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# init(cgImage:)

Returns a bitmap image representation from a Core Graphics image object.

```
init(cgImage: CGImage)
```

## Parameters

`cgImage`

A Core Graphics image object (an opaque type) from which to create the receiver. This opaque type is retained.

## Return Value

An [`NSBitmapImageRep`](/documentation/AppKit/NSBitmapImageRep) object initialized from the contents of the Core Graphics image.

## Discussion

If you use this method, you should treat the resulting bitmap [`NSBitmapImageRep`](/documentation/AppKit/NSBitmapImageRep) object as read only. Because it only retains the value in the `cgImage` parameter, rather than unpacking the data, accessing the pixel data requires the creation of a copy of that data in memory. Changes to that data are not saved back to the Core Graphics image.

## See Also

[`var cgImage: CGImage?`](/documentation/AppKit/NSBitmapImageRep/cgImage)

A Core Graphics image object based on the bitmap image representation’s data.


---

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