Contrast and Brightness Adjustment

These two filters are implemented with a single linear transform taking parameters “alpha” (\(\alpha\)) and “beta” (\(\beta\)). Pixel values are multiplied by \(\alpha\) to adjust contrast, then have \(\beta\) added to adjust brightness: \[ g(x) = \alpha f(x) + \beta \] In effect the magnitude of \(\alpha\) corresponds to the amount of contrast and the magnitude of \(\beta\) corresponds to the amount of brightness.