Accelerate

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Make large-scale mathematical computations and image calculations with high-performance, energy-efficient computation using Accelerate.

Posts under Accelerate tag

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How to get the position of dominant colors in CGImage?
so, my app needs to find the dominant palette and the position in the image of the k-most dominant colors. I followed the very useful sample project from the vImage documentation https://developer.apple.com/documentation/accelerate/bnns/calculating_the_dominant_colors_in_an_image and the algorithm works fine although I can't wrap my head around how should I go on about and linking said colors with a point in the image. Since the algorithm works by filling storages first, I tried also filling an array of CGPoints called LocationStorage and working with that //filling the array for i in 0...width { for j in 0...height { locationStorage.append( CGPoint(x: i, y: j)) } . . . //working with the array let randomIndex = Int.random(in: 0 ..< width * height) centroids.append(Centroid(red: redStorage[randomIndex], green: greenStorage[randomIndex], blue: blueStorage[randomIndex], position: locationStorage[randomIndex])) } struct Centroid { /// The red channel value. var red: Float /// The green channel value. var green: Float /// The blue channel value. var blue: Float /// The number of pixels assigned to this cluster center. var pixelCount: Int = 0 var position: CGPoint = CGPointZero init(red: Float, green: Float, blue: Float, position: CGPoint) { self.red = red self.green = green self.blue = blue self.position = position } } although it's not accurate. I also tried force trying every pixel in the image to get as close to each color but I think it's too slow. What do you think my approach should be? Let me know if you need additional info Please be kind I'm learning Swift.
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996
Apr ’24
Scipy problems with OpenBLAS and Accelerate
I'm using M1pro and have successfully installed Numpy with Accelerate following, and it really speedup my programs. I also ran np.test() to check the correctness and every test passed. However, I can't install Scipy with Accelerate, since the official document said Accelerate has a LAPACK of too old version. I can't even find a scipy that can pass scipy.test(). I tried the codes below: conda install numpy 'libblas=*=*accelerate' conda install scipy np.test() as fails, sp.test() can't even finish conda install numpy 'libblas=*=*openblas' conda install scipy Both np.test() and sp.test() can finish, but with many failures. I believe the bugs are due to Conda. pip install --no-binary :all: --no-use-pep517 numpy pip install scipy np.test() has no failure and went fast, sp.test() uses OpenBLAS and has 3 failures. This is the best version I have found. So my question is: can we find a reliable version of scipy on M1? Considering the popularity of scipy, I think it's not a high-living expectation. And a question for Apple: is there really a plan to upgrade the LAPACK in Accelerate?
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2.4k
Jan ’25