我有一张灰度图像，想用它来绘制Cocoa控件。该图像具有各种灰度级别。在最暗的地方，我希望它以指定的深色色调进行绘制。在源图像为白色的地方，它应该是透明的。
基本上，我想复制在iPhone上看到的UINavigationBar中tintColor的行为。
到目前为止，我已经尝试了几个选项：
使用SourceOver组合将着色色彩绘制在灰度图像上 -> 这需要一个非不透明的着色色彩 -> 结果比预期的要暗得多
使用CIMultiplyCompositing CIFilter来着色图像 -> 我无法使用[CIImage drawAtPoint:fromRect:operation:fraction:]仅绘制图像的一部分，但同样适用于NSImage -> 我偶尔会遇到无法理解的崩溃
将灰度图像转换为掩模。即，黑色应该是不透明的。白色应该是透明的。灰色应该具有中间的alpha值。 -> 这似乎是最好的解决方案 -> 尽管我努力尝试，但无法实现
上面的解决方案对我没用。但是这个更简单的解决方案对我非常有效。
- (NSImage *)imageTintedWithColor:(NSColor *)tint
{
NSImage *image = [self copy];
if (tint) {
[image lockFocus];
[tint set];
NSRect imageRect = {NSZeroPoint, [image size]};
NSRectFillUsingOperation(imageRect, NSCompositeSourceIn);
[image unlockFocus];
}
return image;
}
NSImage lockFocus 在 macOS 13.0 版本之后已被弃用。 - HangarRash一个 Swift 实现 bluebamboo 的答案：
func tintedImage(_ image: NSImage, tint: NSColor) -> NSImage {
guard let tinted = image.copy() as? NSImage else { return image }
tinted.lockFocus()
tint.set()
let imageRect = NSRect(origin: NSZeroPoint, size: image.size)
NSRectFillUsingOperation(imageRect, .sourceAtop)
tinted.unlockFocus()
return tinted
}
imageRect.fill(using:)。 - Jeeter.sourceIn来正确地进行着色，特别是如果你想用较浅的色调替换原始颜色。 - strangetimesNSImage lockFocus 在 macOS 13.0 中已被弃用。 - HangarRash- (NSImage *)imageTintedWithColor:(NSColor *)tint
{
if (tint != nil) {
NSSize size = [self size];
NSRect bounds = { NSZeroPoint, size };
NSImage *tintedImage = [[NSImage alloc] initWithSize:size];
[tintedImage lockFocus];
CIFilter *colorGenerator = [CIFilter filterWithName:@"CIConstantColorGenerator"];
CIColor *color = [[[CIColor alloc] initWithColor:tint] autorelease];
[colorGenerator setValue:color forKey:@"inputColor"];
CIFilter *monochromeFilter = [CIFilter filterWithName:@"CIColorMonochrome"];
CIImage *baseImage = [CIImage imageWithData:[self TIFFRepresentation]];
[monochromeFilter setValue:baseImage forKey:@"inputImage"];
[monochromeFilter setValue:[CIColor colorWithRed:0.75 green:0.75 blue:0.75] forKey:@"inputColor"];
[monochromeFilter setValue:[NSNumber numberWithFloat:1.0] forKey:@"inputIntensity"];
CIFilter *compositingFilter = [CIFilter filterWithName:@"CIMultiplyCompositing"];
[compositingFilter setValue:[colorGenerator valueForKey:@"outputImage"] forKey:@"inputImage"];
[compositingFilter setValue:[monochromeFilter valueForKey:@"outputImage"] forKey:@"inputBackgroundImage"];
CIImage *outputImage = [compositingFilter valueForKey:@"outputImage"];
[outputImage drawAtPoint:NSZeroPoint
fromRect:bounds
operation:NSCompositeCopy
fraction:1.0];
[tintedImage unlockFocus];
return [tintedImage autorelease];
}
else {
return [[self copy] autorelease];
}
}
- (NSImage*)imageCroppedToRect:(NSRect)rect
{
NSPoint point = { -rect.origin.x, -rect.origin.y };
NSImage *croppedImage = [[NSImage alloc] initWithSize:rect.size];
[croppedImage lockFocus];
{
[self compositeToPoint:point operation:NSCompositeCopy];
}
[croppedImage unlockFocus];
return [croppedImage autorelease];
}
CIMultiplyCompositing滤镜或者替换为另一个滤镜... - glasz
extension NSImage {
