Gradient

Menu:   Processing > Filters… > Edges->Gradient

Script:   gradient

Use this function to extract the gradient information from an image. The function is based on Prewitt operator with an adjustable window. The application of each kernel to the original image creates two auxiliary differential images Xdif and Ydif which are combined in a certain way depending on the Mode selected. If an overflow occurs, the result is clipped to the minimum or maximum pixel value for the given image type.

If you choose this command, the following options will become available:

Input

Displays the input image frame number. If you want to process another image, type or select the corresponding value.

Output

Displays the number of the frame in which the output image will be created. Depending on the Preferences. ImageWarp will set it either to the first available value or to the Input frame number. Type or select another value if you want the output image to be created in a different frame.

Preview

Select this check box to watch the Preview of the output image.

Size

Lets you choose the mode in which the two differentials are combined:

Select Horizontal to have the target pixel substituted with the corresponding pixel from the horizontal differential image:

Select Vertical to have the target pixel substituted with the corresponding pixel from the vertical differential image:

Select Mean to have the target pixel substituted with the mean of the absolute values of the pixels in two differential images:

Invert

Select this check box to invert the outcome of the function. The dark and bright pixels indicating the edges will be swapped.