CoreMLHelpers：为多数组转换创建图像的二进制数据

Question

我们将此用于 CoreMLhelpers，以便将 UIImage 转换为 MultiArray，反之亦然。

链接：https://github.com/hollance/CoreMLHelpers.

我们找到了以下评论参考。

// cat.bin 包含 cat.jpg，保存为 [0,1) 范围内的双精度形状 // (3, 360, 480).将此二进制数据加载到新的 MLMultiArray 对象中。

因此，我们使用自定义图像并尝试创建 .bin 文件，如下所示。 但是我们没有得到想要的输出，我们可以看到在阴影中混合了多种颜色和绿色的猫图像。

任何人都可以在这里抛出一些光来传达什么是正确的吗？

感谢您的回复！

import UIKit

func createBinary() -> MLMultiArray? {
    guard let image = UIImage(named: “cat.jpg”) else {
      fatalError(“Failed to load image”)
    }
    // Convert image to pixel data
    guard let cgImage = image.cgImage else {
      fatalError(“Failed to get CGImage from resized image”)
    }
    let width = 480
    let height = 360
    let bytesPerPixel = 4
    let bytesPerRow = width * bytesPerPixel
    let colorSpace = CGColorSpaceCreateDeviceRGB()
    let bitmapInfo = CGBitmapInfo.byteOrder32Little.rawValue | CGImageAlphaInfo.premultipliedLast.rawValue
    var pixelData = Array<UInt8>(repeating: 0, count: width * height * bytesPerPixel)
    guard let context = CGContext(data: &pixelData, width: width, height: height, bitsPerComponent: 8, bytesPerRow: bytesPerRow, space: colorSpace, bitmapInfo: bitmapInfo) else {
      fatalError(“Failed to create CGContext”)
    }
    context.draw(cgImage, in: CGRect(x: 0, y: 0, width: width, height: height))

    // Convert pixel data to binary data
    var binaryData = NSMutableData()

    for y in 0..<height {
      for x in 0..<width {
        let index = y * width * bytesPerPixel + x * bytesPerPixel
        var red = Double(pixelData[index]) / 255.0
            var green = Double(pixelData[index + 1]) / 255.0
            var blue = Double(pixelData[index + 2]) / 255.0
        binaryData.append(UnsafeRawPointer(&red), length: MemoryLayout<Double>.size)
        binaryData.append(UnsafeRawPointer(&green), length: MemoryLayout<Double>.size)
        binaryData.append(UnsafeRawPointer(&blue), length: MemoryLayout<Double>.size)
      }
    }
    // Verify binary data shape
    let expectedShape = (3, 360, 480)
    let actualShape = (3, height, width)
    guard expectedShape == actualShape else {
      fatalError(“Unexpected binary data shape: \(actualShape), expected: \(expectedShape)“)
    }
    // Done
    print(“Binary data size: \(binaryData.count) bytes”)
    let ptr = UnsafeMutableRawPointer(mutating: (binaryData as NSData).bytes)
    return try? MLMultiArray(dataPointer: ptr,
                 shape: [3, 360, 480],
                 dataType: .double,
                 strides: [NSNumber(value: 360*480), 480, 1])
  }