图片解压缩

• (UIImage *)decompressedImageWithData:(NSData *)data
  {
  CGImageSourceRef source = CGImageSourceCreateWithData((__bridge CFDataRef)data, NULL);
  CGImageRef cgImage = CGImageSourceCreateImageAtIndex(source, 0, (__bridge CFDictionaryRef)@{(id)kCGImageSourceShouldCacheImmediately: @YES});

  UIImage *image = [UIImage imageWithCGImage:cgImage];
  CGImageRelease(cgImage);
  CFRelease(source);
  return image;
  }