Package apple.metalperformanceshaders

Class MPSCNNPoolingAverageGradient

  • All Implemented Interfaces:
    NSCoding, NSCopying, NSSecureCoding, NSObject
    public class MPSCNNPoolingAverageGradient
extends MPSCNNPoolingGradient
    MPSCNNPoolingAverageGradient [@dependency] This depends on Metal.framework Specifies the filter for computing the gradient of the average pooling filter. The operation backpropagates a gradient vector using chain rule. Average pooling forward pass is defined as: out(x) = sum_{dx \in Window(x)} in(s*x+dx) / N(x), where the pooling window definition 'Window(x)' follows MPSCNNPooling specification, 'N(x)' is effective pooling window size in pixels as specified in MPSCNNPoolingAverage, 's' is the pixel stride and in() is the source input image. Hence the partial derivative of the output value wrt. to the input value needed in the gradient backpropagation in MPSCNNPoolingGradient is: d out(x)/d in(y) = sum_{dx \in Window(x)} delta_{s*x+dx, y} / N(x), where delta_{x,y} is the Kronecker delta symbol for which delta_{x,y} = { 1, when x == y { 0, otherwise. In practice this means that the gradient value for the destination image at pixel 'x' is the sum over these contributions coming from all pooling windows that contribute to the average pooling computation in the forward pass, multiplied by the input gradient value in the source area of the corresponding pooling window. Note: As average pooling is a linear operation of its inputs, the gradient does not depend at all on the original input values, but the original input image size is needed so that we know the limits where the input values seize to exist to inhibit accumulation of gradient values for those pixels. Therefore, as secondary input, any correctly sized image will produce correct results for the gradient backpropagation and hence it is recommended to use a temporary image of correct size (see MPSTemporaryImage) for the secondary source image parameter.

    • Constructor Detail

      • MPSCNNPoolingAverageGradient

        protected MPSCNNPoolingAverageGradient​(org.moe.natj.general.Pointer peer)

    • Method Detail

      • accessInstanceVariablesDirectly

        public static boolean accessInstanceVariablesDirectly()

      • allocWithZone

        public static java.lang.Object allocWithZone​(org.moe.natj.general.ptr.VoidPtr zone)

      • automaticallyNotifiesObserversForKey

        public static boolean automaticallyNotifiesObserversForKey​(java.lang.String key)

      • cancelPreviousPerformRequestsWithTarget

        public static void cancelPreviousPerformRequestsWithTarget​(java.lang.Object aTarget)

      • cancelPreviousPerformRequestsWithTargetSelectorObject

        public static void cancelPreviousPerformRequestsWithTargetSelectorObject​(java.lang.Object aTarget,
                                                                         org.moe.natj.objc.SEL aSelector,
                                                                         java.lang.Object anArgument)

      • classFallbacksForKeyedArchiver

        public static NSArray<java.lang.String> classFallbacksForKeyedArchiver()

      • classForKeyedUnarchiver

        public static org.moe.natj.objc.Class classForKeyedUnarchiver()

      • debugDescription_static

        public static java.lang.String debugDescription_static()

      • description_static

        public static java.lang.String description_static()

      • hash_static

        public static long hash_static()

      • initWithCoderDevice

        public MPSCNNPoolingAverageGradient initWithCoderDevice​(NSCoder aDecoder,
                                                        java.lang.Object device)
        NSSecureCoding compatability See @ref MPSKernel#initWithCoder.
        Overrides:
        initWithCoderDevice in class MPSCNNPoolingGradient
        Parameters:
        aDecoder - The NSCoder subclass with your serialized MPSCNNPoolingAverageGradient
        device - The MTLDevice on which to make the MPSCNNPoolingAverageGradient
        Returns:
        A new MPSCNNPoolingAverageGradient object, or nil if failure.

      • initWithDevice

        public MPSCNNPoolingAverageGradient initWithDevice​(java.lang.Object device)
        Description copied from class: MPSCNNGradientKernel
        Standard init with default properties per filter type
        Overrides:
        initWithDevice in class MPSCNNPoolingGradient
        Parameters:
        device - The device that the filter will be used on. May not be NULL.
        Returns:
        A pointer to the newly initialized object. This will fail, returning nil if the device is not supported. Devices must be MTLFeatureSet_iOS_GPUFamily2_v1 or later.

      • initWithDeviceKernelWidthKernelHeight

        public MPSCNNPoolingAverageGradient initWithDeviceKernelWidthKernelHeight​(MTLDevice device,
                                                                          long kernelWidth,
                                                                          long kernelHeight)
        Description copied from class: MPSCNNPoolingGradient
        Initialize a gradient pooling filter
        Overrides:
        initWithDeviceKernelWidthKernelHeight in class MPSCNNPoolingGradient
        Parameters:
        device - The device the filter will run on
        kernelWidth - The width of the kernel. Can be an odd or even value.
        kernelHeight - The height of the kernel. Can be an odd or even value.
        Returns:
        A valid MPSCNNPoolingGradient object or nil, if failure.

