将UIImage转换为8灰度像素缓冲区

我能够将UIImage转换为ARGB CVPixelBuffer，但现在我试图将UIImage转换为灰度级缓冲区。我想我就再没代码经历，但coreML模型笙歌说：将UIImage转换为8灰度像素缓冲区

“错误域= com.apple.CoreML代码= 1”图片预计不会式 8灰色，反而是不支持的（40）”

这里是灰度CGContext我到目前为止：

public func pixelBufferGray(width: Int, height: Int) -> CVPixelBuffer? { 

     var pixelBuffer : CVPixelBuffer? 
     let attributes = [kCVPixelBufferCGImageCompatibilityKey: kCFBooleanTrue, kCVPixelBufferCGBitmapContextCompatibilityKey: kCFBooleanTrue] 

     let status = CVPixelBufferCreate(kCFAllocatorDefault, Int(width), Int(height), kCVPixelFormatType_8IndexedGray_WhiteIsZero, attributes as CFDictionary, &pixelBuffer) 

     guard status == kCVReturnSuccess, let imageBuffer = pixelBuffer else { 
      return nil 
     } 

     CVPixelBufferLockBaseAddress(imageBuffer, CVPixelBufferLockFlags(rawValue: 0)) 

     let imageData = CVPixelBufferGetBaseAddress(imageBuffer) 

     guard let context = CGContext(data: imageData, width: Int(width), height:Int(height), 
             bitsPerComponent: 8, bytesPerRow: CVPixelBufferGetBytesPerRow(imageBuffer), 
             space: CGColorSpaceCreateDeviceGray(), 
             bitmapInfo: CGImageAlphaInfo.none.rawValue) else { 
             return nil 
     } 

     context.translateBy(x: 0, y: CGFloat(height)) 
     context.scaleBy(x: 1, y: -1) 

     UIGraphicsPushContext(context) 
     self.draw(in: CGRect(x:0, y:0, width: width, height: height)) 
     UIGraphicsPopContext() 
     CVPixelBufferUnlockBaseAddress(imageBuffer, CVPixelBufferLockFlags(rawValue: 0)) 

     return imageBuffer 

    }

任何帮助，将不胜感激

来源

2017-06-13 user1988824

当你创建这个代码上下文，您是否尝试用kCVPixelFormatType_8IndexedGray_WhiteIsZero或kCVPixelFormatType_8Indexed替换空格参数？ –

感谢您的帮助，正确的像素格式是kCVPixelFormatType_OneComponent8灰度UIImage – user1988824

你可能已经投了我的评论至少大声笑 –

即使图像称为灰度，正确的像素格式为：kCVPixelFormatType_OneComponent8

希望这个完整的代码片段将帮助别人一起：

public func pixelBufferGray(width: Int, height: Int) -> CVPixelBuffer? { 

     var pixelBuffer : CVPixelBuffer? 
     let attributes = [kCVPixelBufferCGImageCompatibilityKey: kCFBooleanTrue, kCVPixelBufferCGBitmapContextCompatibilityKey: kCFBooleanTrue] 

     let status = CVPixelBufferCreate(kCFAllocatorDefault, Int(width), Int(height), kCVPixelFormatType_OneComponent8, attributes as CFDictionary, &pixelBuffer) 

     guard status == kCVReturnSuccess, let imageBuffer = pixelBuffer else { 
      return nil 
     } 

     CVPixelBufferLockBaseAddress(imageBuffer, CVPixelBufferLockFlags(rawValue: 0)) 

     let imageData = CVPixelBufferGetBaseAddress(imageBuffer) 

     guard let context = CGContext(data: imageData, width: Int(width), height:Int(height), 
             bitsPerComponent: 8, bytesPerRow: CVPixelBufferGetBytesPerRow(imageBuffer), 
             space: CGColorSpaceCreateDeviceGray(), 
             bitmapInfo: CGImageAlphaInfo.none.rawValue) else { 
             return nil 
     } 

     context.translateBy(x: 0, y: CGFloat(height)) 
     context.scaleBy(x: 1, y: -1) 

     UIGraphicsPushContext(context) 
     self.draw(in: CGRect(x:0, y:0, width: width, height: height)) 
     UIGraphicsPopContext() 
     CVPixelBufferUnlockBaseAddress(imageBuffer, CVPixelBufferLockFlags(rawValue: 0)) 

     return imageBuffer 

    }

来源

2017-06-13 20:30:39 user1988824

将UIImage转换为8灰度像素缓冲区

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