A range of predefined filters are available, in addition to the option of explicitly specifying the 3x3 convolution matrix.
This option allows access to a range of Fourier domain filters. Note that in the absence of a frame processor board, the time required to compute the FFT and inverse FFT tranformations leads to slow execution of these filters.
I This option allows access to a range of filters taylored specifically to 'improving' an image in which the two halves of the interlace contain different information.
L Perform a fast low pass convolution filter on the buffer, using a kernal of user selectable size. Note that this filter may be applied only to the entire screen and suffers from round off error (frequently this error will be of little concern). Moreover, the image is erroded from the edge as the filter assumes the initial image is a doubly periodic function in space. For more general convolution filters, use the C option for the convolution filters submenu.
M This option allows access to a range of morphological filters such as erosion and dilation filters.