      • initWithDeviceKernelWidthKernelHeightStrideInPixelsXStrideInPixelsY

        public MPSCNNPoolingAverageGradient initWithDeviceKernelWidthKernelHeightStrideInPixelsXStrideInPixelsY​(MTLDevice device,
                                                                                                        long kernelWidth,
                                                                                                        long kernelHeight,
                                                                                                        long strideInPixelsX,
                                                                                                        long strideInPixelsY)
        Initialize a gradient average pooling filter
        Overrides:
        initWithDeviceKernelWidthKernelHeightStrideInPixelsXStrideInPixelsY in class MPSCNNPoolingGradient
        Parameters:
        device - The device the filter will run on
        kernelWidth - The width of the kernel. Can be an odd or even value.
        kernelHeight - The height of the kernel. Can be an odd or even value.
        strideInPixelsX - The input stride (upsampling factor) in the x dimension.
        strideInPixelsY - The input stride (upsampling factor) in the y dimension.
        Returns:
        A valid MPSCNNPoolingGradient object or nil, if failure.

      • instanceMethodSignatureForSelector

        public static NSMethodSignature instanceMethodSignatureForSelector​(org.moe.natj.objc.SEL aSelector)

      • instancesRespondToSelector

        public static boolean instancesRespondToSelector​(org.moe.natj.objc.SEL aSelector)

      • isSubclassOfClass

        public static boolean isSubclassOfClass​(org.moe.natj.objc.Class aClass)

      • keyPathsForValuesAffectingValueForKey

        public static NSSet<java.lang.String> keyPathsForValuesAffectingValueForKey​(java.lang.String key)

      • new_objc

        public static java.lang.Object new_objc()

      • resolveClassMethod

        public static boolean resolveClassMethod​(org.moe.natj.objc.SEL sel)

      • resolveInstanceMethod

        public static boolean resolveInstanceMethod​(org.moe.natj.objc.SEL sel)

      • setVersion_static

        public static void setVersion_static​(long aVersion)

      • setZeroPadSizeX

        public void setZeroPadSizeX​(long value)
        [@property] zeroPadSizeX How much zero padding to apply to both left and right borders of the input image for average pooling, when using @see edgeMode MPSImageEdgeModeClamp. For @see edgeMode MPSImageEdgeModeZero this property is ignored and the area outside the image is interpreted to contain zeros. The zero padding size is used to shrink the pooling window to fit inside the area bound by the source image and its padding region, but the effect is that the normalization factor of the average computation is computed also for the zeros in the padding region.

      • setZeroPadSizeY

        public void setZeroPadSizeY​(long value)
        [@property] zeroPadSizeY How much zero padding to apply to both top and bottom borders of the input image for average pooling, when using @see edgeMode MPSImageEdgeModeClamp. For @see edgeMode MPSImageEdgeModeZero this property is ignored and the area outside the image is interpreted to contain zeros. The zero padding size is used to shrink the pooling window to fit inside the area bound by the source image and its padding region, but the effect is that the normalization factor of the average computation is computed also for the zeros in the padding region.

      • superclass_static

        public static org.moe.natj.objc.Class superclass_static()

      • supportsSecureCoding

        public static boolean supportsSecureCoding()

      • _supportsSecureCoding

        public boolean _supportsSecureCoding()
        Description copied from interface: NSSecureCoding
        This property must return YES on all classes that allow secure coding. Subclasses of classes that adopt NSSecureCoding and override initWithCoder: must also override this method and return YES. The Secure Coding Guide should be consulted when writing methods that decode data.
        Specified by:
        _supportsSecureCoding in interface NSSecureCoding
        Overrides:
        _supportsSecureCoding in class MPSCNNPoolingGradient

      • version_static

        public static long version_static()

      • zeroPadSizeX

        public long zeroPadSizeX()
        [@property] zeroPadSizeX How much zero padding to apply to both left and right borders of the input image for average pooling, when using @see edgeMode MPSImageEdgeModeClamp. For @see edgeMode MPSImageEdgeModeZero this property is ignored and the area outside the image is interpreted to contain zeros. The zero padding size is used to shrink the pooling window to fit inside the area bound by the source image and its padding region, but the effect is that the normalization factor of the average computation is computed also for the zeros in the padding region.

      • zeroPadSizeY

        public long zeroPadSizeY()
        [@property] zeroPadSizeY How much zero padding to apply to both top and bottom borders of the input image for average pooling, when using @see edgeMode MPSImageEdgeModeClamp. For @see edgeMode MPSImageEdgeModeZero this property is ignored and the area outside the image is interpreted to contain zeros. The zero padding size is used to shrink the pooling window to fit inside the area bound by the source image and its padding region, but the effect is that the normalization factor of the average computation is computed also for the zeros in the padding region.