从iPhone中的颜色阵列创建图像

问题描述：

我有一个颜色作为其对象的数组。我想从中创建一个图像。实际上，发生的事情是，我正在获取图像中每个像素的像素值，修改它并将其对象存储在可变数组中。现在想从中画出一张图片。怎么做？？任何想法？？？从iPhone中的颜色阵列创建图像

-(UIImage*)modifyPixels:(UIImage*)originalImage { 
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc]init]; 
    NSMutableArray *result =[[NSMutableArray alloc]init]; 
    int width = img.size.width; 
    int height = img.size.height; 
     originalImage = imageView.image; 

    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); 

    unsigned char *rawData = malloc (height * width * 4); 
    NSUInteger bytesPerPixel = 4; 
    NSUInteger bytesPerRow = bytesPerPixel * width; 
    NSUInteger bitsPerComponent = 8; 
    CGContextRef context = CGBitmapContextCreate(rawData, width, height, bitsPerComponent, bytesPerRow, colorSpace, kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big); 
    CGColorSpaceRelease(colorSpace); 

    CGContextDrawImage(context, CGRectMake(0, 0, width, height),img.CGImage); 
    CGContextRelease(context); 
    int byteIndex = 0; 
    for (int xx=0;xx<width;xx++){ 
     for (int yy=0;yy<height;yy++){ 
    // Now rawData contains the image data in the RGBA8888 pixel format. 
      NSLog(@"(%d,%d)",xx,yy); 
    NSLog(@"Alpha 255-Value is: %u", rawData[byteIndex + 3]); 
    NSLog(@"Red 255-Value is: %u", rawData[byteIndex]); 
    NSLog(@"Green 255-Value is: %u",rawData[byteIndex + 1]); 
    NSLog(@"Blue 255-Value is: %u",rawData[byteIndex + 2]); 
      CGFloat red = (rawData[byteIndex]+rawData[byteIndex + 1]+rawData[byteIndex + 2])/3; 
      CGFloat green = red; 
      CGFloat blue = red; 
      CGFloat alpha = 255; 
      byteIndex += 4; 

      UIColor *acolor = [UIColor colorWithRed:red green:green blue:blue alpha:alpha]; 
      [result addObject:acolor]; 
       } 

     } 
     UIImage *newImage; 
     //CREATE NEW UIIMAGE (newImage) HERE from acolor(array of colors) 
//this is the portion i'm in trouble with 

     return newImage;  
     [pool release]; 
    }

[池版本]是无法访问的代码，并导致泄漏。无论如何，该方法不应该需要自己的池。您也可以在Xcode项目中启用Clang静态分析工具。（在组树中的'获取信息'在你的项目中 - >'运行静态分析器'） – 2009-12-21 09:45:22

答

据我了解，你尝试平均所有渠道。
你可以试试下面的方法，它使用核芯显卡：

CGImageRef inImage = mainImageView.image.CGImage;   
CFDataRef dataRef = CGDataProviderCopyData(CGImageGetDataProvider(inImage)); 
UInt8* pixelBuffer = (UInt8*)CFDataGetBytePtr(dataRef); 
int length = CFDataGetLength(dataRef); 
for (int index = 0; index < length; index += 4) 
{ 
    pixelBuffer[index + 1] = (pixelBuffer[index + 1] + pixelBuffer[index + 2] + pixelBuffer[index + 3])/3.0; 
    pixelBuffer[index + 2] = pixelBuffer[index + 1]; 
    pixelBuffer[index + 3] = pixelBuffer[index + 1];  
} 
CGContextRef ctx = CGBitmapContextCreate(pixelBuffer, 
             CGImageGetWidth(inImage), 
             CGImageGetHeight(inImage), 
             8, 
             CGImageGetBytesPerRow(inImage), 
             CGImageGetColorSpace(inImage), 
             kCGImageAlphaPremultipliedFirst); 
CGImageRef imageRef = CGBitmapContextCreateImage(ctx); 
UIImage* rawImage = [UIImage imageWithCGImage:imageRef]; 
CGContextRelease(ctx); 
CFRelease(dataRef); 
CGImageRelease(imageRef);

结果存储在rawImage。您可以查看GLImageProcessing sample from Apple。
这显示了使用OpenGL的iPhone上的一些基本图像处理技术。

从iPhone中的颜色阵列创建图像

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