用另一种颜色替换图像中的特定颜色
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【中文标题】用另一种颜色替换图像中的特定颜色【英文标题】：Replace a particular color inside an image with another color 【发布时间】：2011-08-24 07:06:45 【问题描述】：我有一个“房间”图像。
现在，用户将单击图像中的任何特定颜色，假设为蓝色。
用户也会选择替换颜色，如“黑色”颜色。
因此，图像内的所有“蓝色”颜色都将替换为“黑色”颜色。
有人知道如何在 iPhone 中实现这一点吗？
感谢您的帮助。
【问题讨论】：
是的，完美的颜色替换是可能的，但它实际上不适用于现实世界的视频数据。有关更多信息和真正的解决方案，请参阅此问题：***.com/questions/18452808/… 【参考方案1】：-
您必须遍历图像中的每个像素并获取其 rgb
价值观
检查其 rgb 值是否与您的 fromColor rgb 值匹配，如果是的话
将像素值更改为您的 toColor rgb 值。如果没有，请离开
该像素并转到下一个..
凭记忆写了一个函数..可能有错误..自己改正
-(UIImage*)changeColor:(UIImage*)myImage fromColor:(UIColor*)fromColor toColor:(UIColor*)toColor
CGImageRef originalImage = [myImage CGImage];
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef bitmapContext =
CGBitmapContextCreate(NULL,CGImageGetWidth(originalImage),CGImageGetHeight(originalImage),
8,CGImageGetWidth(originalImage)*4,colorSpace,kCGImageAlphaPremultipliedLast);
CGColorSpaceRelease(colorSpace);
CGContextDrawImage(bitmapContext, CGRectMake(0, 0,
CGBitmapContextGetWidth(bitmapContext),CGBitmapContextGetHeight(bitmapContext)),
originalImage);
UInt8 *data = CGBitmapContextGetData(bitmapContext);
int numComponents = 4;
int bytesInContext = CGBitmapContextGetHeight(bitmapContext) *
CGBitmapContextGetBytesPerRow(bitmapContext);
double redIn, greenIn, blueIn,alphaIn;
CGFloat fromRed,fromGreen,fromBlue,fromAlpha;
CGFloat toRed,toGreen,toBlue,toAlpha;
//Get RGB values of fromColor
int fromCountComponents = CGColorGetNumberOfComponents([fromColor CGColor]);
if (fromCountComponents == 4)
const CGFloat *_components = CGColorGetComponents([fromColor CGColor]);
fromRed = _components[0];
fromGreen = _components[1];
fromBlue = _components[2];
fromAlpha = _components[3];
//Get RGB values for toColor
int toCountComponents = CGColorGetNumberOfComponents([toColor CGColor]);
if (toCountComponents == 4)
const CGFloat *_components = CGColorGetComponents([toColor CGColor]);
toRed = _components[0];
toGreen = _components[1];
toBlue = _components[2];
toAlpha = _components[3];
//Now iterate through each pixel in the image..
for (int i = 0; i < bytesInContext; i += numComponents)
//rgba value of current pixel..
redIn = (double)data[i]/255.0;
greenIn = (double)data[i+1]/255.0;
blueIn = (double)data[i+2]/255.0;
alphaIn = (double)data[i+3]/255.0;
//now you got current pixel rgb values...check it curresponds with your fromColor
if( redIn == fromRed && greenIn == fromGreen && blueIn == fromBlue )
//image color matches fromColor, then change current pixel color to toColor
data[i] = toRed;
data[i+1] = toGreen;
data[i+2] = toBlue;
data[i+3] = toAlpha;
CGImageRef outImage = CGBitmapContextCreateImage(bitmapContext);
myImage = [UIImage imageWithCGImage:outImage];
CGImageRelease(outImage);
return myImage;
我希望你不要每次都调用这个函数......它有点重处理器......如果我是你的处理器，我不会对你满意......:)
【讨论】：
对我有用。颜色没有任何变化 @Shailesh，这段代码是几年前编写的，当时还没有适用于 ios 的原生图像过滤库。 iOS 现在有核心图像框架，这可能是你应该研究的。 是的..我正在这样做。顺便说一句..这是我发布的问题。 ***.com/questions/27482508/…如果您能提供帮助，我将不胜感激 @Shailesh 我很乐意提供帮助。但在过去的 3 年里我没有接触过 iOS 开发。我得先重新学习 好的。我想我会找到解决办法的。如果可能的话，我会在这里发布解决方案。由于网络上没有太多关于此问题的材料【参考方案2】：我在寻找用另一种颜色替换颜色时偶然发现了这个答案。 好吧，既然我需要 Swift 代码，我已经尝试了几次，我找到了一个不错的解决方案。感谢@Rob 的answer。
extension UIImageView
@discardableResult func replace(color: UIColor, withColor replacingColor: UIColor) -> Bool
guard let inputCGImage = self.image?.cgImage else
return false
let colorSpace = CGColorSpaceCreateDeviceRGB()
let width = inputCGImage.width
let height = inputCGImage.height
let bytesPerPixel = 4
let bitsPerComponent = 8
let bytesPerRow = bytesPerPixel * width
let bitmapInfo = RGBA32.bitmapInfo
guard let context = CGContext(data: nil, width: width, height: height, bitsPerComponent: bitsPerComponent, bytesPerRow: bytesPerRow, space: colorSpace, bitmapInfo: bitmapInfo) else
print("unable to create context")
return false
context.draw(inputCGImage, in: CGRect(x: 0, y: 0, width: width, height: height))
guard let buffer = context.data else
return false
let pixelBuffer = buffer.bindMemory(to: RGBA32.self, capacity: width * height)
