MPSImageHistogram(3)   MetalPerformanceShaders.framework  MPSImageHistogram(3)

NAME

       MPSImageHistogram

SYNOPSIS

       #import <MPSImageHistogram.h>

       Inherits MPSKernel.

   Instance Methods
       (nonnull instancetype) - initWithDevice:histogramInfo:
       (nullable instancetype) - initWithCoder:device:
       (void) - encodeToCommandBuffer:sourceTexture:histogram:histogramOffset:
       (size_t) - histogramSizeForSourceFormat:

   Properties
       MTLRegion clipRectSource
       BOOL zeroHistogram
       vector_float4 minPixelThresholdValue
       MPSImageHistogramInfo histogramInfo

   Additional Inherited Members

Detailed Description

       The MPSImageHistogram computes the histogram of an image.

Method Documentation

   - (void) encodeToCommandBuffer: (nonnull id< MTLCommandBuffer >)
       commandBuffer(nonnull id< MTLTexture >) source(nonnull id< MTLBuffer >)
       histogram(NSUInteger) histogramOffset
       Encode the filter to a command buffer using a MTLComputeCommandEncoder.
       The filter will not begin to execute until after the command buffer has
       been enqueued and committed.

       Parameters:
           commandBuffer A valid MTLCommandBuffer.
           source A valid MTLTexture containing the source image for the
           filter
           histogram A valid MTLBuffer to receive the histogram results.
           histogramOffset Byte offset into histogram buffer at which to write
           the histogram results. Must be a multiple of 32 bytes. The
           histogram results / channel are stored together. The number of
           channels for which histogram results are stored is determined by
           the number of channels in the image. If
           histogramInfo.histogramForAlpha is false and the source image is
           RGBA then only histogram results for RGB channels are stored.

       The histogram results are stored in the histogram buffer as follows:

       o histogram results for the R channel for all bins followed by

       o histogram results for the G channel for all bins followed by

       o histogram results for the B channel for all bins followed by

       o histogram results for the A channel for all bins



   - (size_t) histogramSizeForSourceFormat: (MTLPixelFormat) sourceFormat
       The amount of space in the output MTLBuffer the histogram will take up.
       This convenience function calculates the minimum amount of space needed
       in the output histogram for the results. The MTLBuffer should be at
       least this length, longer if histogramOffset is non-zero.

       Parameters:
           sourceFormat The MTLPixelFormat of the source image. This is the
           source parameter of -encodeToCommandBuffer:
           sourceTexture:histogram:histogramOffset

       Returns:
           The number of bytes needed to store the result histograms.



   - (nullable instancetype) initWithCoder: (NSCoder *__nonnull)
       aDecoder(nonnull id< MTLDevice >) device
       NSSecureCoding compatability  While the standard
       NSSecureCoding/NSCoding method -initWithCoder: should work, since the
       file can't know which device your data is allocated on, we have to
       guess and may guess incorrectly. To avoid that problem, use
       initWithCoder:device instead.

       Parameters:
           aDecoder The NSCoder subclass with your serialized MPSKernel
           device The MTLDevice on which to make the MPSKernel

       Returns:
           A new MPSKernel object, or nil if failure.



       Reimplemented from MPSKernel.

   - (nonnull instancetype) initWithDevice: (nonnull id< MTLDevice >)
       device(const MPSImageHistogramInfo *__nonnull) histogramInfo
       Specifies information to compute the histogram for channels of an
       image.

       Parameters:
           device The device the filter will run on
           histogramInfo Pointer to the MPSHistogramInfo struct

       Returns:
           A valid MPSImageHistogram object or nil, if failure.

Property Documentation

   - clipRectSource [read],  [write],  [nonatomic],  [assign]
       The source rectangle to use when reading data.  A MTLRegion that
       indicates which part of the source to read. If the clipRectSource does
       not lie completely within the source image, the intersection of the
       image bounds and clipRectSource will be used. The clipRectSource
       replaces the MPSUnaryImageKernel offset parameter for this filter. The
       latter is ignored. Default: MPSRectNoClip, use the entire source
       texture.

   - histogramInfo [read],  [nonatomic],  [assign]
       Return a structure describing the histogram content  Returns a
       MPSImageHistogramInfo structure describing the format of the histogram.

   - minPixelThresholdValue [read],  [write],  [nonatomic],  [assign]
       The minimum pixel threshold value  The histogram entries will be
       incremented only if pixel value is >= minPixelThresholdValue. The
       minPixelThresholdValue is a floating-point value. For unsigned
       normalized textures, the minPixelThresholdValue should be a value
       between 0.0f and 1.0f (for eg. MTLPixelFormatRGBA8Unorm). For signed
       normalized textures, the minPixelThresholdValue should be a value
       between -1.0f and 1.0f (for eg. MTLPixelFormatRGBA8Snorm). Default:
       vector_float4(0.0f).

   - zeroHistogram [read],  [write],  [nonatomic],  [assign]
       Zero-initalize the histogram results  Indicates that the memory region
       in which the histogram results are to be written in the histogram
       buffer are to be zero-initialized or not. Default: YES.

Author

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





Version MetalPerformanceShaders-Thu2Jul 13 2017           MPSImageHistogram(3)


Mac OS X 10.13.1 - Generated Tue Nov  7 07:18:58 CST 2017