Why are iPhone and Android image orientations not being corrected using PHP\'s `exif_read_data` function?

PHP read_exif_data and Adjust Orientation

The provided code attempts to adjust the orientation of uploaded JPEG images based on the EXIF data. However, users have reported issues with images from iPhones and Android devices.

Code Analysis

The EXIF data is extracted using the exif_read_data function. The switch statement checks for specific orientations and attempts to rotate the image accordingly. However, it appears that the provided EXIF data does not contain a valid Orientation value.

Updated Code

To fix this issue, we can use a more robust method to extract orientation data. Here's an updated version of the code:

<code class="php">$exif = exif_read_data($upload_path . $newfilename, 'ANY_TAG');
$ort = $exif['IFD0']['Orientation'] ?? 1;</code>

EXIF Orientation Values

The Orientation value can range from 1 to 8, with different values indicating different rotations or flipping.

• 1: Horizontal (normal)
• 3: 180° CW rotation
• 6: 90° CW rotation
• 8: 90° CCW rotation
• 2: Horizontal flip
• 4: Vertical flip
• 5: Horizontal flip and 90° CW rotation
• 7: Vertical flip and 90° CW rotation

Adjusting Image Orientation

With the correct orientation value, we can then adjust the image as needed:

<code class="php">switch ($ort)
{
    case 3: // 180 rotate left
        $image->imagerotate(-180, -1);
        break;

    case 6: // 90 rotate right
        $image->imagerotate(-90, -1);
        break;

    case 8:    // 90 rotate left
        $image->imagerotate(90, -1);
        break;
}</code>

Additional Considerations

If the EXIF data still doesn't contain the Orientation value or the adjustment doesn't seem to work, you may need to consult specific documentation for your image library or consider using alternative methods to determine the correct orientation.

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