OOF2: The Manual

Details

Description

Some pixel selection tools such as OOF.Graphics_n.Toolbox.Pixel_Select.Burn or OOF.Graphics_n.Toolbox.Pixel_Select.Color tend to leave small holes in the selection due to imperfections of the micrograph or other reasons. With only a few holes, it's possible to fill them manually with other tools in the Pixel Selection toolbox, but this quickly gets tedious. The Despeckle command fills these holes efficiently.

	Note
	Note that it's the pixel selection that is being despeckled, not the Image. The term “despeckle” is also used to mean removing noise from an image, and OOF2 does include Image despeckling with OOF.Image.Modify.Despeckle. OOF.PixelSelection.Despeckle selects pixels, but does not affect Images.

The end result of a despeckling is a solidification of the selecting region. Compare to Elkcepsed, which achieves a similar effect by deselecting pixels.

The microstructure parameter specifies the Microstructure where the selection resides.

The parameter neighbors controls the despeckling operation. Smaller values mean stronger filling power. The algorithm examines each unselected pixel, counts its selected neighbors (examining the 8 immediately adjacent pixels), and selects the target pixels if at least neighbors neighboring pixels were selected. The process repeats recursively until no more pixels are selected. The value of neighbors must be between 4 and 8 inclusive: values higher than 8 are meaningless, and values lower than 4 will cause all pixels to be selected. 4 itself is of dubious utility.

Figure 6.52. Despeckling the Pixel Selection

The upper left image shows a set of selected pixels, in red. The other images show the result of running Despeckle with various values of neighbors. With neighbors=8, only single pixel holes have been filled. With neighbors=7, one and two pixels holes have been filled. With neighbors=6, larger holes have been filled. With neighbors=5, holes have been filled and the the boundary has been smoothed. With neighbors=4, the despeckeled selection is very dissimilar to the original.

See Also