With Preview you can quickly create a new image file from your clipboard contents. On it’s own that might not be too enthralling, but this feature extends beyond Preview, meaning any image that you have copied from anywhere using Command+C will work as the source image to create a new image file. This includes images copied from all web browsers, other Mac apps, and even files in the Mac OS X Finder.

Once you have an image copied to the clipboard:

• Open Preview
• Hit Command+N to create a new image based on the clipboard (or access via the File menu as screenshot demonstrates)
• Save the File as usual in your preferred format

I use this frequently when saving images from the web since it cuts out any digging around in the Finder for a saved image file. Instead, I can just copy an image to my clipboard from Safari, and go straight to Preview to create a new file which can instantly be edited or converted.

You can resize, rotate, or flip any image file via the Mac’s Terminal using the command line sips tool. Manipulating images with sips is practically instantaneous, if you need to quickly resize, rotate, or flip an image file it definitely beats firing up Preview.

Resizing an image from Terminal

You can resize any image with sips using the following syntax:
sips -z 600 800 test.jpg The format is height first then width, so despite the command appearing dimensionally backwards to many computer users, the above command would resize an image to be 800 pixels wide by 600 high.

Rotating images from the Terminal

By default, sips rotates clockwise so you just need to specify the degrees you want an image rotated, like so:
sips -r 90 image.jpg The file will immediately be rotated 90 degrees clockwise.

Flip an image from the Terminal

Using sips, you can also flip any image vertically or horizontally from the command line, here’s an example:
sips -f horizontal image.jpg This will instantly flip image.jpg horizontally, you can just as easily flip the image vertically by replacing horizontal with vertical like so:
sips -f vertical image.jpg

You can easily transfer Photos from your iPhone to your computer, the process is very similar whether you are on a Mac or PC. Regardless of what OS you are using, you’ll need your iPhone, the included USB cable, and a computer to plug it into.

Transfer Photos from iPhone to Mac

The easiest way to transfer pictures from your iPhone to your Mac is through Preview

• Plug your iPhone into your Mac
• Launch Preview
• From the File menu navigate down and select “Import from iPhone…”
• Select “Import All” to get all the pictures, otherwise individually select pictures and click ‘Import’
• Look in your ~/Pictures/ folder for the photos from your iPhone

You can also transfer pictures to your Mac with iPhoto or Image Capture, which is just as easy.

Transfer Photos from iPhone to PC

On a Windows PC the easiest way to get pictures from your iPhone is to just use Windows Explorer, but there’s two ways to go about this:

• Plugin your iPhone to the computer without iTunes running
• Wait for a popup asking you what you want to do with the device
• Select “View Content”
• Find your photos through the folders that are displayed
• Copy in Windows as usual

If your iPhone is already plugged into your PC, you can try this method:

• Plugin your iPhone to your PC
• Open “My Computer”
• Find your iPhone, it will appear as any other camera would
• Open iPhone to find your Photos
• Select the pictures you want to copy to your computer and copy/paste them into the desired location on your PC

The Windows approach treats the iPhone more like a file system, but if you feel like it you can also use your favorite photo importing application to pull the pictures from the device as well.

You can also sync your photos using just iTunes on either Mac OS or Windows but that is more for iPhone backup purposes.

ShrinkIt is a handy little app that greatly reduces the file size of Illustrator generated PDF’s. Created as an internal tool, the developers over at Panic realized that PDF files saved from Adobe Illustrator were loaded with loads of extra nonsense metadata, even patterns, preview bitmaps, swatches, creating enormous PDF file sizes when they should be much smaller. The solution? Process the Adobe bloatfile through Apple’s PDF processor. You can do this yourself through Preview, but it’s a pain to open and re-save tons of PDF files, thus the creation of ShrinkIt. Now you can drag and drop your Illustrator PDF’s into ShrinkIt and you’ll save a whole lot of space (the original file is always kept, just renamed).

ShrinkIt is for Mac OS X 10.6 Snow Leopard only.

ShrinkIt developer home
Download now

You can view .PSD Adobe Photoshop files directly in Mac OS X with no additional software, thanks to Quick Look and Preview.

