[SOLVED] Change image filetype on upload?

[Dragen]

Hi,

I've got a form which uploads an image to the server.

Is it possible to change the image type during the upload?

 

I want the user to be able to upload images that are .gif .jpg or .png, but when uploaded, if they are .gif or .jpg, have been changed to .png.

 

Is this possible?

[clay1]

You could try reading this: http://devzone.zend.com/article/1269

 

http://php.net/manual/en/function.imagepng.php

[Dragen]

Thanks for that, but I'm getting some strange results.

 

Here's my code:

	/**
 * Creates a base image from the img url and returns it.
 */
private function createBase(){
	$src_img = NULL;
	switch($this->getType()){
		case 'png':
			$src_img = imagecreatefrompng($this->getImage());
		break;
		case 'gif':
			$src_img = imagecreatefromgif($this->getImage());
		break;
		default:
			$src_img = imagecreatefromjpeg($this->getImage());
		break;
	}
	return $src_img;
}

/**
 * Creates the resampled image that will be used
 */
private static function resampleImage($src_img, $dimg){
	$w = imagesx($src_img);
	$h = imagesy($src_img);
	imagecopyresampled($dimg, $src_img, 0, 0, 0, 0, $w, $h, $w, $h);
}

private function replaceImage(){
	if($this->getType() == 'png'){
		return true;
	}else{
		//checks images exists and creates the base source image
		if($this->imageExists() && ($src_img = $this->createBase())){
			$dimg = imagecreatetruecolor(imagesx($src_img), imagesy($src_img));
			imagealphablending($dimg, false);
			$colorTransparent = imagecolorallocatealpha($dimg, 0, 0, 0, 127);
			imagefill($dimg, 0, 0, $colorTransparent);
			imagesavealpha($dimg, true);

			//resamples the image
			$this->resampleImage($src_img, $dimg);

			//getImageNoType gets the image path, without the filetype, so I can add .png to the end
			if(imagepng($dimg, $this->getImageNoType() . '.png')){
				@imagedestroy($dimg);
				@imagedestroy($src_img);
				unlink($this->getImage());
				return true;
			}
		}
		return false;
	}
}

 

At first glance this appears to work, as it successfully creates the image, with a .png extension, but when trying to access it through PHP GD library, using imagecreatefrompng(), it throws up the following error:

Warning: imagecreatefrompng() [function.imagecreatefrompng]: 'C:/Program Files/wamp/www/images/links/2_5.png' is not a valid PNG file in C:\Program Files\wamp\www\incs\thumbs.php on line 60

 

So it appears that it has saved the file, but not encoded it as a png.

 

 

EDIT:

In fact, checking it in firefox, pageinfo, it states the filetype is .jpg

[rajivgonsalves]

use the imagepng after that

   /**
    * Creates a base image from the img url and returns it.
    */
   private function createBase(){
      $src_img = NULL;
      switch($this->getType()){
         case 'png':
            $src_img = imagecreatefrompng($this->getImage());
         break;
         case 'gif':
            $src_img = imagecreatefromgif($this->getImage());
         break;
         default:
            $src_img = imagecreatefromjpeg($this->getImage());
         break;
      }
      return imagepng($src_img);
   }

 

hope it works 

[Dragen]

Okay, thanks for the replies!

Its working fine now, the problem was on my end. I'd missed out a call to a function so it wasn't doing everything...

The code I had below works perfectly.

 

Thanks!