What potential pitfalls should be considered when using md5 to compare images in PHP?

When using md5 to compare images in PHP, one potential pitfall to consider is that md5 hashes are not always unique for different images, which can lead to false positives in image comparison. To address this issue, you can combine md5 hashing with additional techniques such as comparing image dimensions or using more advanced hashing algorithms like sha1 or sha256 for better accuracy.

function compareImages($image1, $image2) {
    $hash1 = md5_file($image1);
    $hash2 = md5_file($image2);

    // Additional checks such as comparing image dimensions
    $dimensions1 = getimagesize($image1);
    $dimensions2 = getimagesize($image2);

    if ($hash1 == $hash2 && $dimensions1 == $dimensions2) {
        return true;
    } else {
        return false;
    }
}