Package apple.metalperformanceshaders

Class MPSImageLaplacianPyramid

  • All Implemented Interfaces:
    NSCoding, NSCopying, NSSecureCoding, NSObject
    Direct Known Subclasses:
    MPSImageLaplacianPyramidAdd, MPSImageLaplacianPyramidSubtract
    public class MPSImageLaplacianPyramid
extends MPSImagePyramid
    MPSImageLaplacianPyramid Laplacian pyramid levels are constructed as difference between the current source level and 2x interpolated version of the half-resolution source level immediately above it. LaplacianMipLevel[l] := GaussianMipLevel[l] – Interpolate(GaussianMipLevel[l + 1]) The Interpolate function is the classical 2x signal interpolation procedure applied to all color channels of the source mip-level in both dimensions. It is logically equivalent to the following two-step process : 1) Zero-stuffing (sometimes called "upsampling"). It is the process of interleaving source pixel values with zero values: dst.at(x, y) := src.at(x, y) if even(x) and even(y) else 0 2) Filtering (sometimes called "interpolation"). It is the same procedure as implemented by the MPSImageConvolution class, using filter weights provided by the initializer methods inherited from MPSImagePyramid. The source for Laplacian pyramid construction is typically produced by the Gaussian pyramid algorithm -- a closely related image processing technique, but the Laplacian pyramid construction itself makes no assumptions neither about the data stored in the source texture nor about the interpolation filter weights, so Gaussian pyramid is just a conventional name for the source texture. Please refer to the classical "The Laplacian Pyramid as a Compact Image Code" whitepaper by Burt & Anderson, originally published in 532 IEEE TRANSACTIONS ON COMMUNICATIONS, VOL. COM-3l, NO. 4, APRIL 1983 for more detailed discussion. Since the subtraction operation extends the value range of LaplacianMipLevelRaw relative to the value range of GaussianMipLevel (even for the case of normalized interpolation filter), in order to avoid unwanted range clamping when working with normalized texture types, laplacianBias and laplacianScale class properties specify point-wise linear mapping of the LaplacianMipLevelRaw result data into the value range of the destination texture : LaplacianRangeScale(pixel, laplacianBias, laplacianScale) := laplacianBias + pixel * laplacianScale, LaplacianMipLevelStored[j] := LaplacianRangeScale(LaplacianMipLevel[j], laplacianBias, laplacianScale), with the default values being laplacianBias = 0.0, laplacianScale = 1.0 Limitations of the current software revision : 1) In-place operation is not supported, e.g. source and destination textures need to have separate storage and can't be aliased. 2) The number of channels, bit depth and resolution of the source and destination textures need to match. 3) Values of the offset and clipRect properties are fixed to the defaults provided by MPSUnaryImageKernel (from which they are inherited), corresponding to no offset applied to the source and unbounded region of interest in every destination mip-level; all updates to these properties are ignored.

    • Constructor Detail

      • MPSImageLaplacianPyramid

        protected MPSImageLaplacianPyramid​(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()

      • getLaplacianBias

        public float getLaplacianBias()

      • getLaplacianScale

        public float getLaplacianScale()

      • hash_static

        public static long hash_static()

      • initWithCoderDevice

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

      • initWithDevice

        public MPSImageLaplacianPyramid initWithDevice​(java.lang.Object device)
        Description copied from class: MPSImagePyramid
        Initialize a downwards 5-tap image pyramid with the default filter kernel and device The filter kernel is the outer product of w = [ 1/16, 1/4, 3/8, 1/4, 1/16 ]^T, with itself
        Overrides:
        initWithDevice in class MPSImagePyramid
        Parameters:
        device - The device the filter will run on
        Returns:
        A valid object or nil, if failure.

      • initWithDeviceCenterWeight

        public MPSImageLaplacianPyramid initWithDeviceCenterWeight​(MTLDevice device,
                                                           float centerWeight)
        Description copied from class: MPSImagePyramid
        Initialize a downwards 5-tap image pyramid with a central weight parameter and device
        Overrides:
        initWithDeviceCenterWeight in class MPSImagePyramid
        Parameters:
        device - The device the filter will run on
        centerWeight - Defines form of the filter-kernel through the outer product ww^T, where w = [ (1/4 - a/2), 1/4, a, 1/4, (1/4 - a/2) ]^T and 'a' is centerWeight.
        Returns:
        A valid object or nil, if failure.

      • initWithDeviceKernelWidthKernelHeightWeights

        public MPSImageLaplacianPyramid initWithDeviceKernelWidthKernelHeightWeights​(MTLDevice device,
                                                                             long kernelWidth,
                                                                             long kernelHeight,
                                                                             org.moe.natj.general.ptr.ConstFloatPtr kernelWeights)
        Description copied from class: MPSImagePyramid
        Initialize a downwards n-tap pyramid with a custom filter kernel and device
        Overrides:
        initWithDeviceKernelWidthKernelHeightWeights in class MPSImagePyramid
        Parameters:
        device - The device the filter will run on
        kernelWidth - The width of the filtering kernel. See @ref MPSImageConvolution.
        kernelHeight - The height of the filtering kernel. See @ref MPSImageConvolution.
        kernelWeights - A pointer to an array of kernelWidth * kernelHeight values to be used as the kernel. These are in row major order. See @ref MPSImageConvolution.
        Returns:
        A valid 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)

      • setLaplacianBias

        public void setLaplacianBias​(float value)

      • setLaplacianScale

        public void setLaplacianScale​(float value)

      • setVersion_static

        public static void setVersion_static​(long aVersion)

      • 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 MPSImagePyramid

      • version_static

        public static long version_static()