---
title: convolution7X7()
framework: coreimage
role: symbol
role_heading: Type Method
path: coreimage/cifilter-swift.class/convolution7x7()
---

# convolution7X7()

Applies a convolution 7 x 7 filter to the RGBA color components of an image.

## Declaration

```swift
class func convolution7X7() -> any CIFilter & CIConvolution
```

## Return Value

Return Value The modified image.

## Discussion

Discussion This method applies the convolution 7 x 7 filter to an image. The effect uses a 7 x 7 area surrounding an input pixel, the pixel itself, and those within a distance of 3 pixels horizontally and vertically. The effect repeats this for every pixel within the image. The work area is then combined with the weight property vector to produce the processed image. This filter differs from the convolutionRGB7X7() filter, which only processes the RGB components. The convolution 7 x 7 filter uses the following properties: note: When using a nonzero bias value, the output image has an infinite extent. You should crop the output image before attempting to render it. The following code creates a filter that highlights edges in the input image: func convolution7X7(inputImage: CIImage) -> CIImage? {     let convolutionFilter = CIFilter.convolution7X7()     convolutionFilter.inputImage = inputImage     let weights: [CGFloat] = [         0, 0, -1, -1, -1, 0, 0,         0, -1, -3, -3, -3, -1, 0,         -1, -3, 0, 7, 0, -3, -1,         -1, -3, 7, 25, 7, -3, -1,         -1, -3, 0, 7, 0, -3, -1,         0, -1, -3, -3, -3, -1, 0,         0, 0, -1, -1, -1, 0, 0     ]     let kernel = CIVector(values: weights, count: 49)     convolutionFilter.weights = kernel     convolutionFilter.bias = 0.0     return convolutionFilter.outputImage! }

## See Also

### Filters

- [convolution3X3()](coreimage/cifilter-swift.class/convolution3x3().md)
- [convolution5X5()](coreimage/cifilter-swift.class/convolution5x5().md)
- [convolution9Horizontal()](coreimage/cifilter-swift.class/convolution9horizontal().md)
- [convolution9Vertical()](coreimage/cifilter-swift.class/convolution9vertical().md)
- [convolutionRGB3X3()](coreimage/cifilter-swift.class/convolutionrgb3x3().md)
- [convolutionRGB5X5()](coreimage/cifilter-swift.class/convolutionrgb5x5().md)
- [convolutionRGB7X7()](coreimage/cifilter-swift.class/convolutionrgb7x7().md)
- [convolutionRGB9Horizontal()](coreimage/cifilter-swift.class/convolutionrgb9horizontal().md)
- [convolutionRGB9Vertical()](coreimage/cifilter-swift.class/convolutionrgb9vertical().md)