大家好，我是ios开发的一个小白，问一下关于IOS相册选取图片后图片模糊的原因。

Question

#pragma mark - CGImagePickController NotificationCenter

• (void) CTAssetsPickCGImage:(NSNotification *)notice
  {
  NSArray *assetArr = [notice object];
  for (int x = 0; x < assetArr.count; x ++) {
  if (frameX <6) {
  ALAsset * asset = [assetArr objectAtIndex:x];
  scaleImage = [UIImage imageWithCGImage:asset.thumbnail];

      CTAssetsImage = [[UIImageView alloc] initWithFrame:[self isIndex]];
      CTAssetsImage.image = scaleImage;
      CTAssetsImage.tag = 999 + frameX;
      [postView addSubview:CTAssetsImage];
  
      UIButton * CTAssetButton = [[UIButton alloc] initWithFrame:CTAssetsImage.frame];
      [CTAssetButton addTarget:self action:@selector(CTAssetsAction:) forControlEvents:UIControlEventTouchUpInside];
      CTAssetButton.tag = 999 + frameX;
      [postView addSubview:CTAssetButton];
  
      [[NSNotificationCenter defaultCenter] removeObserver:self name:@"CGImageCTAssetsPickController" object:nil];
  }
  else
  {
      [SVProgressHUD showErrorWithStatus:@"最多只能选择6张图片"];
  }
  

  }
  }

asset.thumbnail是一个CGImageRef的图片，我设置了一个UIImageView 大小是80*80，用于显示这张CGImageRef。然后我想点击到这张图片的时候，可以放大这张图片，还原回图片原先的样子，但是我发现图片变得模糊。google了很久也没找到原因，想询问一下各位高手。

Answer 1

取CGImage的图片是否会自动变得模糊？我打印了一下assets.thumbnail的height width的值。但是发现不管怎样都只有157？