NAME

MPSImageTent

SYNOPSIS

#import <MPSImageConvolution.h>

Inherits MPSImageBox.

Detailed Description

The box filter, while fast, may yield square-ish looking blur effects. However, multiple passes of the box filter tend to smooth out with each additional pass. For example, two 3-wide box blurs produces the same effective convolution as a 5-wide tent blur:

1   1   1


    1   1   1
+       1   1   1
=================
1   2   3   2   1

Addition passes tend to approximate a gaussian line shape.

The MPSImageTent convolves an image with a tent filter. These form a tent shape with incrementally increasing sides, for example:

1   2   3   2   1
1   2   1
2   4   2
1   2   1

Like the box filter, this arrangement allows for much faster algorithms, espcially for for larger blur radii but with a more pleasing appearance.

The tent blur is a separable filter. The implementation is aware of this and will act accordingly to give best performance for multi-dimensional blurs.

Author

Generated automatically by Doxygen for MetalPerformanceShaders.framework from the source code.