Crop and Straighten
Even with all of Photoshop's nifty selection, transformation and crop tools, the task of scanning in bunches of photographs has, up until now, required an annoying amount of rotation, cropping, copying, and pasting. Each photo in the scan had to be individually selected, then cropped or copied and pasted to a new document. Despite your best efforts, the photos are rarely perfectly aligned; at least a few usually cant off to one side or the other a few degrees, requiring further rotation and cropping (Figure 2.25).
Figure 2.25. Breaking a scan of multiple photos into individual images used to require a lot of cropping and straightening by hand. (©2005 Mark Clarkson)
But Photoshop's Crop and Straighten Photos does most of that work for you, identifying the individual photographs within the scan, rotating them into perfect horizontal and vertical alignment, and then copying them into new documents. It leaves the original document untouched.
 | The Crop and Straighten Photos command doesn't do as well with very low resolution scans; scan in photos at 150dpi or more for the best results. You can always scale down the images later. |
To use the command, place a handful of photos on your scanner and arrange them so that none of the images overlap, there is a good amount of space between each image, and none of them are pressed up against the edges of the scanner glass. The more space you leave between each image, the better of a chance there is for Photoshop to successfully crop and straighten each image. Once you've scanned them into Photoshop, make sure the layer containing the scan is active and then choose File > Automate > Crop and Straighten Photos. Without further notice, Photoshop will start chugging away at your document, creating one file for each image. It will also attempt to straighten each image (Figure 2.26). Crop and Straighten Photos does a pretty good job, but it can get confused. I find that it's always good to double-check its work because a few images might need to be fine-tuned by hand.
Figure 2.26. Crop and Straighten Photos will automatically locate, crop, and straighten multiple photos from a single scan. (©2005 Mark Clarkson)
If Crop and Straighten Photos insists on breaking one of your photos in two or, conversely, treating two photos as one, you may have to give it a little help. Use the Marquee tool to draw a selection around the problem photo. Now, hold down the Option key (Mac) or the Alt key (Windows) when you choose the command. Holding down this key tells Photoshop that there is only one photo within the selection, making it easier for the program to locate the borders. Even if you have to select some photos one at a time, the Crop and Straighten Photos command still saves you the work of rotating and cropping the photo, and then copying it to a new document.