QUESTION Upload png image

[smdp-1971]

When upload image is it possible to get a transparent background PNG image. Now it looks like this (black background)?

Tnx

[img]jpg imagescertificity.com[/img]

[shawn_a]

It is transparent, that's just the background. Use css to turn it off with the admincss plugin
.jcrop-holder{
background-color: #000;
}


oh nm that was fixed in 3.4, still a bug in 3.3x, when saving the thumbnail loses transparency, which is a separate issue.
The image script had to be modified to preserve transparency. Ill see if it can be patched in or not.

[shawn_a]

replace and add these functions to admin/inc/imagemanipulation.php

PHP Code:

    /**
     * Private method to run the imagecopyresampled() function with the parameters that have been set up.
     * This method is used by the save() and show() methods.
     */
    private function createResampledImage()
    {
        /* change ImageCreateTrueColor to ImageCreate if your GD not supported ImageCreateTrueColor function*/
        if ( isset($this->image["sizex_thumb"]) && isset($this->image["sizey_thumb"]) ) {        
            $this->image["des"] = ImageCreateTrueColor($this->image["sizex_thumb"], $this->image["sizey_thumb"]);
            $this->preserveAlpha();            
            imagecopyresampled($this->image["des"], $this->image["src"], 0, 0, $this->image["targetx"], $this->image["targety"], $this->image["sizex_thumb"], $this->image["sizey_thumb"], $this->image["sizex"], $this->image["sizey"]);
        } else {
            $this->image["des"] = ImageCreateTrueColor($this->image["sizex"], $this->image["sizey"]);
            $this->preserveAlpha();            
            imagecopyresampled($this->image["des"], $this->image["src"], 0, 0, $this->image["targetx"], $this->image["targety"], $this->image["sizex"], $this->image["sizey"], $this->image["sizex"], $this->image["sizey"]);
        }    
    }
    
    /**
     * preserve alpha channel
     * @return boolean true:enable transparency alpha blending
     */
    private function preserveAlpha($bool=true){
        imagealphablending($this->image["des"], !$bool);
        imagesavealpha($this->image["des"], $bool);        
    } 


the preserveAlpha calls being the fix