答案 0 :(得分:11)
我无法在“重复”中找到任何答案。 (这个问题不应该被标记为重复),它可以让你用另一种颜色替换给定的颜色和在不透明的图像上工作,所以我决定添加一个。< /强>
我为此创建了一个UIImage
类别,它基本上是通过循环每个像素并检测它与给定颜色的接近程度,并将其与替换颜色混合(如果是的话)。
这适用于透明度和不透明背景的图像。
@implementation UIImage (UIImageColorReplacement)
-(UIImage*) imageByReplacingColor:(UIColor*)sourceColor withMinTolerance:(CGFloat)minTolerance withMaxTolerance:(CGFloat)maxTolerance withColor:(UIColor*)destinationColor {
// components of the source color
const CGFloat* sourceComponents = CGColorGetComponents(sourceColor.CGColor);
UInt8* source255Components = malloc(sizeof(UInt8)*4);
for (int i = 0; i < 4; i++) source255Components[i] = (UInt8)round(sourceComponents[i]*255.0);
// components of the destination color
const CGFloat* destinationComponents = CGColorGetComponents(destinationColor.CGColor);
UInt8* destination255Components = malloc(sizeof(UInt8)*4);
for (int i = 0; i < 4; i++) destination255Components[i] = (UInt8)round(destinationComponents[i]*255.0);
// raw image reference
CGImageRef rawImage = self.CGImage;
// image attributes
size_t width = CGImageGetWidth(rawImage);
size_t height = CGImageGetHeight(rawImage);
CGRect rect = {CGPointZero, {width, height}};
// bitmap format
size_t bitsPerComponent = 8;
size_t bytesPerRow = width*4;
CGBitmapInfo bitmapInfo = kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big;
// data pointer
UInt8* data = calloc(bytesPerRow, height);
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
// create bitmap context
CGContextRef ctx = CGBitmapContextCreate(data, width, height, bitsPerComponent, bytesPerRow, colorSpace, bitmapInfo);
CGContextDrawImage(ctx, rect, rawImage);
// loop through each pixel's components
for (int byte = 0; byte < bytesPerRow*height; byte += 4) {
UInt8 r = data[byte];
UInt8 g = data[byte+1];
UInt8 b = data[byte+2];
// delta components
UInt8 dr = abs(r-source255Components[0]);
UInt8 dg = abs(g-source255Components[1]);
UInt8 db = abs(b-source255Components[2]);
// ratio of 'how far away' each component is from the source color
CGFloat ratio = (dr+dg+db)/(255.0*3.0);
if (ratio > maxTolerance) ratio = 1; // if ratio is too far away, set it to max.
if (ratio < minTolerance) ratio = 0; // if ratio isn't far enough away, set it to min.
// blend color components
data[byte] = (UInt8)round(ratio*r)+(UInt8)round((1.0-ratio)*destination255Components[0]);
data[byte+1] = (UInt8)round(ratio*g)+(UInt8)round((1.0-ratio)*destination255Components[1]);
data[byte+2] = (UInt8)round(ratio*b)+(UInt8)round((1.0-ratio)*destination255Components[2]);
}
// get image from context
CGImageRef img = CGBitmapContextCreateImage(ctx);
// clean up
CGContextRelease(ctx);
CGColorSpaceRelease(colorSpace);
free(data);
free(source255Components);
free(destination255Components);
UIImage* returnImage = [UIImage imageWithCGImage:img];
CGImageRelease(img);
return returnImage;
}
@end
<强>用法:强>
UIImage* colaImage = [UIImage imageNamed:@"cola1.png"];
UIImage* blackColaImage = [colaImage imageByReplacingColor:[UIColor colorWithRed:1 green:0 blue:0 alpha:1] withMinTolerance:0.5 withMaxTolerance:0.6 withColor:[UIColor colorWithRed:0 green:0 blue:0 alpha:1]];
minTolerance
是像素开始与替换颜色混合(而不是被替换)的点。 maxTolerance
是像素停止混合的点。
<强>之前:强>
<强>后:强>
结果有点混淆,但请记住,您的原始图像相当小。对于更高分辨率的图像,这将更好地工作。您也可以使用公差来获得更好的结果!
答案 1 :(得分:0)
您可以使用此
theImageView.image = [image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
[theImageView setTintColor:[UIColor blackColor]];
答案 2 :(得分:0)
注意:首先,您需要使用Photoshop或任何其他工具将图像的背景设置为透明。
然后使用下面的代码。
简单的方法, 您需要使用渲染模式来更改此颜色。
cokeImageView.image = [image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate]; // yourimageviewname
[cokeImageView setTintColor:[UIColor blackColor]];