iOS Components and Frameworks: Understanding the Advanced Features of the iOS SDK

Core Image Filters

The sample app allows the user to select a starting image, and select a sequence of filters to apply to that image to arrive at a final image. As a general rule, Core Image filters require an input image (except in cases in which the filter generates an image) and some parameters to customize the behavior of the filter. When requested, Core Image will process the filter against the input image to provide an output image. Core Image is very efficient in the application of filters. A list of filters will be applied only when the final output image is requested, not when each filter is specified. In addition, Core Image will combine the filters mathematically wherever possible so that a minimum of calculations are performed to ...