Stairstep Image Size is a Photoshop plug-in which uses a "stairstep" bicubic interpolation to resize (enlarge and reduce) images. Stairstepping is a method by which you take small steps until you arrive at your goal. In the case of resizing images, this method enlarges (or reduces) an image by small amounts multiple times until the desired size has been reached. Bottom line is that Stairstep Image Size is another image enlarging (scaling) program.

The user interface is very similar to Photoshop's Image Size except for the outlined items: Stairstep Interpolation and Fit Image. I will assume that you are familiar with Photoshop's Image Size and forgo explanation of Pixel Dimensions, Document Size, and Constrain Proportions. These work exactly as they do in Photoshop's Image Size.

Stairstep Interpolation: When resizing images, you can specify the percentage change per step (iteration) or the total number of steps. For example, if you specify 10 %/step, the program will increase (or decrease) the image size 10% per iteration until the desired size has been reached. Or you can specify 10 steps in which case it will do 10 incremental iterations. Stairstep Image Size uses Photosho's bicubic interpolation to resize the image. So, if you specify 100%/step or 1 step, it will resize the image only once and the result will be exactly the same as using Photoshop's Image Size. A value of 8-12%/step produces good results. A very low value (%/step) will produce very sharp and artifact-laden image whereas a high value will produce images with no discernible difference from using 100%/step.

Fit Image: The image will be fit into the size that you specify with proportions constrained. This option is useful when resizing both landscape and portrait mode images. For example, if half of your images are in portrait mode and the other half in landscape mode, you can resize all of your images to 4x6 by specifying 6x6 image size with Fit Image option checked. Landscape images will be resized to 6x4 while portrait images will be resized to 4x6.

Action scriptable: Stairstep Image Size is fully scriptable so that it can be recorded as an action step. This allows you to create actions with Stairstep Image Size and use Photoshop's Batch command to automate image resizing. The sample action below resizes images to 6x4 or 4x6 at 300dpi using Fit Image option:

Download Stairstep Image Size (37KB, Windows)

Installation Instructions