Package apple.metalperformanceshaders

Class MPSCNNLocalContrastNormalization

  • All Implemented Interfaces:
    NSCoding, NSCopying, NSSecureCoding, NSObject
    public class MPSCNNLocalContrastNormalization
extends MPSCNNKernel
    MPSCNNLocalContrastNormalization [@dependency] This depends on Metal.framework Specifies the local contrast normalization filter. The local contrast normalization is quite similar to spatial normalization (see @ref MPSCNNSpatialNormalization) in that it applies the filter over local regions which extend spatially, but are in separate feature channels (i.e., they have shape 1 x kernelWidth x kernelHeight), but instead of dividing by the local "energy" of the feature, the denominator uses the local variance of the feature - effectively the mean value of the feature is subtracted from the signal. For each feature channel, the function computes the variance VAR(i,j) and mean M(i,j) of X(i,j) inside each rectangle around the spatial point (i,j). Then the result is computed for each element of X as follows: Y(i,j) = pm + ps * ( X(i,j) - p0 * M(i,j)) / (delta + alpha * VAR(i,j))^beta, where kw and kh are the kernelWidth and the kernelHeight and pm, ps and p0 are parameters that can be used to offset and scale the result in various ways. For example setting pm=0, ps=1, p0=1, delta=0, alpha=1.0 and beta=0.5 scales input data so that the result has unit variance and zero mean, provided that input variance is positive. It is the end-users responsibility to ensure that the combination of the parameters delta and alpha does not result in a situation where the denominator becomes zero - in such situations the resulting pixel-value is undefined. A good way to guard against tiny variances is to regulate the expression with a small value for delta, for example delta = 1/1024 = 0.0009765625.

    • Constructor Detail

      • MPSCNNLocalContrastNormalization

        protected MPSCNNLocalContrastNormalization​(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()

      • 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)

      • superclass_static

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

      • version_static

        public static long version_static()

      • alpha

        public float alpha()
        [@property] alpha The value of alpha. Default is 0.0 The default value 0.0 is not recommended and is preserved for backwards compatibility. With alpha 0, it performs a local mean subtraction. The MPSCNNLocalContrastNormalizationNode used with the MPSNNGraph uses 1.0 as a default.

      • beta

        public float beta()
        [@property] beta The value of beta. Default is 0.5

      • delta

        public float delta()
        [@property] delta The value of delta. Default is 1/1024

      • initWithDevice

        public MPSCNNLocalContrastNormalization initWithDevice​(java.lang.Object device)
        Description copied from class: MPSCNNKernel
        Standard init with default properties per filter type
        Overrides:
        initWithDevice in class MPSCNNKernel
        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 MPSCNNLocalContrastNormalization initWithDeviceKernelWidthKernelHeight​(MTLDevice device,
                                                                              long kernelWidth,
                                                                              long kernelHeight)
        Initialize a local contrast normalization filter
        Parameters:
        device - The device the filter will run on
        kernelWidth - The width of the kernel
        kernelHeight - The height of the kernel
        Returns:
        A valid MPSCNNLocalContrastNormalization object or nil, if failure. NOTE: For now, kernelWidth must be equal to kernelHeight

      • p0

        public float p0()
        [@property] p0 The value of p0. Default is 1.0

      • pm

        public float pm()
        [@property] pm The value of pm. Default is 0.0

      • ps

        public float ps()
        [@property] ps The value of ps. Default is 1.0

      • setAlpha

        public void setAlpha​(float value)
        [@property] alpha The value of alpha. Default is 0.0 The default value 0.0 is not recommended and is preserved for backwards compatibility. With alpha 0, it performs a local mean subtraction. The MPSCNNLocalContrastNormalizationNode used with the MPSNNGraph uses 1.0 as a default.

      • setBeta

        public void setBeta​(float value)
        [@property] beta The value of beta. Default is 0.5

      • setDelta

        public void setDelta​(float value)
        [@property] delta The value of delta. Default is 1/1024

      • setP0

        public void setP0​(float value)
        [@property] p0 The value of p0. Default is 1.0

      • setPm

        public void setPm​(float value)
        [@property] pm The value of pm. Default is 0.0

      • setPs

        public void setPs​(float value)
        [@property] ps The value of ps. Default is 1.0

      • initWithCoderDevice

        public MPSCNNLocalContrastNormalization initWithCoderDevice​(NSCoder aDecoder,
                                                            java.lang.Object 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.
        Overrides:
        initWithCoderDevice in class MPSCNNKernel
        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.

      • 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 MPSCNNKernel