func tinting(with tintColor: NSColor) -> NSImage {
guard let cgImage = self.cgImage(forProposedRect: nil, context: nil, hints: nil) else { return self }
return NSImage(size: size, flipped: false) { bounds in
guard let context = NSGraphicsContext.current?.cgContext else { return false }
tintColor.set()
context.clip(to: bounds, mask: cgImage)
context.fill(bounds)
return true
}
}
}
以扩展的形式编写的 Swift 版本:
extension NSImage {
func tintedImageWithColor(color:NSColor) -> NSImage {
let size = self.size
let imageBounds = NSMakeRect(0, 0, size.width, size.height)
let copiedImage = self.copy() as! NSImage
copiedImage.lockFocus()
color.set()
NSRectFillUsingOperation(imageBounds, .CompositeSourceIn)
copiedImage.unlockFocus()
return copiedImage
}
}
func tinted(color: NSColor) -> NSImage。 - JuullockFocus方法在macOS 13.0版本之后已被弃用。 - HangarRash//assume inputImage is the greyscale CIImage you want to tint
CIImage* outputImage = nil;
//create some green
CIFilter* greenGenerator = [CIFilter filterWithName:@"CIConstantColorGenerator"];
CIColor* green = [CIColor colorWithRed:0.30 green:0.596 blue:0.172];
[greenGenerator setValue:green forKey:@"inputColor"];
CIImage* greenImage = [greenGenerator valueForKey:@"outputImage"];
//apply a multiply filter
CIFilter* filter = [CIFilter filterWithName:@"CIMultiplyCompositing"];
[filter setValue:greenImage forKey:@"inputImage"];
[filter setValue:inputImage forKey:@"inputBackgroundImage"];
outputImage = [filter valueForKey:@"outputImage"];
[outputImage drawAtPoint:NSZeroPoint fromRect:NSRectFromCGRect([outputImage extent]) operation:NSCompositeCopy fraction:1.0];
CIImage的示例，实际上并不需要获取图像本身。正如您所指出的那样，您已经从前一行代码中获得了实际图像。 - Rob KenigerSwift 5 版本还可以处理色调颜色的 alpha 分量。
我使用这个功能来支持多种图标状态的黑暗模式，通过将模板图标转换为不同的颜色和透明度级别。例如，您可以传递 NSColor(white: 0, alpha: 0.5) 来获取一个在浅色模式下变暗的图标版本，以及 NSColor(white: 1, alpha: 0.5) 来获取一个在深色模式下变暗的图标版本。
func tintedImage(_ image: NSImage, color: NSColor) -> NSImage {
let newImage = NSImage(size: image.size)
newImage.lockFocus()
// Draw with specified transparency
let imageRect = NSRect(origin: .zero, size: image.size)
image.draw(in: imageRect, from: imageRect, operation: .sourceOver, fraction: color.alphaComponent)
// Tint with color
color.withAlphaComponent(1).set()
imageRect.fill(using: .sourceAtop)
newImage.unlockFocus()
return newImage
}
- (void)lockFocus; 重写为 imageWithSize:flipped:drawingHandler:。@interface NSImage(Additions)
- (NSImage *)imageTintedWithColor:(NSColor *)tint;
@end
@implementation NSImage(Additions)
- (NSImage *)imageTintedWithColor:(NSColor *)tint
{
NSImage *copy = [self copy]; // we need to break block retain cycle
NSImage *image = [NSImage imageWithSize:copy.size flipped:NO drawingHandler:^BOOL(NSRect dstRect) {
[tint set];
NSRect imageRect = {NSZeroPoint, [copy size]};
[copy drawInRect:imageRect];
NSRectFillUsingOperation(imageRect, NSCompositingOperationSourceIn);
return YES;
}];
return image;
}
lockFocus已被弃用。
我使用符号配置使其正常工作。let config = NSImage.SymbolConfiguration(paletteColors: [.systemTeal, .systemGray])
let nuImage = image.withSymbolConfiguration(config)