Package apple.metalperformanceshaders

Class MPSImageEDLines

  • All Implemented Interfaces:
    NSCoding, NSCopying, NSSecureCoding, NSObject
    public class MPSImageEDLines
extends MPSKernel
    MPSImageEDLines The MPSImageEDLInes class implements the EDLines line segmenting algorithm using edge-drawing (ED) described here https://ieeexplore.ieee.org/document/6116138 The EDLInes algorithm consists of 5 steps, the first 4 of which describe the ED algorithm: 1. Blur the source image using a Gaussian blur with a sigma parameter 2. Use horizontal and vertical Sobel filters to find a gradient magnitude and direction. G = sqrt(Sx^2 + Sy^2) G_ang = arctan(Sy / Sx) 3. Compute anchor points, points with a high probability of being edge pixels. Anchor points are local maxima, in the gradient image that lie on row and column multiples of the detailRatio. This parameter effectively downsamples the gradient image, and directly influences the density of anchor points. A larger detailRatio results in fewer fine grained details, leaving long, main lines. 4. Anchor points are traced in a forward and backward direction along the gradient direction, until the gradient falls below some gradientThreshold parameter or the edge of the image is reached. The paths traced become an edge map of the image. 5. Points in the edges are fit to a line), and extended along the edge until the line error crosses a lineErrorThreshold. Lines which are beyond a minimum length are labelled line segments and will be outputs of the algorithm.

    • Constructor Detail

      • MPSImageEDLines

        protected MPSImageEDLines​(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()

      • clipRectSource

        public MTLRegion clipRectSource()
        [@property] clipRectSource 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.

      • debugDescription_static

        public static java.lang.String debugDescription_static()

      • description_static

        public static java.lang.String description_static()

      • detailRatio

        public char detailRatio()
        [@property] detailRatio Read-write value used to set the detailRatio to use in the EDLines algorithm Default is 32

      • encodeToCommandBufferSourceTextureDestinationTextureEndpointBufferEndpointOffset

        public void encodeToCommandBufferSourceTextureDestinationTextureEndpointBufferEndpointOffset​(MTLCommandBuffer commandBuffer,
                                                                                             MTLTexture source,
                                                                                             MTLTexture dest,
                                                                                             MTLBuffer endpointBuffer,
                                                                                             long endpointOffset)
        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
        dest - A valid MTLTexture containing the destination image for the filter. If not nil, the output will be the edges found through the Edge Drawing algorithm.
        endpointBuffer - A valid MTLBuffer to receive the line segment count and endpoint results.
        endpointOffset - Byte offset into endpoint buffer at which to write the line segment endpoint results. Must be a multiple of 32 bytes. The total line segment count and the line segment endpoints are written to the endpoint buffer. The count is written as a uint32_t at the start of the buffer. The line segments are written to the endpoint buffer as start and end pixel coordinates of the segment. Coordinates are stored as unsigned short pairs, and a single line segment will consist of two pairs, or four total unsigned shorts. The endpoint buffer size must be >= 4 * maxLines * sizeof(unsigned short) + sizeof(uint32_t).

      • gaussianSigma

        public float gaussianSigma()
        [@property] sigma Read-only sigma value used in performing Gaussian blur of the image. Default is 2.0

      • gradientThreshold

        public float gradientThreshold()
        [@property] gradientThreshold Read-write value used to set the threshold for a pixel to be considered an edge Default is 0.2

      • hash_static

        public static long hash_static()

      • initWithCoderDevice

        public MPSImageEDLines 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 MPSKernel
        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.

      • initWithDevice

        public MPSImageEDLines initWithDevice​(java.lang.Object device)
        Description copied from class: MPSKernel
        Standard init with default properties per filter type
        Overrides:
        initWithDevice in class MPSKernel
        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.

