How do i get a transparent background after rotaing a png image with php?

Question

So I have png image and I rotate it but i get a black background.. or if i do the color code ofr white i get white.. I tried doing this..

$trans = imagecol         


        

Answer 1

Have you tried this?

imagecolortransparent

Hope i understood your question!

Answer 2

This is what I am using, this work great for .png files with transparent backgrounds. High fives!

function rotate($degrees) {

    // Switch from default counter-clockwise to clockwise
    $degrees = 360 - $degrees; 

    // Get the image 
    $source =  imagecreatefrompng("images/image.png");

    // Rotate the image
    $rotated_image = imagerotate($source, $degrees, imageColorAllocateAlpha($source, 0, 0, 0, 127));

    // Save the rotated image
    imagepng($rotated_image, 'images/rotated_image.png');

}

Answer 3

You can try this: http://www.exorithm.com/algorithm/view/rotate_image_alpha

Answer 4

    $info = pathinfo($pathToImage);
    $name = str_replace("." . $info['extension'], "", $info['basename']);

    $size = getimagesize($pathToImage);



    $type = isset($size['type']) ? $size['type'] : $size[2];

    // Check support of file type
    if (!(imagetypes() & $type)) {
        // Server does not support file type
        return false;
    }

    $source = self::imageCreateFrom($pathToImage, trim($info['extension'])) or notfound();
    $transColor = imagecolorallocatealpha($source, 255, 255, 255, 127);

    // $transparency = imagecolorallocatealpha($source, 0, 0, 0, 127);
    $rotate = imagerotate($source, 360 - $rotate_angle, $transColor);
    //imagealphablending($rotate, false);


    imagesavealpha($rotate, TRUE);
    //imagejpeg($rotate,$pathToThumbs.DIRECTORY_SEPARATOR.$info['basename']);
    self::createImage($rotate, $pathToThumbs, $info['basename'], trim($info['extension']));

    // imagejpeg($rotate);
    imagedestroy($source);
    imagedestroy($rotate);

Answer 5

$destimg = imagecreatefromjpeg("image.png");
$transColor = imagecolorallocatealpha($destimg, 255, 255, 255, 127);
$rotatedImage = imagerotate($destimg, 200, $transColor);
imagesavealpha($rotatedImage, true);
imagepng($rotatedImage,"rotated.png");

Answer 6

Make sure you set imagesavealpha to TRUE in order to preserve transparency. http://www.php.net/manual/en/function.imagesavealpha.php

imagesavealpha($image, TRUE);