|Microsoft DirectX 9.0|
The Contrast Filter is a video transform filter that implements a contrast effect. This sample illustrates how to define and implement a simple custom interface. It also demonstrates how to use the CTransformFilter class to implement a simple effect filter.
Source: (SDK root)\Samples\C++\DirectShow\Filters\Contrast
The Contrast filter is a simple transform filter that adjusts the contrast of an 8-bit palletized video stream that is passed through it. It provides a custom interface for adjusting the contrast. The Contrast filter also uses the CBasePropertyPage class to provide a property page for applications that do not provide a user interface.
The Contrast filter adjusts the contrast by manipulating the image palette. By changing the palette, the filter changes the contrast without changing the image pixels themselves.