如何将NSImage转换为NSBitmapImageRep?下面是我的代码:
- (NSBitmapImageRep *)bitmapImageRepresentation
{
NSBitmapImageRep *ret = (NSBitmapImageRep *)[self representations];
if(![ret isKindOfClass:[NSBitmapImageRep class]])
{
ret = nil;
for(NSBitmapImageRep *rep in [self representations])
if([rep isKindOfClass:[NSBitmapImageRep class]])
{
ret = rep;
break;
}
}
if(ret == nil)
{
NSSize size = [self size];
size_t width = size.width;
size_t height = size.height;
size_t bitsPerComp = 32;
size_t bytesPerPixel = (bitsPerComp / CHAR_BIT) * 4;
size_t bytesPerRow = bytesPerPixel * width;
size_t totalBytes = height * bytesPerRow;
NSMutableData *data = [NSMutableData dataWithBytesNoCopy:calloc(totalBytes, 1) length:totalBytes freeWhenDone:YES];
CGColorSpaceRef space = CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB);
CGContextRef ctx = CGBitmapContextCreate([data mutableBytes], width, height, bitsPerComp, bytesPerRow, CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB), kCGBitmapFloatComponents | kCGImageAlphaPremultipliedLast);
if(ctx != NULL)
{
[NSGraphicsContext saveGraphicsState];
[NSGraphicsContext setCurrentContext:[NSGraphicsContext graphicsContextWithGraphicsPort:ctx flipped:[self isFlipped]]];
[self drawAtPoint:NSZeroPoint fromRect:NSZeroRect operation:NSCompositeCopy fraction:1.0];
[NSGraphicsContext restoreGraphicsState];
CGImageRef img = CGBitmapContextCreateImage(ctx);
ret = [[NSBitmapImageRep alloc] initWithCGImage:img];
[self addRepresentation:ret];
CFRelease(img);
CFRelease(space);
CGContextRelease(ctx);
}
}
return ret;
}
它有效,但会导致内存泄漏,至少我在使用ARC时是这样。使用
initWithData:[nsimagename TIFFRepresentation]
不正确工作。某些图像的表示不好。我认为这取决于图像的格式和颜色空间。是否有其他方法可以实现这一点?
mrwalker建议的结果:
原始图像:
![enter image description here](https://istack.dev59.com/q8thT.webp)
![enter image description here](https://istack.dev59.com/5JT5l.webp)
![enter image description here](https://istack.dev59.com/VnMOc.webp)