7.2. Stage 2
7.2.1. Preparing the pictures
In order for the Panotools filters to work properly, the raw source images must be cropped, and the dimensions of the different pictures must be exactly the same.
The pixel is the unit of measurement here, because pixels will later be used to enter the photographs' dimensions into a BBEdit script.
I opened all the pictures in Photoshop and measured the circular image's diameter using the Measure tool and reading the figures in the Info palette. I rounded off the diameter to 1780 pixels.
Measuring the useable diameter
In the Image→Canvas Size dialog box, I cropped the pictures using the 1780 pixel value I obtained earlier. If the camera's CCD sensor is correctly centered, the cropped picture should just brush the edge of the circle. I cropped the other pictures in the same manner.
When Photoshop's warning message appeared ("The new canvas size is smaller than the current canvas size; some clipping will occur"), I clicked the Proceed button.
If a centering error occurs, cancel the operation and crop the images by hand using Photoshop's Rectangular Marquee tool. Enter the values as measured in the tool's options by opening the Style dropdown menu (below Photoshop's menu bar) and selecting Fixed Size.
Warning: You must save these images in TIF and JPEG format, both in RGB. (The Panotools plugin supports 8- and 16-bit images, but not CMYK separations.) You'll use the TIF files for the later montage assembly.