Digital Focus: Fix Perspective in Your Photos

Shooting tall buildings can be tricky. Here's a slick fix.

Dave Johnson

Feature: Correct Your Perspective

Have you ever noticed how photographs of buildings tend to come out with walls that curve or stand at odd angles? It's ugly, to be sure, but it's a common effect nonetheless. When you look at things like tall buildings, your brain does a lot of "corrections" behind the scenes to make them look right in real life. But your camera doesn't have the same sort of mechanisms, and so your pictures can suffer from perspective problems.

In fact, your pictures will exhibit something known as "perspective distortion" whenever you hold the camera at an odd angle, not parallel to the ground. In the film world, there are special camera lenses made for this kind of photograph. Professional photographers have to spend a lot of time setting up architecture shots to eliminate perspective distortion--thus ensuring that parallel lines will stay parallel in the photograph--before they even press the shutter release. Thankfully, in the digital world, it's easy to correct for this in an image editor like Paint Shop Pro 8 or Adobe Photoshop Elements.

Suppose you've taken a photo of the Times Square area of Manhattan from a hotel-room window. Since the camera was pointed down, the buildings are distorted: The buildings bend inward at the top of the photo and the building on the right has jagged vertical lines running up the front of it.

Using Paint Shop Pro

To fix this image in Paint Shop Pro 8, you can use the new Perspective Correction tool. (If you're using an older version of Paint Shop Pro, or another image editor, be patient: I'll tell you about another way to do this later.) Select it from the tool palette--it's the second tool from the top, but you might have to choose it from the drop-down menu, since PSP now packs multiple tools into each space.

You should see a box appear in the image. Use the mouse to align the top of the box over the building on the right (the one with the most apparent distortion), and position the box so it outlines the front of the building.

When you're done selecting the building, click the OK check box at the top of the screen. PSP corrects the distortions throughout the image. To finish up, you simply need to crop the image to a more traditional rectangular shape (by cropping out the white portions) and save it.

Or Do It by Hand

What if you're using an image editor that doesn't have a nifty Perspective Correction tool? You can still correct the image, but you'll have to do it yourself. If you use Adobe Photoshop Elements, for instance, you'd open the image and then create a new layer. To do that, double-click the layer's name in the Layers Palette (which usually opens in the lower right corner of the screen). Now choose Image, Transform, Distort from the menu, and you'll see a box appear at the edges of the image window.

At this point, it's easiest to enlarge the image window so you can better see the Distort box. Maximize the image. Now grab the top left and right corners of the box and drag them away from the image, stretching the top of the picture. You'll have to play with it a bit, but you should be able to correct almost all of the distortion in the buildings. When everything looks about right, accept the changes and crop the image back to a rectangle. You're done!

Finally, if you still use Paint Shop Pro 7, you can make a similar correction. Select Effects, Geometric Effects, Perspective--Vertical. Move the slider until the photo looks the way you want it to in the preview box, then click OK to implement the change.

Dave's Favorites: Paint Shop Pro 8

I've been recommending Paint Shop Pro 7 for several years now. But several years is an eternity in the software world--and in the interim, I started using Adobe's Photoshop Elements to supplement PSP7 because this newer image editor offered some tools that the aging Paint Shop Pro didn't.

At long last, Jasc has released Paint Shop Pro 8. Now that I've had a chance to get to know PSP8, I heartily recommend it... but while it's a terrific program that has goodies Photoshop Elements doesn't, it still lags behind in a few small ways.

Overall, Paint Shop Pro 8 is a winner. It's one of the most comprehensive image editing programs I've ever seen, and it's aimed at average folks--people that want to improve their photos, but don't want to take a lot of time mastering a complex program in the process. To that end, Jasc has built in a useful "learning center" that offers step-by-step instructions for completing a wide range of tasks.

Moreover, the program includes some amazing new tools. At long last, PSP has a white point control, which lets you color-correct a photo that has an obvious color cast with a single click. Other tools simplify the process of fixing your photos, like a feature that automatically straightens crooked pictures. My favorite new gadget is the background eraser, which you can use to remove the background from an image, isolating your subject. It's smart enough to leave individual strands of hair in place on your subject's head--a task that would otherwise require you to muck around with masks and other advanced tools. Stuff like that opens up all sorts of new possibilities for using your digital images.

If that's not enough, Paint Shop Pro also comes with a batch processing mode that you can use to automate common image editing tasks on a slew of pictures at once. It's like Jasc's old Image Robot program, only now it's built in.

Despite all those cool tools, I'm annoyed that Jasc failed to make some features a bit friendlier. In Photoshop Elements, for instance, you can rotate an image by grabbing a corner and moving the mouse. In PSP, the "free rotate" mode requires you to guess how many degrees you'd like to turn the image and then try again when that turns out to be amiss. But that's a minor complaint. Paint Shop Pro is a worthy upgrade. It has a huge array of automated tools for beginners, but also offers all the hands-on adjustability that more advanced users could possibly want.

At press time, I found Paint Shop Pro 8 for as low as $83 at the PCWorld.com Product Finder.

Q&A: How Do I Keep My JPEGs from Shrinking?

If I take a picture and put a copyright notice in the corner, when I save it, the file becomes less than half the size. The resolution is still the same, but the actual file size is dramatically lower. How can I save a digital image without losing file size?

--Marj I, Spokane

I assume, Marj, that you are working with JPEG files. And it sounds to me like you are inadvertently changing the JPEG compression when you resave your pictures, probably because your image editing program defaults to a higher compression factor than your digital camera is using to begin with.

There are two factors that determine the overall quality of your digital images: resolution and compression. Resolution is the number of pixels in the picture; compression measures how much image quality is sacrificed in order to keep the file size small. A lower compression factor more accurately preserves your images, but results in bigger overall file sizes.

The solution is to adjust the compression before you resave your files. Check your image editing program's options or preferences menu for a way to set the JPEG compression rate to the lowest compression possible.

Hot Pic of the Week

Get published, get famous! Each week, we select our favorite reader-submitted photo based on creativity, originality and technique. Every month, the best of the weekly winners gets a prize valued at between $15 and $50.

Here's how to enter: Send us your photograph in JPEG format, at a resolution no higher than 640 by 480 pixels. Entries at higher resolutions will be immediately disqualified. If necessary, use an image editing program to reduce the file size of your image before e-mailing it to us. Include the title of your photo along with a short description and how you photographed it. Don't forget to send your name, e-mail address, and postal address. Before entering, please read the full description of the contest rules and regulations.

This week's Hot Pic: "Pot Roasted Bunnies," by Robert F. Hebron, Redmond, Oregon

It's not as bad as it looks, folks. Robert says that his kids found a trio of bunnies in a pile of hay that was being unloaded from a truck, and so the family adopted the fuzzy little guys, bottle-feeding them long enough until they could survive on their own. After that, they let them go. "But before we did," Robert says, "I had a little fun with my camera!"

We want your feedback! Send your comments, questions, and suggestions about the newsletter itself to comments@bydavejohnson.com. If you have a question that you'd like to see answered in the weekly Q&A, send it to question@bydavejohnson.com.

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