UIImagePickerController拍照上传图片旋转问题

来源：互联网发布：流光软件编辑：程序博客网时间：2024/04/30 11:31

转载地址：http://www.cnblogs.com/yajunLi/p/5796084.html

问题描述：

手机头像上传，遇到一个怪现象，就是拍照上传时，手机端显示头像正常，但在web端查看会有一个左旋90度的问题。

并且照片竖怕才会有此问题，横拍不存在。

原因分析：

手机拍照时，用相机拍摄出来的照片是含有EXIF信息的，在我们得到 UIImage时，可以查看此Image的imageOrientation属性，其实就是指的EXIF中的orientation信息。

如果我们忽略orientation信息，而直接对照片进行像素处理或上传等操作，得到的结果是翻转或者旋转90之后的样子。

这是因为我们执行像素处理或者drawInRect等操作之后，imageOrientaion信息被删除了，imageOrientaion被重设为0，造成照片内容和imageOrientaion不匹配。

所以，在对照片进行处理之前，先将照片旋转到正确的方向，保证返回的imageOrientaion为0。

解决方法：

Swift版：

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
/**
     照片竖拍  web显示旋转解决:图片大于2M会自动旋转90度
      
     - parameter aImage: <#aImage description#>
      
     - returns: <#return value description#>
     */
    class func fixOrientation(aImage:UIImage)->UIImage  {
        if aImage.imageOrientation == UIImageOrientation.Up{
            return aImage
        }
     
        var transform = CGAffineTransformIdentity
         
        switch (aImage.imageOrientation) {
        case .Down,.DownMirrored:
        transform = CGAffineTransformTranslate(transform, aImage.size.width, aImage.size.height)
        transform = CGAffineTransformRotate(transform, CGFloat(M_PI))
        break;
         
        case .Left,.LeftMirrored:
        transform = CGAffineTransformTranslate(transform, aImage.size.width, 0)
        transform = CGAffineTransformRotate(transform, CGFloat(M_PI_2))
        break;
         
        case .Right,.RightMirrored:
        transform = CGAffineTransformTranslate(transform, 0, aImage.size.height)
        transform = CGAffineTransformRotate(transform, CGFloat(-M_PI_2))
        break;
        default:
        break;
        }
         
        switch (aImage.imageOrientation) {
        case .UpMirrored,.DownMirrored:
        transform = CGAffineTransformTranslate(transform, aImage.size.width, 0)
        transform = CGAffineTransformScale(transform, -1, 1)
        break;
         
        case .LeftMirrored,.RightMirrored:
        transform = CGAffineTransformTranslate(transform, aImage.size.height, 0)
        transform = CGAffineTransformScale(transform, -1, 1)
        break;
        default:
        break;
        }
         
        let ctx:CGContextRef = CGBitmapContextCreate(nil, Int(aImage.size.width), Int(aImage.size.height),
        CGImageGetBitsPerComponent(aImage.CGImage), 0,
        CGImageGetColorSpace(aImage.CGImage),
        1)!
 
 
         
        CGContextConcatCTM(ctx, transform)
        switch (aImage.imageOrientation) {
        case .Left,.LeftMirrored,.Right,.RightMirrored:
        CGContextDrawImage(ctx, CGRectMake(0,0,aImage.size.height,aImage.size.width), aImage.CGImage)
        break;
         
        default:
        CGContextDrawImage(ctx, CGRectMake(0,0,aImage.size.width,aImage.size.height), aImage.CGImage);
        break;
        }
         
        let cgimg:CGImageRef = CGBitmapContextCreateImage(ctx)!
        let img:UIImage = UIImage(CGImage: cgimg)
        return img;
        }

OC版：

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
- (UIImage *)fixOrientation:(UIImage *)aImage { 
     
  // No-op if the orientation is already correct 
  if (aImage.imageOrientation == UIImageOrientationUp)  
    return aImage; 
     
  // We need to calculate the proper transformation to make the image upright. 
  // We do it in 2 steps: Rotate if Left/Right/Down, and then flip if Mirrored. 
  CGAffineTransform transform = CGAffineTransformIdentity; 
     
  switch (aImage.imageOrientation) { 
    case UIImageOrientationDown: 
    case UIImageOrientationDownMirrored: 
      transform = CGAffineTransformTranslate(transform, aImage.size.width, aImage.size.height); 
      transform = CGAffineTransformRotate(transform, M_PI); 
      break; 
         
    case UIImageOrientationLeft: 
    case UIImageOrientationLeftMirrored: 
      transform = CGAffineTransformTranslate(transform, aImage.size.width, 0); 
      transform = CGAffineTransformRotate(transform, M_PI_2); 
      break; 
         
    case UIImageOrientationRight: 
    case UIImageOrientationRightMirrored: 
      transform = CGAffineTransformTranslate(transform, 0, aImage.size.height); 
      transform = CGAffineTransformRotate(transform, -M_PI_2); 
      break; 
    default: 
      break; 
  } 
     
  switch (aImage.imageOrientation) { 
    case UIImageOrientationUpMirrored: 
    case UIImageOrientationDownMirrored: 
      transform = CGAffineTransformTranslate(transform, aImage.size.width, 0); 
      transform = CGAffineTransformScale(transform, -1, 1); 
      break; 
         
    case UIImageOrientationLeftMirrored: 
    case UIImageOrientationRightMirrored: 
      transform = CGAffineTransformTranslate(transform, aImage.size.height, 0); 
      transform = CGAffineTransformScale(transform, -1, 1); 
      break; 
    default: 
      break; 
  } 
     
  // Now we draw the underlying CGImage into a new context, applying the transform 
  // calculated above. 
  CGContextRef ctx = CGBitmapContextCreate(NULL, aImage.size.width, aImage.size.height, 
                       CGImageGetBitsPerComponent(aImage.CGImage), 0, 
                       CGImageGetColorSpace(aImage.CGImage), 
                       CGImageGetBitmapInfo(aImage.CGImage)); 
  CGContextConcatCTM(ctx, transform); 
  switch (aImage.imageOrientation) { 
    case UIImageOrientationLeft: 
    case UIImageOrientationLeftMirrored: 
    case UIImageOrientationRight: 
    case UIImageOrientationRightMirrored: 
      // Grr... 
      CGContextDrawImage(ctx, CGRectMake(0,0,aImage.size.height,aImage.size.width), aImage.CGImage); 
      break; 
         
    default: 
      CGContextDrawImage(ctx, CGRectMake(0,0,aImage.size.width,aImage.size.height), aImage.CGImage); 
      break; 
  } 
     
  // And now we just create a new UIImage from the drawing context 
  CGImageRef cgimg = CGBitmapContextCreateImage(ctx); 
  UIImage *img = [UIImage imageWithCGImage:cgimg]; 
  CGContextRelease(ctx); 
  CGImageRelease(cgimg); 
  return img; 
}

亲测，在完成拍照代理里，获取到图片后，用此方法处理后，再上传服务器，可解决该问题。

1
2
3
4
5
6
7
8
9
10
11
12
//若是图片
var img:UIImage = info[UIImagePickerControllerOriginalImage] as! UIImage
//保存相册
UIImageWriteToSavedPhotosAlbum(img, self, nil, nil)
 
img = PublicMethod.fixOrientation(img)
 
//压缩图片
let imgData:NSData = UIImageJPEGRepresentation(img, 0.2)!
//上传服务器
self.uploadHeadImg(imgData, headImage: img)

参考文献：http://blog.csdn.net/hitwhylz/article/details/39518463

0 0