Operators Dialog / Operator Details

§ 12.11.21 - Crop

Scripting command: crop [ToEdgeAlpha=0...1] [AlphaLevel=0...255] [Reflect=0...3]

Note: All available scripting operations are listed on the Script operator page.

The crop operator

Cropping is simple: select an area, you get a new image containing that area.

Try out the various guide and aspect settings. They are there to help you make better crops. They can also be set to be on, or off, whenever you make a rectangle or ellipse (oval) area selection. See the Preferences dialog for the relevant settings.


Original image showing region to be cropped


Crop result without reflection

If you check  Make Fully Reflected Tile the resulting crop will be a double-width, double-height image containing content suitably mirrored three ways to perform as a tile fill (tile fills are typically performed with Merge operator.)


Fully reflected result

Fill using Merge operator

If you check  Make Horizontally Reflected Tile the resulting crop will be a double-width image containing content left-right mirrored.


Horizontally reflected result

If you check  Make Vertically Reflected Tile the resulting crop will be a double-height image containing content top-bottom mirrored.


Vertically reflected result

Tip: If you'd like to convert an existing image into a mirrored tile, use the entire image areatool on it with Crop operator and see that one of the tile controls is checked.

If you check  Crop to Edge Alpha then the operator will create a crop that removes image edges that are transparent, or partially transparent. The degree of transparency is set with Alpha Level . When used in this fashion, the crop operator creates its own area selection, hence the guides and aspect options are disabled. Typically you'd think of this as an automated version of the rectangle area tool.

The effect of the Alpha Level slider is that any edge of the image that is less transparent is cropped away, and anything equal to or above that level is carried along as the crop result, retaining that level of transparency. For a fully opaque crop, set Alpha Level to 255.

Note: As images carry 16-bit alpha channels, the setting of the alpha level chooses levels spaced 256 levels apart in order to cover the entire Alpha range. The conversion of the 0 to 255 level slider to the 0 to 65535 level alpha is:

(256*level)+level
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