ImageIO products trash log

Question

Created Sep ’21

Replies 1

Boosts 0

Participants 1

Hello everyone, It's a nice holiday. I changed pixel value from uiimage, so produce other image. Code is this.


   func normalize(_ image: UIImage) -> UIImage {
    let width = 320
    let height = 240
    let bytesPerComponent = 4
    let channel = 1
    let imageSize = width * height * bytesPerComponent

    guard Int(image.size.width) == width,
       Int(image.size.height) == height,
       image.cgImage?.bitsPerComponent == 8,
       image.cgImage?.bitsPerPixel == 8
    else { // setting include width, height type is uint8 and 1 channel
      fatalError("\(#function) : you should fixed image setting")
    }

    let cgimage = image.cgImage
    guard let originalData = cgimage?.dataProvider?.data,
       let original = CFDataGetBytePtr(originalData)
    else {
      fatalError("\(#function) : get original buffer failed.")
    }
     
    imageData = UnsafeMutablePointer<Float32>.allocate(capacity: width * height)
    guard let imageData = imageData else { fatalError("\(#function) : unknwon error") }

    // 0 ~ 255 (uint8) -> -1.0 ~ 1.0 (float32)
    let normValue: Float32 = 127.5
    for w in 0..<width {
      for h in 0..<height {
        imageData[h * width + w] = (Float32(original[h * width + w]) - normValue) / normValue
      }
    }

    guard let provider = CGDataProvider(data: Data(bytesNoCopy: imageData,
                            count: imageSize,
                            deallocator: .none) as CFData)
    else {
      fatalError("\(#function) : provider load failed.")
    }

    guard let cgImage = CGImage(width: width,
                  height: height,
                  bitsPerComponent: bytesPerComponent * 8,
                  bitsPerPixel: bytesPerComponent * channel * 8,
                  bytesPerRow: bytesPerComponent * channel * width,
                  space: CGColorSpaceCreateDeviceGray(),
                  bitmapInfo: CGBitmapInfo(rawValue: 0),
                  provider: provider,
                  decode: nil,
                  shouldInterpolate: false,
                  intent: .defaultIntent)
    else {
      fatalError("\(#function) : create cgimage failed by unknown error")
    }

    return UIImage(cgImage: cgImage)
  }

This code is done every frame, and produce this log, sometimes and logs are too much.

[Mars] mapData:843: *** ImageIO - mmapped file changed (old: 6782 new: 6875)

I don't know "843" mean and following number paste at tail of log, changed every times. I don't know it means warning or error and so on.

It works well, it seems no problem, But I worried about too many logs and thread problem. I just feel bad. Have you see this log anyone?

Boost

Answer 1

Wonki OP

Sep ’21

Accepted Answer

This problem is maybe about thread problem. I produce image from other thread and use image in main thread, this log is made. But use image in same thread, this log is disappear.

func detectHead(_ mat: MatPtr) -> IcpOnlyCondition {
    guard let image = cvMatToUIImageByFileIO(mat) else {
      return .auto
    }

    return detectHeadModel.prediction(image: image)
  }

Original

func detectHead(_ mat: MatPtr) -> IcpOnlyCondition {
    guard let image = cvMatToUIImageByFileIO(mat) else {
      return .auto
    }
   DispatchQueue.main.async {
       return detectHeadModel.prediction(image: image)
  }
}

1