In my everyday work, resizing images is a fairly common task—for example, I frequently need to convert high-resolution product images down to 200-pixel versions for use in
Product Guide. Although there are
a good number
of graphics applications out there that can perform such a task—including the excellent
)—many of those apps are overkill if all you really want to do is resize a folder of images. (Not to mention that some are quite expensive for such a basic task.) So I’ve been looking for a quick-and-easy-and-cheap solution.
My search was further limited by a particular feature need: the ability to specify the maximum size of an image in
dimension, height or width. You see, many graphics apps let you resize images to a maximum height
width. But if your source images are a mix of horizontally- and vertically-oriented pictures, such an approach results in one of those groups being improperly resized. (For example, if you choose to proportionally resize images to 200 pixels wide, your vertical images will end up being taller than 200 pixels.) I needed an app that lets me say, “Resize these images so that the longest side is 200 pixels.”
For a while I was actually using an Automator workflow I’d created for just this purpose. But I recently found several better solutions, all “donationware” (payment requested, but not required for use). Note that these app are all limited to working with JPEG images.
The first is KStudio’s
). Although it hasn’t been updated since January of 2005, it worked flawlessly in my testing. Drag a folder of images onto Resize’s icon in the Dock or Finder (or into its window if the application is already running), and a dialog pops up with options for resizing the images in that folder. You choose the size and proportionality of the resize action—in my case, I set the Size value to “200” with the option for “Biggest,” meaning the longest side, chosen. (One other unique feature here is that you can choose the desired height
width—many apps let you choose only one or the other.) You can also choose the quality of the resulting JPEG images; to
the size of smaller images to fit your preferred image size; and to reformat image names to remove spaces and special characters (or even to use “8.3” DOS file names). Resize creates a new folder, at the same level as the source folder, containing the altered images, which are in JPEG format regardless of the input format.
One glitch I found with Resize is that whenever I accessed its Help system, I was presented with the following message: “This application uses unregistered plugins from Monkeybread Software. Please visit out website at www.monkeybreadsoftware.de/realbasic and register the plugins. Thank you.” Which leads me to believe that KStudio used Monkeybread’s RealBasic plugin for Resize’s Help dialog, not for the application itself. Odd.
A similar solution, more powerful but not quite as simple to use, is Fabien Conus’s
). Like Resize, you drag a folder—or multiple folders—of images onto SmallImage’s icon or into its window; you’ll then see a listing of the folder(s) and enclosed images. (One advantage of the list approach is that you can selectively remove images from the list to avoid altering them.) You choose the type of scaling (resizing): Relative (percentage) or Fixed, with the latter providing options for width, height, smallest side, largest side, maximum width, or maximum height. You can also add a suffix to the names of resized files, remove or add thumbnail icons, and re-compress the resulting images. A unique option is the ability to strip any or all ICC, EXIF, IPTC, Finder, or other profile information from images—for privacy or to reduce the size of images. (This “information scrubbing” can be performed without actually altering the image.) SmallImage saves the modified images in the same directory as the originals; you can even replace the originals if desired.
SmallImage 2 also has a few other features that go beyond resizing. By clicking the Info button in the toolbar, you can view detailed information about each file: quality, file info, dimensions, metadata, camera info, and EXIF info. You can also view a small preview of an image (although you have to manually click the preview button for each image). Finally, you can save presets of image settings for future use.
Finally, fans of contextual menus will enjoy Pixture Studio’s
). You don’t need to launch a separate application to access PhotoToolCM’s features; simply right/Control-click on an image or a group of images in the Finder to bring up the Finder’s contextual menu. The Photo Tool submenu provides a number of useful options, one of which is Batch Resize.
Choosing this option brings up the Batch Resize dialog, where you can choose how to resize images (Long Side satisfies the task described above); the resulting image quality; the output location and file name; and whether or not to create thumbnail icons. An especially useful feature is the sharpness filter, which can improve clarity and readability on downsized JPEG images. Depending on PhotoToolCM’s preferences, you can save the modified images in the same directory as the originals or a different location.
In addition, a number of other options are available directly from the Photo Tool submenu: You can rotate, flip, or transform (rotate and flip) selected images without any loss in quality; edit Finder comments or EXIF date information; “clean” images (remove thumbnails and photo information to reduce size) losslessly; and rename files using EXIF date information. You can also add one of 56 “frames” (actually masks) to each image. PhotoToolCM’s preferences dialog provides a number of additional features and customizations.
PhotoToolCM is the most feature-rich of the three products I’ve covered here. Unfortunately, it’s currently incompatible with Intel Macs.
(I also tried another utility that looked promising,
photo Drop, which lets you create individual drag-and-drop “droplet” applications that each perform specific image manipulations. Unfortunately, whenever I tried to use one of these droplet applications, a dialog popped up with two options: More Information or Quit. Clicking the first took me to the developer’s Web site and quit the droplet; clicking the Quit button did what it claimed. In other words, I couldn’t use these droplets at all. Which is too bad, as photo Drop looked like a neat app.)
So what’s the
of resized images produced by these utilities? Suprisingly, it varies quite a bit. Below are samples of the same screenshot—SmallImage 2’s main window—resized by each app from its original size of 738 pixels wide down to a smaller image, 470 pixels in width:
Resized using SmallImage at maximum (100%) quality.
Resized using Resize at Excellent (90%) quality.
Resized using PhotoToolCM at High (80%) quality with no filter.
Resized using PhotoToolCM at High (80%) quality with medium sharpness filter.
The resulting files were between 56k and 68k in size. As you can see, when I resized the image in SmallImage 2, the resulting image was very grainy, even when I chose the highest quality output. Resize and PhotoToolCM produced much better results, with PhotoToolCM’s sharpness filter offering slightly better text readability (although with a bit of graininess itself).
The biggest drawback of SmallImage and PhotoToolCM, at least in my work, is that they can’t convert
JPEG from other image formats (or convert between any formats, for that matter); Resize will convert from any QuickTime-supported image format to JPEG. But if you need to quickly resize batches of JPEGs, any of these utilities will fit the bill…and then some. Resize is the easiest to use, but SmallImage and PhotoToolCM offer more options. PhotoToolCM provides the best image output, SmallImage the poorest. My personal favorite is PhotoToolCM; too bad I can’t use it on my Intel Macs.
Resize! is available for Mac OS 8—yes, 8—and later. SmallImage 2 works with Mac OS X 10.3.9 and later and is a Universal binary. PhotoToolCM works with Mac OS X 10.2 (Jaguar) and later; it does not currently work on Intel Macs.
Update 7/12/2007: Corrected information about Resize’s conversion functionality.
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Dan is former Macworld senior editor. You can find him on the web at danfrakes.com.