To get a fast preview of a PSD file, simply select the document within the Finder and hit the Spacebar to launch the PSD file rendered in Mac OS X’s very own Quick Look. If you want a bit more control over viewing the PSD file (zoom, resize, whatever), you can take it a step further by opening the PSD document within the Preview app, just drag and drop it onto the application icon and away you go (note some versions of Mac OS X will automatically open PSD files within Preview if you just double-click on them, assuming Photoshop is not installed on the Mac).

If you want to edit a PSD file with the same type of capabilities as Photoshop without paying for it, you could try using Gimp, a free open source Photoshop clone. It’s not perfect but works pretty well for image editing, and if you’re not trying to do anything overly complex, it’ll save you a few hundred bucks.

Recently Preview.app was refusing to open some image files for what seemed like no reason, I wasn’t even able to drag the image file onto the Preview icon to open it. I know the images are fine because they open fine in Windows and even in Photoshop, so how can I force Preview to open the images? Pretty easy really: hold down Command+Option keys while dragging a file onto the Preview icon, this will force any file to open through Preview (you could force a text file into preview if you wanted with this, but obviously preview will only render compatible files).

Using this method, the images worked fine, I was able to resave them, and now they’re back to opening in Preview as usual. I’m not sure what the cause of this problem is, perhaps the image EXIF or meta data was corrupted. I remembered this trick from a post a few years back by our very own David Mendez, how to force open a file in Mac OS X, and this actually will work with nearly every application and file, so if you want to force an image file into TextWrangler, you could do that too.

You can convert many different image file formats in Mac OS X for free using the included Preview application. As of Mac OS X 10.6, Preview supports the following file types and will convert between any of them: GIF, ICNS, JPEG, JPG, JPEG-2000, Microsoft BMP, Microsoft Icon, OpenEXR, PDF, Photoshop (PSD), PICT, PNG, SGI, TGA, TIFF

Here’s a very simple walkthrough to convert images within Preview:

* Open the image file you want converted within Preview
* From the File menu navigate down to ‘Save As’
* Select the file format you want the image converted to from the ‘Format’ drop down list
* Click “OK” to save and convert the image to the new format

The above process will hold true regardless of the origin images file format and the desired file format.

Preview.app supports a wide range of image conversions: GIF to JPG, JPG to GIF, PSD to JPG, JPG to PDF, JPG to BMP, BMP to JPG, BMP to GIF, PNG to GIF, JPG to PNG, TIFF to JPG, and just about every other variation between these and more. As long as the image format is supported by Preview, it will convert it to any other supported file format.

You can delete specific pages from a PDF file with the built-in Mac Preview app, just select/highlight the page you want to delete and then hit the delete key. This is really useful for paring down large PDF documents if you only need a few select pages, this is bound to make any student or researchers life easier when emailing or printing documents.

In the above screenshot example, I have deleted multiple unnecessary pages within a research PDF document before I printed it, my school charges for each page so reducing the printed page count is particularly valuable. You’ll notice that the PDF page numbers don’t change though, which is both good in that you can quickly identify which pages are missing, and bad if you are hoping the pages would reorder themselves after others were deleted.

Converting a PNG file to JPG is really easy in Mac OS X, here are the steps:

* Launch the origin PNG file within Preview
* Navigate to the File menu and down to ‘Save As’
* Select “JPG” under the ‘Format’ drop down list
* Click “OK”

Your PNG file now has been converted and saved as a JPG file to the location you specified! If you want you can go back and delete the origin PNG file. Naturally you could reverse the process and save a JPG file as a PNG file to do the opposite conversion.

You can easily batch resize groups of images within Mac OS X by using the included Preview app, there is no need for any additional downloads or expensive photo editing applications, only Preview, which is free with your Mac! Here’s how to do it:

Batch resize images in Mac OS X

1. Select all the images you want resized and open them within Preview
2. From Preview, select the images that you want to batch resize from the drawer (Command+A will select them all)
3. Now, go to the menu labeled Tools, and then Adjust Size
4. Enter a value for what you want the new width and height to be
5. Next, navigate to the File menu and click Save All
6. All the images you selected are now resized!

This works in Preview that is included in virtually all versions of Mac OS X, happy batch resizing!

Updated: 5/10/2012 This continues to work in OS X Lion and OS X Mountain Lion.