如何通过带有Swift的UISlider使用CIColorControls更改亮度，对比度和饱和度 [英] How to change Brightness, Contrast and Saturation using CIColorControls via UISlider with Swift
问题描述
我正在使用照片滤镜应用程序，如您所见，我添加了一项功能来调整对比度，亮度，饱和度和噪点。但是问题是它们独立工作，这意味着当我调整亮度时，例如，当我开始编辑对比度时，亮度会恢复为原始亮度。
I'm working on a Photo Filter App and as you can see I added a feature to adjust contrast, brightness, saturation, and noise. But the problem is they work independently, which means when I'm adjusting let's say brightness as soon as I start editing contrast, it returns to the original brightness.
这里是预览，当我将亮度最大化（图像变白），然后尝试调整其对比度并滑块会更改原始图像的对比度。
Here is a preview when I'm putting the brightness to the maximum (the image gets white) and then trying to adjust its contrast and the slider changes the contrast of an original image.
在这里，我能够抓住释放滑块并将其值放在原始图像上的瞬间，如您所见，在演示中，我将饱和度设置为0，然后将相同饱和度的对比度更改为0。
Here I was able to catch the moment of releasing the slider and putting its value on the original image and as you can see it works, on a demo I put saturation 0 and then change the contrast of the same saturated to 0 picture.
。
问题是，现在当我仅单击滑块而不更改其值时，它会将当前值加倍。例如，如果我将亮度5设置为饱和度10，并决定在点击亮度后立即对其进行调整，则亮度值就会翻倍，我不知道为什么。
这是一个示例。我只是单击滑块而不更改其值。
The problem is that now when I just click on the slider without changing its value it doubled the current value. For example, if I put the brightness 5 and the put saturation 10 and decided to adjust the brightness as soon as I click on brightness it is doubling its value I don't know why. Here is an example. I'm just clicking on slider without changing its value.
这是代码
@objc func sliderValueDidChange(_ sender: UISlider!) {
if sender.tag == 0 {
let displayinPercentage: Int = Int((sender.value/200) * 10000)
brightnessValueLabel.text = ("\(displayinPercentage)")
selectedPictureImageView.image = originalImage
let beginImage = CIImage(image: selectedPictureImageView.image!)
self.filter = CIFilter(name: "CIColorControls")
self.filter?.setValue(beginImage, forKey: kCIInputImageKey)
self.filter.setValue(sender.value, forKey: kCIInputBrightnessKey)
self.filteredImage = self.filter?.outputImage
selectedPictureImageView.image = UIImage(cgImage: self.context.createCGImage(self.filteredImage!, from: (self.filteredImage?.extent)!)!)
sliderValue = sender.value
} else if sender.tag == 1 {
let displayinPercentage: Int = Int((sender.value/200) * 10000)
contrastValueLabel.text = ("\(displayinPercentage)")
self.selectedPictureImageView.image = originalImage
let beginImage = CIImage(image: self.selectedPictureImageView.image!)
self.filter = CIFilter(name: "CIColorControls")
self.filter?.setValue(beginImage, forKey: kCIInputImageKey)
self.filter.setValue(sender.value, forKey: kCIInputContrastKey)
self.filteredImage = self.filter?.outputImage
self.selectedPictureImageView.image = UIImage(cgImage: self.context.createCGImage(self.filteredImage!, from: (self.filteredImage?.extent)!)!)
sliderValue = sender.value
} else if sender.tag == 2 {
let displayinPercentage: Int = Int((sender.value/200) * 10000)
saturationValueLabel.text = ("\(displayinPercentage)")
self.selectedPictureImageView.image = originalImage
let beginImage = CIImage(image: self.selectedPictureImageView.image!)
self.filter = CIFilter(name: "CIColorControls")
self.filter?.setValue(beginImage, forKey: kCIInputImageKey)
self.filter.setValue(sender.value, forKey: kCIInputSaturationKey)
self.filteredImage = self.filter?.outputImage
self.selectedPictureImageView.image = UIImage(cgImage: self.context.createCGImage(self.filteredImage!, from: (self.filteredImage?.extent)!)!)
sliderValue = sender.value
} else if sender.tag == 3 {
let displayinPercentage: Int = Int((sender.value/200) * 10000)
sharpenValueLabel.text = ("\(displayinPercentage)")
self.selectedPictureImageView.image = originalImage
let beginImage = CIImage(image: self.selectedPictureImageView.image!)
self.filter = CIFilter(name: "CIUnsharpMask")
self.filter?.setValue(beginImage, forKey: kCIInputImageKey)
self.filter.setValue(7, forKey: kCIInputRadiusKey)
self.filter.setValue(sender.value, forKey: kCIInputIntensityKey)
self.filteredImage = self.filter?.outputImage
self.selectedPictureImageView.image = UIImage(cgImage: self.context.createCGImage(self.filteredImage!, from: (self.filteredImage?.extent)!)!)
sliderValue = sender.value
}
}
@objc func sliderValueDidEnd(_ sender: UISlider!) {
if sender.tag == 0 {
originalImage = selectedPictureImageView.image
sender.value = sliderValue
print("Unpressed button slider value is \(sender.value)")
} else if sender.tag == 1 {
originalImage = selectedPictureImageView.image
sender.value = sliderValue
print("Unpressed button slider value is \(sender.value)")
} else if sender.tag == 2 {
originalImage = selectedPictureImageView.image
sender.value = sliderValue
print("Unpressed button slider value is \(sender.value)")
} else if sender.tag == 3 {
originalImage = selectedPictureImageView.image
sender.value = sliderValue
print("Unpressed button slider value is \(sender.value)")
}
}
我认为一切正常，只是对过滤器值进行了错误的计算。
I think that everything is working fine, I just did wrong calculations on filters values.
推荐答案
您的问题是，每次滑动滑块时，您都将滤镜应用于上一个滤镜的结果图像，而不是应用于原始图像。顺便说一句，如果仅在用户完成操作后创建CGImage，则可以在滑动UISlider时使过滤器具有更高的响应速度。您的代码应如下所示：
You problem is that every time you slide the slider you are applying the filter to the resulting image of the previous filter instead of applying it to the original image. Btw you can make your filter a lot more responsive when sliding the UISlider if you just create a CGImage once the user is finished. Your code should look like this:
let displayinPercentage = Int((sender.value/200) * 10000)
brightnessValueLabel.text = String(displayinPercentage)
let beginImage = CIImage(image: originalImage)
filter.setValue(beginImage, forKey: kCIInputImageKey)
filter.setValue(sender.value, forKey: kCIInputBrightnessKey)
if let ciimage = filter.outputImage {
filteredImage = ciimage
selectedPictureImageView.image = UIImage(ciImage: filteredImage)
}
这篇关于如何通过带有Swift的UISlider使用CIColorControls更改亮度，对比度和饱和度的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
