8.3. Edge
8.3.1. Activating the filter
You can find this filter through Filters → Edge-Detect → Edge….
8.3.2. Options
图 17.166. Edge filter options
Presets, “Input Type”, Clipping, Blending Options, Preview, Split view
注意 | |
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These options are described in 第 2 节 “Common Features”. |
Algorithm
Edge detector offers several detection methods:
Sobel
Here, this method has no options and so is less interesting than the specific Sobel.
After applying the filter (Sobel option)
Prewitt compass
Result doesn’t look different from Sobel.
After applying the filter (Prewitt compass option)
Gradient
Edges are thinner, less contrasted and more blurred than Sobel.
After applying the filter (Gradient option)
Roberts
No evident difference from Sobel.
After applying the filter (Roberts option)
Differential
Edges less bright.
After applying the filter (Differential option)
Laplace
Less interesting than the specific one.
After applying the filter (Laplace option)
Amount
A low value results in black, high-contrasted image with thin edges. A high value results in thick edges with low contrast and many colors in dark areas.
Border behavior
Where the edge detector will get adjoining pixels for its calculations when it is working on the image boundaries. This option will only have an effect on the boundaries of the result (if any). Clamp is the default and the best choice.