/**
* 偽隨機(jī)數(shù)
*/
static NSInteger ATNoiseRseed = 115;
static inline NSInteger ATNoiseRand() {
return (ATNoiseRseed = (ATNoiseRseed * 214013 + 2531011) & ((1U << 31) - 1)) >> 16;
}
/**
* 圖片加入雜色, intensity: 0.0 ~ 1.0f, gary: YES標(biāo)示單色噪點(diǎn)
*/
- (UIImage *)imageWithNoiseIntensity:(CGFloat)intensity gray:(BOOL)isGray
{
UIImage *image;
int width = self.size.width * self.scale;
int height = self.size.height * self.scale;
CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceRGB();
if (colorspace == NULL) {
ATLog(@"Create Colorspace Error!");
return nil;
}
Byte *imgData = NULL;
imgData = malloc(width * height * 4);
if (imgData == NULL) {
ATLog(@"Memory Error!");
CGColorSpaceRelease(colorspace);
return nil;
}
CGContextRef bmpContext = CGBitmapContextCreate(imgData, width, height, 8, width * 4, colorspace, (CGBitmapInfo)kCGImageAlphaPremultipliedLast);
if (!bmpContext) {
ATLog(@"Create Bitmap context Error!");
CGColorSpaceRelease(colorspace);
return nil;
}
CGContextDrawImage(bmpContext, CGRectMake(0, 0, width, height), self.CGImage);
for (long i = 0; i < width * height; i++) {
int randR = (ATNoiseRand()%511-255) * intensity;
int randG = isGray ? randR : (ATNoiseRand()%511-255) * intensity;
int randB = isGray ? randR : (ATNoiseRand()%511-255) * intensity;
imgData[4*i+0] = MAX(0, MIN(255, (imgData[4*i+0] + randR)));
imgData[4*i+1] = MAX(0, MIN(255, (imgData[4*i+1] + randG)));
imgData[4*i+2] = MAX(0, MIN(255, (imgData[4*i+2] + randB)));
imgData[4*i+3] = 255;
}
CGImageRef imageRef = CGBitmapContextCreateImage(bmpContext);
if (imageRef != NULL) {
image = [[UIImage alloc] initWithCGImage:imageRef];
CGImageRelease(imageRef);
}
CGColorSpaceRelease(colorspace);
CGContextRelease(bmpContext);
free(imgData);
return image;
}
為UIImage添加分類深纲，圖片加入雜色, intensity: 0.0 ~ 1.0f, gary: YES標(biāo)示單色噪點(diǎn)鳖孤。
