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ios - 使用滑块更改图像的对比度和亮度

问题描述

我正在尝试使用滑块更改图像的对比度和亮度，并且我以编程方式创建了一个滑块。当我尝试通过滑块改变对比度时，出现类似错误

原因：'-[UISlider floatValue]：无法识别的选择器发送到实例 0x103c4ffa0'`func viewforslide(){ view.frame = CGRect.init(x: 10, y:view.frame.size.height - 180, width: self. view.frame.size.width - 20, height: 40) view.backgroundColor = UIColor.lightGray view.layer.cornerRadius = view.frame.size.height/2 view.addSubview(view) createlider() }

func createslider(){
    var sliderDemo = UISlider(frame:CGRect(x: 15, y: 5, width: vieew.frame.size.width - 30, height: 30))
    sliderDemo.minimumValue = 0.0
    sliderDemo.maximumValue = 1000.0
    sliderDemo.isContinuous = true
    sliderDemo.tintColor = UIColor.black
    sliderDemo.value = 500.0
    sliderDemo.addTarget(self, action:  #selector(_sldComponentChangedValue),for: .valueChanged)
    vieew.addSubview(sliderDemo)
}


@IBAction func _sldComponentChangedValue(sender: UISlider) {
  //  Set value to the nearest int
    sender.setValue(Float(roundf(sender.value)), animated: false)
    let newvalforslider = sender
    print("\(newvalforslider)")

    let displayinPercentage: Int = Int((sender.value/200) * 10000)
  //  contrastValueLabel.text = ("\(displayinPercentage)")
    self.imageView.image = results.enhancedImage
    let beginImage = CIImage(image: self.imageView.image!)
    let filter = CIFilter(name: "CIColorControls")
    filter?.setValue(beginImage, forKey: kCIInputImageKey)
    filter?.setValue(sender.value, forKey: kCIInputContrastKey)
    var filteredImage = filter?.outputImage
    var context = CIContext(options: nil)
    imageView.image = UIImage(cgImage: context.createCGImage(filteredImage!, from: (filteredImage?.extent)!)!)
    var sliderValue = sender.value

}

`

如果有人帮助我做到这一点，那就太好了。提前致谢。

标签： iosswift4.2contrast

解决方案

@anisha 如果您使以前的 Ans 复杂化。试试这个新代码。

func increaseContrast(_ image: UIImage) -> UIImage {
    let inputImage = CIImage(image: image)!
    let parameters =
    [
       "inputContrast": NSNumber(value: 2) // set how many contrast you want  
    ]
    let outputImage = inputImage.applyingFilter("CIColorControls", 
         parameters: parameters)
    let context = CIContext(options: nil)
    let img = context.createCGImage(outputImage, from: outputImage.extent)!
    return UIImage(cgImage: img)
}

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