "sharpness" filter, which is necessary because of something else you didn't mention which is that there is no control over the algorithm used for re-sizing. This means reducing an image in size often kind of blurs it and requires a nudge on the sharpness adjuster.
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TYO said 6:37AM on 9-22-2009
@Gazoobee
Snow Leopard did *not* remove the features you mentioned. They are all still there. See the menu "Tools - Adjust Color...".
Brad Ingarfield said 11:19AM on 9-17-2009
How do you scan using preview?
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hohum said 1:30PM on 9-20-2009
Leopard (and earlier, I suppose) it was 'File - Import Image…'
Snow Leopard it's 'File - Import from Scanner >'
bward74 said 12:03PM on 9-17-2009
Wow! After reading this article, I took another look at Preview and can't believe I never knew some of these options were there. I do have Pixelmator, which is great. But Preview is great in its own way too.
The only time I came upon a PDF issue with Preview was one that had a gradient tint in the background, but only when viewing it with Adobe. Preview just displayed it with one colour at the top, then directly going into the other colour below, without the gradient.
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Al B. It said 12:21PM on 9-17-2009
A really good and really useful article -- but please review the usage of the word "albeit"! (This goes double for your EDITORS...)
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KeynoteKen said 1:20PM on 9-17-2009
As an iWork user, one of the handiest ways I've found to use Preview is as a compositing tool. Lay out your shapes/images in the iWork app of your choice, copy, go to Preview, do command-n and there you have a PDF (with proper transparency) that you can drag and drop anywhere.
http://www.makentosh.com/tipsfromtheiceberg/Blog/Entries/2008/6/26_Just_Passin’_Thru.html
My biggest gripe, though, is that you can't export to PNG and keep the transparency as an Alpha channel :( You have to use another app to get around that.
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ObeytheFist said 1:31PM on 9-17-2009
Preview is also the BEST free PDF editor available on any platform. It even beats out most of the paid competition.
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Alvin Lai said 1:38PM on 9-17-2009
Cool tip on the color profile, but there wasn't much said about using Preview.app's annotation tools (drawing arrows, ellipses, caption text) for images.
Here's a video I made to illustrate how to annotate with Preview:
http://www.youtube.com/watch?v=wbtiEyJ4Hc0
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eruanna said 2:56PM on 9-17-2009
Alvin, you should update to Snow Leopard, and re-do that video. Preview's annotation functions have changed quite a bit.
Nlz said 4:49PM on 9-17-2009
An interesting little hidden feature I noticed is that you can change the menu items for the image resize dialog by modifying ~/Library/Preferences/com.apple.Preview.ImageSizingPresets.plist
E.g. if your common task is to size something to fit into the 100x100 pixel size of a LiveJournal icon, you can simply add a new string item to the list that says "100 x 100". Then, you could select any number of pictures in Preview's sidebar, select Tools->Adjust Size..., and pick your new size preset from the "Fit into" popup. Then simply hit OK, and all images will be sized down to fit into that rectangle, while preserving the aspect ratio.
Pretty neat!
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Tom von S. said 3:23PM on 9-17-2009
Is there any way to do an "export for the web" ala Photoshop/Acorn? Maybe an Applescript that can handle it?
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sodapop said 5:33PM on 9-17-2009
The only useful feature missing is a resize tool.
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mtooster said 6:45PM on 9-17-2009
Great function in preview is dragging pages between pdf's. You can actually drag and drop almost anything to anything preview can open.
Real time-saver for me! (and for recepienta of my mails with only one attachment instead of 20 :-)
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Arru said 7:03AM on 9-18-2009
There's a pro-am level image extraction feature buried in the selection tools menu. You can use either shape or color as base, and it's easy to fine-tune.
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Jon K said 7:49PM on 9-21-2009
Preview loses a key feature? In 10.5 Preview.app would allow me to stitch PDF's together, making two separate PDF files into one. I'm trying to do that with the 10.6 version of Preview, but it won't let me save it. Am I missing something?
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