Here are instructions to size, sharpen, and save digital images for projection during PSRI competitions.
This technique permits the photographer to shape the image to the best advantage without regard to height and width constraints. Once the image has been edited for color, contrast, brightness, etc., the image can be sized to fit within the constraints of 1400 x 1050, regardless of the proportions of the image. In reading the document below on preparing digital images, substitute the current dimensions, 1400 x 1050, in the instructions.
Preparing Digital Images for Projection
Color Space and Bit Depth Settings