let inColor = RGBA32(color: color)
let outColor = RGBA32(color: replacingColor)
for row in 0 ..< Int(height)
for column in 0 ..< Int(width)
let offset = row * width + column
if pixelBuffer[offset] == inColor
pixelBuffer[offset] = outColor
guard let outputCGImage = context.makeImage() else
return false
self.image = UIImage(cgImage: outputCGImage, scale: self.image!.scale, orientation: self.image!.imageOrientation)
return true
其中 RGBA32 结构很简单：
struct RGBA32: Equatable
private var color: UInt32
var redComponent: UInt8
return UInt8((self.color >> 24) & 255)
var greenComponent: UInt8
return UInt8((self.color >> 16) & 255)
var blueComponent: UInt8
return UInt8((self.color >> 8) & 255)
var alphaComponent: UInt8
return UInt8((self.color >> 0) & 255)
init(red: UInt8, green: UInt8, blue: UInt8, alpha: UInt8)
self.color = (UInt32(red) << 24) | (UInt32(green) << 16) | (UInt32(blue) << 8) | (UInt32(alpha) << 0)
init(color: UIColor)
let components = color.cgColor.components ?? [0.0, 0.0, 0.0, 1.0]
let colors = components.map UInt8($0 * 255)
self.init(red: colors[0], green: colors[1], blue: colors[2], alpha: colors[3])
static let bitmapInfo = CGImageAlphaInfo.premultipliedLast.rawValue | CGBitmapInfo.byteOrder32Little.rawValue
static func ==(lhs: RGBA32, rhs: RGBA32) -> Bool
return lhs.color == rhs.color
这样，在你的代码中的任何地方：
let imageView = UIImageView()
let image = UIImage(color: .red) // (*)
imageView.image = image
imageView.replace(color: .red, withColor: .green)
(*) 用颜色创建图像解释here。
【讨论】：
【参考方案3】：您需要以某种方式访问原始像素数据（请参阅this answer 或用户 Krishnabhadra 的代码）。搜索所有像素，例如蓝色->黑色替换，用黑色替换所有蓝色像素。看看将颜色转换为 HSV，这将使颜色替换计算更容易。
【讨论】：
【参考方案4】：我修改了一些 Krishnabhadra 的代码，因为我使用 RGB 进行颜色输入和输出，例如：
[UIColor colorWithRed:191.0f/255.0f green:30.0f/255.0f blue:45.0f/255.0f alpha:1.0f]
为我工作。
-(UIImage*)changeColor:(UIImage*)myImage fromColor:(UIColor*)fromColor toColor:(UIColor*)toColor
CGImageRef originalImage = [myImage CGImage];
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef bitmapContext =
CGBitmapContextCreate(NULL,CGImageGetWidth(originalImage),CGImageGetHeight(originalImage),
8,CGImageGetWidth(originalImage)*4,colorSpace,kCGImageAlphaPremultipliedLast);
CGColorSpaceRelease(colorSpace);
CGContextDrawImage(bitmapContext, CGRectMake(0, 0,
CGBitmapContextGetWidth(bitmapContext),CGBitmapContextGetHeight(bitmapContext)),
originalImage);
UInt8 *data = CGBitmapContextGetData(bitmapContext);
int numComponents = 4;
int bytesInContext = CGBitmapContextGetHeight(bitmapContext) *
CGBitmapContextGetBytesPerRow(bitmapContext);
double redIn, greenIn, blueIn,alphaIn;
CGFloat fromRed,fromGreen,fromBlue,fromAlpha;
CGFloat toRed,toGreen,toBlue,toAlpha;
//Get RGB values of fromColor
int fromCountComponents = CGColorGetNumberOfComponents([fromColor CGColor]);
if (fromCountComponents == 4)
const CGFloat *_components = CGColorGetComponents([fromColor CGColor]);
fromRed = _components[0];
fromGreen = _components[1];
fromBlue = _components[2];
fromAlpha = _components[3];
//Get RGB values for toColor
int toCountComponents = CGColorGetNumberOfComponents([toColor CGColor]);
if (toCountComponents == 4)
const CGFloat *_components = CGColorGetComponents([toColor CGColor]);
toRed = _components[0]*255;
toGreen = _components[1]*255;
toBlue = _components[2]*255;
toAlpha = _components[3]*255;
//Now iterate through each pixel in the image..
for (int i = 0; i < bytesInContext; i += numComponents)
//rgba value of current pixel..
redIn = (double)data[i];
greenIn = (double)data[i+1];
blueIn = (double)data[i+2];
alphaIn = (double)data[i+3];
//now you got current pixel rgb values...check it curresponds with your fromColor
if( redIn == fromRed && greenIn == fromGreen && blueIn == fromBlue && alphaIn != 0 )
//image color matches fromColor, then change current pixel color to toColor
data[i] = toRed;
data[i+1] = toGreen;
data[i+2] = toBlue;
data[i+3] = toAlpha;
CGImageRef outImage = CGBitmapContextCreateImage(bitmapContext);
myImage = [UIImage imageWithCGImage:outImage];
CGImageRelease(outImage);
return myImage;
【讨论】：
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