GD PHP旋转图像黑色边框

Question

I try to resize and rotate an image with PHP (GD) but when image rotate, it add a black border on right.

Exemple image (before resize & rotate):

Exemple image (after resize & rotate):

Here is my code :

    $image = $_FILES["file"]["name"];
    $uploadedfile = $_FILES['file']['tmp_name'];

    if ($image) {

        $filename = stripslashes($_FILES['file']['name']);

        $i = strrpos($filename,".");
        $l = strlen($filename) - $i;
        $ext = substr($filename,$i+1,$l);

        $extension = strtolower($ext);

        if (($extension != "jpg") && ($extension != "jpeg") 
            && ($extension != "png") && ($extension != "gif")) {

            echo ' Unknown Image extension ';
            $errors=1;
        }

        else {
            $size=filesize($_FILES['file']['tmp_name']);

            if($extension=="jpg" || $extension=="jpeg" ) {
                $uploadedfile = $_FILES['file']['tmp_name'];
                $src = imagecreatefromjpeg($uploadedfile);
            }
            else if($extension=="png") {
                $uploadedfile = $_FILES['file']['tmp_name'];
                $src = imagecreatefrompng($uploadedfile);
            }
            else  {
                $src = imagecreatefromgif($uploadedfile);
            }

            $max_width = 175;
            $max_height = 100;

            $size=GetImageSize($uploadedfile);

            $width_ratio = ($size[0] / $max_width);
            $height_ratio = ($size[1] / $max_height);

            if($width_ratio >=$height_ratio) 
            {
                $ratio = $width_ratio;
            }
            else
            {
                $ratio = $height_ratio;
            }

            $new_width = ($size[0] / $ratio);
            $new_height = ($size[1] / $ratio);
            $tmp=imagecreatetruecolor($new_width,$new_height);

            if(function_exists("exif_read_data")){
                $exif = @exif_read_data($uploadedfile);

                $rotateImg = imagerotate($src,0,0);

                if(!empty($exif['Orientation'])) {
                    switch($exif['Orientation']) {
                    case 8:
                        $rotateImg = imagerotate($src,90,0);
                        break;
                    case 3:
                        $rotateImg = imagerotate($src,180,0);
                        break;
                    case 6:
                        $rotateImg = imagerotate($src,-90,0);
                        break;
                    } 
                }
            }

            imagecopyresampled($tmp,$rotateImg,0,0,0,0,($new_width-1),($new_height-1),$size[0],$size[1]);

            $filename = sha1(basename( $_FILES['file']['name']));
            $path = dirname(__FILE__)."/../files/pictures/".$filename;

            imagejpeg($tmp,$path,100);

            imagedestroy($src);
            imagedestroy($rotateImg);
            imagedestroy($tmp);


        }
    }

I tried some modification like the answers of this posts : - A border appears when rotating image with gd + php - PHP - Rotate image with GD gives black borders - Why when i rotate the image black borders appear? PHP GD

But nothing work.

Please guys helps me.

Thanks you

Answer 1

The problem occurs if the EXIF data indicates rotation is necessary, because after the rotation the values of height and width are still treated the same. Since the image has been rotated these values should be switched with one another.

The rotation needs to be done first, not last, so move the rotation code above all of the ratio calculations (to just after you declare $size). You'll need to keep track of a 90/-90 degree rotation taking place:

$rotated = false;
if (!empty($exif['Orientation'])) {
    switch ($exif['Orientation']) {
        case 8:
            $src = imagerotate($src, 90, 0);
            $rotated = true;
            break;
        case 3:
            $src = imagerotate($src, 180, 0);
            break;
        case 6:
            $src = imagerotate($src, -90, 0);
            $rotated = true;
            break;
    }
}

Now you need to 'flip' the values if the orientation has changed:

if ($rotated) {
    $width = $size[1];
    $height = $size[0];
} else {
    $width = $size[0];
    $height = $size[1];
}

In the rest of your code replace instances of $size[0] with $width and $size[1] with $height to fix the calculations.

You could also ...($new_width-1),($new_height-1)... to just ...$new_width, $new_height... to make the resized image fit correctly, otherwise there is a 1px black border on the right and bottom of the resulting image.