上传PHP后修复iOS图片方向

Question

如果图片在从上传后没有正确定位，那么是否有一种方法可以只使用旋转图片？

有些图片是旋转90度，而另一些正确上传。

Answer 1

图像是旋转的，因为您保存的图像在JPEG，如果您保存您的图像在PNG，那么方向将不会改变。下面是修复定向问题的代码。

- (UIImage *)fixrotation:(UIImage *)image{   

    if (image.imageOrientation == UIImageOrientationUp) return image;
    CGAffineTransform transform = CGAffineTransformIdentity;

    switch (image.imageOrientation) {
        case UIImageOrientationDown:
        case UIImageOrientationDownMirrored:
            transform = CGAffineTransformTranslate(transform, image.size.width, image.size.height);
            transform = CGAffineTransformRotate(transform, M_PI);
            break;

        case UIImageOrientationLeft:
        case UIImageOrientationLeftMirrored:
            transform = CGAffineTransformTranslate(transform, image.size.width, 0);
            transform = CGAffineTransformRotate(transform, M_PI_2);
            break;

        case UIImageOrientationRight:
        case UIImageOrientationRightMirrored:
            transform = CGAffineTransformTranslate(transform, 0, image.size.height);
            transform = CGAffineTransformRotate(transform, -M_PI_2);
            break;
        case UIImageOrientationUp:
        case UIImageOrientationUpMirrored:
            break;
    }

    switch (image.imageOrientation) {
        case UIImageOrientationUpMirrored:
        case UIImageOrientationDownMirrored:
            transform = CGAffineTransformTranslate(transform, image.size.width, 0);
            transform = CGAffineTransformScale(transform, -1, 1);
            break;

        case UIImageOrientationLeftMirrored:
        case UIImageOrientationRightMirrored:
            transform = CGAffineTransformTranslate(transform, image.size.height, 0);
            transform = CGAffineTransformScale(transform, -1, 1);
            break;
        case UIImageOrientationUp:
        case UIImageOrientationDown:
        case UIImageOrientationLeft:
        case UIImageOrientationRight:
            break;
    }

    // Now we draw the underlying CGImage into a new context, applying the transform
    // calculated above.
    CGContextRef ctx = CGBitmapContextCreate(NULL, image.size.width, image.size.height,
                                             CGImageGetBitsPerComponent(image.CGImage), 0,
                                             CGImageGetColorSpace(image.CGImage),
                                             CGImageGetBitmapInfo(image.CGImage));
    CGContextConcatCTM(ctx, transform);
    switch (image.imageOrientation) {
        case UIImageOrientationLeft:
        case UIImageOrientationLeftMirrored:
        case UIImageOrientationRight:
        case UIImageOrientationRightMirrored:
            // Grr...
            CGContextDrawImage(ctx, CGRectMake(0,0,image.size.height,image.size.width), image.CGImage);
            break;

        default:
            CGContextDrawImage(ctx, CGRectMake(0,0,image.size.width,image.size.height), image.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;
}

Answer 2

使用数据查找图像的方向：

$exif = exif_read_data('image.jpg');

if (isset($exif['Orientation']))
{
  switch ($exif['Orientation'])
  {
    case 3:
      // Need to rotate 180 deg
      break;

    case 6:
      // Need to rotate 90 deg clockwise
      break;

    case 8:
      // Need to rotate 90 deg counter clockwise
      break;
  }
}

您可以在这里找到一个关于定位代码的解释：http://www.impulseadventure.com/photo/exif-orientation.html

Answer 3

我已经创建了一个功能，以纠正存档的图像，你可以使用这个小修改，以进行空中校正。

函数的要点链接

<?php
/*
Correct image orientation v1.0

Author: Mathuvathanan Mounasamy

Licensed under the MIT license

This function correct all the images' orientation in a given path or directory.

Run:    php -r "require 'correctImageOrientation.php'; correctImageOrientation('test/');"
        or
        php -r "require 'correctImageOrientation.php'; correctImageOrientation('test/test1');"
        or
        php -r "require 'correctImageOrientation.php'; correctImageOrientation('test');"
*/
function correctImageOrientation($directory) {
    $scanned_directory = array_diff(scandir($directory), array('..', '.'));
    echo "<pre>";
    print_r("scanned directory: \r\n");
    print_r($scanned_directory);
    echo "</pre>\r\n";
    foreach ($scanned_directory as &$file) {

        if (is_dir($directory."/".$file)) {
            correctImageOrientation($directory."/".$file);
        } else {                                    
            $filen = explode(".", $file);
            $ext = end($filen);
            try {

                $exif = @exif_read_data($directory."/".$file);

                $orientation = $exif['Orientation'];

                if (isset($orientation) && $orientation != 1){
                    switch ($orientation) {
                        case 3:
                        $deg = 180;
                        break;
                        case 6:
                        $deg = 270;
                        break;
                        case 8:
                        $deg = 90;
                        break;
                    }

                    if ($deg) {

                        // If png
                        if ($ext == "png") {
                            $img_new = imagecreatefrompng($directory."/".$file);
                            $img_new = imagerotate($img_new, $deg, 0);

                            // Save rotated image
                            imagepng($img_new,$directory.$file);
                        }else {
                            $img_new = imagecreatefromjpeg($directory."/".$file);
                            $img_new = imagerotate($img_new, $deg, 0);

                            // Save rotated image
                            imagejpeg($img_new,$directory."/".$file,80);
                        }
                    }
                    echo "<pre>";
                    print_r("image changed: \r\n");
                    print_r($directory."/".$file);
                    echo "</pre>\r\n";
                }

            } catch (Exception $e) {
                echo "error:";
                echo $e;
                echo "error";
            }
        }
    }
    unset($file);
}

?>