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# init(extent:format:)

Initializes an image accumulator with the specified extent and pixel format.

```
init?(extent: CGRect, format: CIFormat)
```

## Parameters

`extent`

A rectangle that specifies the x-value of the rectangle origin, the y-value of the rectangle origin, and the width and height.

`format`

The format and size of each pixel. You must supply a pixel format constant, such askCIFormatARGB8  (32 bit-per-pixel, fixed-point pixel format) or kCIFormatRGBAf (128 bit-per-pixel, floating-point pixel format). See [`CIImage`](/documentation/CoreImage/CIImage) for more information about pixel format constants.

## Return Value

The initialized image accumulator object.

## See Also

[`imageAccumulatorWithExtent:format:`](/documentation/CoreImage/CIImageAccumulator/imageAccumulatorWithExtent:format:)

Creates an image accumulator with the specified extent and pixel format.


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