Hack 82 Get the Big Picture with a Little Camera Phone

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If a scene is just too big to fit in your little camera phone, shoot a series of images and stitch them together .

Have you ever photographed a breathtaking landscape or something extremely tall, such as a giant redwood or skyscraper, only to feel a little disappointed when looking at the image on the computer screen? The scale of the scene didn't survive the translation to the computer.

One reason is that the conventional camera has a monocular field of view, which is much smaller than the stereoscopic field of view that our two eyes provide. This issue is compounded by the camera phone's generally low resolution (sub-megapixel) and narrow depth of field; objects are not sharp, except for a narrow range of distance from the camera. You also might not be able to back up far enough to get a large vista or object entirely in a single frame.

One way to solve this problem is to photograph the scene or object in segments and then assemble the pieces into a single large image. The technique, called a panorama [Hack #19] , is pretty simple. Figure 7-14 shows three pictures stitched together into one.

Figure 7-14. A panorama created from three camera-phone images
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Here are a few tips to keep in mind when you're creating these types of images:

  • Decide which kind of panoramic image you want to create. The two most likely choices are horizontal and vertical.

  • Some digital cameras provide on-screen tools to help you line up stitched images as you're shooting them. Camera phones, however, do not have this feature. You can work around this by visually scanning the area you want to photograph and choosing visual segmentation points to help you line up the photographs and create assembly segments. The rule of thumb is to overlap each frame by 30%.

  • Camera phones don't have sockets that you can attach to tripods to ensure smooth panning. So, this is hand-holding country. To produce the best results, minimize your body movement when you're photographing each segment. I recommend keeping your feet in a single spot throughout the entire process. Twist your waist, while keeping your back as vertical as possible, for horizontal panorama scenes. When photographing vertical scenes, try to bend your shoulders and waist straight back (when shooting upwards) or forward (when shooting down). These behaviors minimize segment mismatches that create unusable visual areas.

  • Bring the photo segments into a photo-stitching (sometimes referred to as photo-merging) application. A number of general-purpose, commercial photo-editing applications include photo-stitching tools, such as Photomerge in Photoshop CS and Elements.

  • Standalone photo-stitching tools, such as ArcSoft PanoramaMaker (http://www.arcsoft.com/en/products/panoramamaker/), are also available. For this project, I used the PhotoStitch application that came bundled with my Canon PowerShot G3 digital camera. You can also find open source photo-stitching tools associated with the Panorama Tools project (http://panotools. sourceforge .net/).

  • Most applications automate the bulk of the actual photo-stitching process. However, there are usually options to adjust for different ways of producing and merging segmented images. You should experiment with these different methods to learn which ones work best with your photographic technique.

I'll now walk you through the basic steps of creating a panorama with your camera phone. First, take your series of shots, working left to right and overlapping by 30%. Upload the pictures to your computer. Open the images in your stitching program, as shown in Figure 7-15.

Figure 7-15. A series of shots in Canon's PhotoStitch application
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Now, merge the images together, as shown in Figure 7-16. If you give the stitching application enough visual information to work with, it will do an amazing job of creating a seamless panorama.

Figure 7-16. Photos being merged together
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Once the application works its magic, you have a much broader view. Crop out the rough edges, as shown in Figure 7-17.

Figure 7-17. Cleaning up after the merge
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A bonus of using this technique is that you've also added resolution to your landscape, which enables you to make a bigger print than you'd be able to make of a single 640 480 picture. You don't have to be limited to small prints or narrowly composed scenes with your camera phone. Just remember to gather all the parts while you're taking the pictures. Then, pull things together later on the computer. It's that easy.

Todd Ogasawara

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Digital Photography Hacks
Digital Photography Hacks: 100 Industrial-Strength Tips & Tools
ISBN: 0596006667
EAN: 2147483647
Year: 2004
Pages: 161
Authors: Derrick Story

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