如何使用PHP GD库将不同大小的多个透明png合并到一个图像中而不进行裁剪？

问题描述：

I would like to merge multiple pngs with transparent background into one image. Images have different sizes and because of this, when images are placed over the top of each other, only within the size of the uppermost image are shown the parts of the merged images.

It's like the last image applies like a mask for the images merged before. I would like to see all the images merged with their original size, without cropping the parts hanging over the size of the last image.

Here is the code I'm using currently:

$images = array();
    foreach (scandir($this->img_dir) as $key => $dirname) {
        if(!strstr($dirname, "."))
        {
            if(isset($_GET[$dirname])) 
            {
                foreach ($this->layer_order as $lkey => $order) {
                    if($lkey == $dirname)
                        $images[$order] = glob($this->img_dir . "/" . $dirname . "/" . $_GET[$dirname] . ".png");
                }
            }
        }
    }


    $destination = imagecreatetruecolor(458, 600);


    imagealphablending($destination, true);
    imagesavealpha($destination, true);

    ksort($images);
    foreach($images as $key => $value) {        
        foreach ($value as $fn) {
            // Load image
            $source = imagecreatefrompng($fn);
            //$source = $this->resize_image($source, 50, 50, 2);

            // Copy over image
            imagecopy($destination, $source, 10, 50, 0, 0, 458, 600);

            // Free memory
            imagedestroy($source);
        }
    }

    return $destination;

我想将多个透明背景的png合并到一个图像中。图像具有不同的尺寸，因此，当图像被放置在彼此的顶部上时，仅在最上面的图像的尺寸内显示合并图像的部分。 p>

这就像上一张图像适用于之前合并的图像的蒙版一样。我希望看到所有图像都与原始大小合并，而不会裁剪掉最后一个图像大小的部分。 p>

这是我目前正在使用的代码： p>

  $ images = array（）; 
 foreach（scandir（$ this-＆gt; img_dir）as $ key =＆gt; $ dirname）{
 if（！strstr（$  dirname，“。”））
 {
 if ifset（$ _ GET [$ dirname]））
 {
 foreach（$ this-＆gt; layer_order as $ lkey =＆gt; $ order）{
 if  （$ lkey == $ dirname）
 $ images [$ order] = glob（$ this-＆gt; img_dir。“/”。$ dirname。“/”。$ _GET [$ dirname]。“。png”）;  
} 
} 
} 
} 
 
 
 $ destination = imagecreatetruecolor（458,600）; 
 
 
 imagealphablending（$ destination，true）; 
 imagesavealpha（$ destination，true  ）; 
 
 ksort（$ images）; 
 foreach（$ images as $ key =＆gt; $ value）{
 foreach（$ value as $ fn）{
 // Load image 
 $ source =  imagecreatefromp  ng（$ fn）; 
 // $ source = $ this-＆gt; resize_image（$ source，50,50,2）; 
 
 //复制图像
 imagecopy（$ destination，$ source，10  ，50,0,0,458,600）; 
 
 //空闲内存
 imagedestroy（$ source）; 
} 
} 
 
返回$ destination; 
  code>   pre> 
  div>

答

I don't know if this is the best solution for what I tried to achive, but after several attempts and some research I used a fairly simple method to avoid the last image in the merging queue, mask the other images with it's relatively small size. This way every image will be merged and positioned accordingly the user wants, inside the specified canvas size, with their transparency.

I post the whole content of the function in case if someone needs a similar solution. This is a function inside a class.

    $images = array();

    // Foreach loop to set images order and creating an array with image paths using params from $_GET before merging
    foreach (scandir($this->img_dir) as $key => $dirname) {
        if(!strstr($dirname, "."))
        {
            if(isset($_GET[$dirname])) 
            {
                foreach ($this->layer_order as $lkey => $order) {
                    if($lkey == $dirname) {
                        $imageArray = glob($this->img_dir . "/" . $dirname . "/" . ($dirname == "door" && isset($_GET['type']) ? $_GET['type']."/" : "") . $_GET[$dirname] . ".png");
                        foreach ($imageArray as $imgPath) {
                            $images[$order] = $imgPath;
                        }
                    }       
                }
            }
        }
    }

    // Allocate new image
    $destination = imagecreatetruecolor($this->canvas_width, $this->canvas_height);

    imagealphablending($destination, false);
    $col = imagecolorallocatealpha($destination, 255, 255, 255, 127);
    imagefilledrectangle($destination, 0, 0, $this->canvas_width, $this->canvas_height, $col);
    imagealphablending($destination, true);

    // Sort order
    ksort($images);

    // Merging images
    foreach($images as $key => $fn) {

        // Load image
        if(strstr($fn, "handle")) 
        {
            $source = $this->resizePng($fn, 0.18, 100, 205);
            imagecopy($destination, $source, 0, 0, 0, 0, $this->canvas_width, $this->canvas_height);
        }
        elseif (strstr($fn, "glass")) 
        {
            // Create a background image by filling a canvas with small image tiles. Params: $file, $shrink_ratio_percent, $column_size, $stretch
            $source = $this->multiplyMergeAndResizePngs($fn, 0.2095, 3, 3.6);
            // Applying mask on images based on black and white patterns
            if ($this->glass_mask)
                $source = $this->createMask($source, $this->glass_mask);
            imagecopy($destination, $source, 118, 28, 0, 0, $this->canvas_width, $this->canvas_height);
        }
        elseif (strstr($fn, "door")) 
        {    
            $source = imagecreatefrompng($fn);
            imagecopy($destination, $source, 32, 0, 0, 0, $this->canvas_width, $this->canvas_height);
        } else {
            $source = imagecreatefrompng($fn);
            imagecopy($destination, $source, 0, 0, 0, 0, $this->canvas_width, $this->canvas_height);
        }

        imagealphablending($destination, true);

        // Free memory
        imagedestroy($source);
    }

    return $destination;

如何使用PHP GD库将不同大小的多个透明png合并到一个图像中而不进行裁剪？

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