A composite operation combines pixels from a different image with your target image. You can control composition by choosing which image to combine, where the combining occurs (the offset from the target image), and how the pixels are combined (composite operation).

Select your composite image, press Browse to browse and select your image file or enter the URL of your image. Use clipboard: as the filename to import a previously saved image from the ImageMagick Studio clipboard.

The offset geometry specifies the (x,y) offset from your target image to combine the composite image. The x and y offset are conveniently specified as one value. For example, to offset the target image by 30 pixels in the horizontal direction and 40 pixels in the vertical use:

  +30+40

For convenience, you can select a gravity instead of an offset geometry. For example, Center centers the image. The location geometry has precedence over any gravity.

Finally, you need to specify how the pixels are combined. By default, each of the composite image pixels are replaced by the corresponding image tile pixel. You can choose an alternate composite operation. How each operator behaves is described below.

Clear
Both the color and the alpha of the destination are cleared. Neither the source nor the destination are used as input.

Src
The source is copied to the destination. The destination is not used as input.

dst
The destination is left untouched.

Over
The source is composited over the destination.


DstOver
The destination is composited over the source and the result replaces the destination.

In
The part of the source lying inside of the destination replaces the destination.


DstIn
The part of the destination lying inside of the source replaces the destination.
Out
The part of the source lying outside of the destination replaces the destination.

DstOut
The part of the destination lying outside of the source replaces the destination.

Atop
The part of the source lying inside of the destination is composited onto the destination.

DstAtop
The part of the destination lying inside of the source is composited over the source and replaces the destination.

Xor
The part of the source that lies outside of the destination is combined with the part of the destination that lies outside of the source.

The following compositing operators add blending of source and destination colors beyond the base 12 Porter-Duff operations. The behavior of these operators necessitates clamping of the output values after compositing.

Plus
The source is added to the destination and replaces the destination. This operator is useful for animating a dissolve between two images.

Multiply
The source is multiplied by the destination and replaces the destination. The resultant color is always at least as dark as either of the two constituent colors. Multiplying any color with black produces black. Multiplying any color with white leaves the original color unchanged.


Screen
The source and destination are complemented and then multiplied and then replace the destination. The resultant color is always at least as light as either of the two constituent colors. Screening any color with white produces white. Screening any color with black leaves the original color unchanged.


Overlay
Multiplies or screens the colors, dependent on the destination color. Source colors overlay the destination whilst preserving its highlights and shadows. The destination color is not replaced, but is mixed with the source color to reflect the lightness or darkness of the destination.

Darken
Selects the darker of the destination and source colors. The destination is replaced with the source when the source is darker, otherwise it is left unchanged.

Lighten
Selects the lighter of the destination and source colors. The destination is replaced with the source when the source is lighter, otherwise it is left unchanged.

ColorDodge
Brightens the destination color to reflect the source color. Painting with black produces no change.

ColorBurn
Darkens the destination color to reflect the source color. Painting with white produces no change.

HardLight
Multiplies or screens the colors, dependent on the source color value. If the source color is lighter than 0.5, the destination is lightened as if it were screened. If the source color is darker than 0.5, the destination is darkened, as if it were multiplied. The degree of lightening or darkening is proportional to the difference between the source color and 0.5. If it is equal to 0.5 the destination is unchanged. Painting with pure black or white produces black or white.

SoftLight
Darkens or lightens the colors, dependent on the source color value. If the source color is lighter than 0.5, the destination is lightened. If the source color is darker than 0.5, the destination is darkened, as if it were burned in. The degree of darkening or lightening is proportional to the difference between the source color and 0.5. If it is equal to 0.5, the destination is unchanged. Painting with pure black or white produces a distinctly darker or lighter area, but does not result in pure black or white.

Difference
Subtracts the darker of the two constituent colors from the lighter. Painting with white inverts the destination color. Painting with black produces no change.

Exclusion
Produces an effect similar to that of 'difference', but appears as lower contrast. Painting with white inverts the destination color. Painting with black produces no change.

The image compositor requires a matte, or alpha channel in the image for some operations. This extra channel usually defines a mask which represents a sort of a cookie-cutter for the image. This is the case when matte is 255 (full coverage) for pixels inside the shape, zero outside, and between zero and 255 on the boundary. For certain operations, if image does not have an matte channel, it is initialized with 0 for any pixel matching in color to pixel location (0,0), otherwise 255. properly borderwidth must be 0).


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