Zooming Without Pixelation

One of the more common effects that you will see with Photo Story is a zoom-in-to or zoom-out-from a specific area (this technique, which also consists of panning, was pioneered by Ken Burns).  Some of these effects are just part of the default behavior that Photo Story assigns to slides.  Of course, you have full control over the actual motion that you want Photo Story to give your slide.  If you need a refresher on how change the default motion of slides, please see the Customizing Motion section of the Beginner's Guide to Photo Story.

You may have noticed with most images, Photo Story can zoom into an area or zoom out from an area with little or no pixilation occurring.  On the other hand, you may wonder why some images look less-than-perfect while zooming in.  This article will explain why, and will give you ideas on how to both minimize pixilation and maximize the dramatic, and beautiful effect of zooming.

What is Pixelation?

In this case, pixelation describes the blocky effect that occurs when an image is magnified to the point that the curves and overall picture of an image begins to give way to the pixels that make up the image. From whatis?com: Pixelation is the display of a digitized image where the individual pixels are apparent to a viewer. This can happen unintentionally when a low-resolution image designed for an ordinary computer display is projected on a large screen and each pixel becomes separately viewable.

Notice in the image above, the very blocky image that is revealed when zooming in.  This is because all of the original pixels were simply made larger.  The more an image is scaled, the poorer quality the image will have.  In order to make this less of a problem, Photo Story will do calculations and smoothing to reduce the blockiness.  However, some simple preventative techniques that you can do beforehand will make a significant difference when you are ready to tell your story.

How to Completely Eliminate Pixelation in Photo Story

Since pixelation occurs when zooming in, we can eliminate it by eliminating the need for increase the size of pixels.  Sound impossible?  It isn't.  All you have to do is have "more pixels than you need" in an image.  If we think of pixels as "detail" then it may be easier to understand that we want "more detail than we need" -- so that if we ever zoom in and need more detail, we have it.

Assuming a computer monitor is our target media, we need to have more detail than needed for this device.  While you may not generate full-screen stories, we'll at least prepare for this possibility.

At the typical monitor resolution of 1024x768, you can see that gives us 1024 pixels in width, 768 pixels in height, and a total of 786,432 pixels.  We need at least this many pixels in our source images to have a non-pixelated 1:1 zoom.  If you want to zoom in closer, say 2:1, you will need higher resolution source images to provide the missing "detail."

Since a standard 5Mpx camera has over 5,000,000 pixels per photo, you will have over six times the pixels you require at a normal zoom.... giving you plenty of detail to discover!  That means that at 1024x768, you are actually "zoomed-out" and detail is being obscured, which is acceptable because it is not obvious to the viewer.  And you are free to zoom in without pixels being a distraction from the story.

The Bottom Line

You can completely eliminate pixelation simply by using source photos that are much larger in resolution (more detailed) than your final output.  Avoid using small photos when possible, especially if they are smaller than the final output.  Never zoom into an image that is smaller than the final output if you want to prevent pixelation from occurring.

Photo Story will do all it can to keep your photos looking their best, even if you fail to provide high-quality sources.  However, there is so much that you can do to make an incredible presentation if you understand what is going on behind the scenes.