      • initWithDeviceGaussianSigmaMinLineLengthMaxLinesDetailRatioGradientThresholdLineErrorThresholdMergeLocalityThreshold

        public MPSImageEDLines initWithDeviceGaussianSigmaMinLineLengthMaxLinesDetailRatioGradientThresholdLineErrorThresholdMergeLocalityThreshold​(MTLDevice device,
                                                                                                                                            float gaussianSigma,
                                                                                                                                            char minLineLength,
                                                                                                                                            long maxLines,
                                                                                                                                            char detailRatio,
                                                                                                                                            float gradientThreshold,
                                                                                                                                            float lineErrorThreshold,
                                                                                                                                            float mergeLocalityThreshold)
        Initialize an EDLines kernel on a given device with specified parameters. [@code] w(i) = 1/sqrt(2*pi*sigma) * exp(-i^2/2*sigma^2) [@endcode] If we take cut off at 1% of w(0) (max weight) beyond which weights are considered 0, we have [@code] ceil (sqrt(-log(0.01)*2)*sigma) ~ ceil(3.7*sigma) [@endcode] as rough estimate of filter width
        Parameters:
        device - The device the filter will run on
        gaussianSigma - The standard deviation of gaussian blur filter. Gaussian weight, centered at 0, at integer grid i is given as
        minLineLength - The minimum length of output line segments.
        maxLines - The maximum amount of lines for the EDLines algorithm to output. The size of the endpointBuffer supplied at encode must be >= maxLines * 4 * sizeof(unsigned short) + sizeof(uint32_t).
        detailRatio - The detailRatio to use in the EDLines algorithm, which inversely effects the number of anchor points
        gradientThreshold - Any pixel with a gradient below the gradientThreshold will not be considerd an edge
        lineErrorThreshold - The limit of how much error a line segment can have relative to the edge it represents
        mergeLocalityThreshold - Determines how many pixels apart two lines can deviate spatially and still be merged. This value is normalized to the diagonal length of the image.
        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)

      • lineErrorThreshold

        public float lineErrorThreshold()
        [@property] lineErrorThreshold Read-write value used to set the limit on error for a line segment relative to the edge it fits Default is 0.05

      • maxLines

        public long maxLines()
        [@property] maxLines Read-write value used to set the max number of line segments to be written out. The endpointBuffer at encode must be >= maxLines * 4 * sizeof(unsigned short) + sizeof(uint32_t). Default is 256

      • mergeLocalityThreshold

        public float mergeLocalityThreshold()
        [@property] mergeLocalityThreshold Read-write value used to set how many pixels apart two lines can deviate spatially and still be merged. Default is 0.0025

      • minLineLength

        public char minLineLength()
        [@property] minLineLength Read-write value used to set the minimum length of a line segment. Default is 32

      • 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)

      • setClipRectSource

        public void setClipRectSource​(MTLRegion value)
        [@property] clipRectSource 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.

      • setDetailRatio

        public void setDetailRatio​(char value)
        [@property] detailRatio Read-write value used to set the detailRatio to use in the EDLines algorithm Default is 32

      • setGradientThreshold

        public void setGradientThreshold​(float value)
        [@property] gradientThreshold Read-write value used to set the threshold for a pixel to be considered an edge Default is 0.2

      • setLineErrorThreshold

        public void setLineErrorThreshold​(float value)
        [@property] lineErrorThreshold Read-write value used to set the limit on error for a line segment relative to the edge it fits Default is 0.05

      • setMaxLines

        public void setMaxLines​(long value)
        [@property] maxLines Read-write value used to set the max number of line segments to be written out. The endpointBuffer at encode must be >= maxLines * 4 * sizeof(unsigned short) + sizeof(uint32_t). Default is 256

      • setMergeLocalityThreshold

        public void setMergeLocalityThreshold​(float value)
        [@property] mergeLocalityThreshold Read-write value used to set how many pixels apart two lines can deviate spatially and still be merged. Default is 0.0025

      • setMinLineLength

        public void setMinLineLength​(char value)
        [@property] minLineLength Read-write value used to set the minimum length of a line segment. Default is 32

      • 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 MPSKernel

      • version_static

        public static long version_static()