iphone - 从原始 RGBA 数据创建 UIImage

Question

我一直在尝试将数组 RGBA 数据(int 字节)转换为 UIImage。我的代码如下所示:

/*height and width are integers denoting the dimensions of the image*/
unsigned char *rawData = malloc(width*height*4);

for (int i=0; i<width*height; ++i) 
{
    rawData[4*i] = <red_val>;
    rawData[4*i+1] = <green_val>;
    rawData[4*i+2] = <blue_val>;
    rawData[4*i+3] = 255;
}


/*I Have the correct values displayed
    - ensuring the rawData is well populated*/

NSLog(@"(%i,%i,%i,%f)",rawData[0],rawData[1],rawData[2],rawData[3]/255.0f);
NSLog(@"(%i,%i,%i,%f)",rawData[4],rawData[5],rawData[6],rawData[7]/255.0f);
NSLog(@"(%i,%i,%i,%f)",rawData[8],rawData[9],rawData[10],rawData[11]/255.0f);



CGDataProviderRef provider = CGDataProviderCreateWithData(NULL, 
                                                          rawData, 
                                                          width*height*4, 
                                                          NULL);

int bitsPerComponent = 8;
int bitsPerPixel = 32;
int bytesPerRow = 4*width;
CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB();
CGBitmapInfo bitmapInfo = kCGBitmapByteOrderDefault;
CGColorRenderingIntent renderingIntent = kCGRenderingIntentDefault;
CGImageRef imageRef = CGImageCreate(width,
                                    height,
                                    8,
                                    32,
                                    4*width,colorSpaceRef,
                                    bitmapInfo,
                                    provider,NULL,NO,renderingIntent);
/*I get the current dimensions displayed here */
NSLog(@"width=%i, height: %i", CGImageGetWidth(imageRef),
      CGImageGetHeight(imageRef) );
UIImage *newImage = [UIImage imageWithCGImage:imageRef];
/*This is where the problem lies. 
  The width, height displayed are of completely different dimensions
  viz. the width is always zero and the height is a very huge number */

NSLog(@"resultImg width:%i, height:%i",
          newImage.size.width,newImage.size.height);


return newImage;

我收到的输出图像是宽度为 0、高度为 1080950784 的图像(假设我的初始高度和宽度分别为 240 和 240)。我一直在努力解决这个问题，并检查了许多相关论坛，例如(link text)关于如何去做但收效甚微。

Answer 1

事实证明，这个问题是一个非常愚蠢的错误，我们都忽略了。 UIImage 尺寸存储为 float ，而不是整数。 :D

尝试

NSLog(@"resultImg width:%f, height:%f",
          newImage.size.width,newImage.size.height);

相反。图像尺寸已正确传输。