PHP GD如何圆形裁剪3个方形图像并合并为1个图像以保持透明度

我有两个源图像，我想：

对每个图像进行圆形裁剪，使圆形外部透明

将所有图像合并/复制回目标透明图像

我已经试过了，但似乎无法保持最终图像的透明度

我正在努力实现这样的目标：

这是我得到的一个输出示例：

这是我的圆形裁剪函数：

    function create_circle( $img_path ) {
    // Attribution: by NerdsOfTech

    // Step 1 - Start with image as layer 1 (canvas).
    if (! $img1 = $this->imageCreateFromAny( $img_path )) {
        return FALSE;
    }

    $x=imagesx($img1);
    $y=imagesy($img1);


    // Step 2 - Create a blank image.
    $img2 = imagecreatetruecolor($x, $y);

    $bg = imagecolorallocate($img2, 255,0,255, 127); // wierdo pink background
    // $bg = imagecolorallocate($img2, 0, 0, 0, 127 ); // white background

    imagefill($img2, 0, 0, $bg);
    imagecolortransparent($img2, $bg);

    // Step 3 - Create the ellipse OR circle mask.
    $e = imagecolorallocate($img2, 255, 255, 255); // black mask color

    // Draw a ellipse mask
    imagefilledellipse ($img2, ($x/2), ($y/2), $x, $y, $e);

    // OR
    // Draw a circle mask
    // $r = $x <= $y ? $x : $y; // use smallest side as radius & center shape
    // imagefilledellipse ($img2, ($x/2), ($y/2), $r, $r, $e);

    // Step 4 - Make shape color transparent
    imagecolortransparent($img2, $e);

    // Step 5 - Merge the mask into canvas with 100 percent opacity
    imagecopymerge($img1, $img2, 0, 0, 0, 0, $x, $y, 100);

    // Step 6 - Make outside border color around circle transparent
    imagecolortransparent($img1, $bg);

    /* Clean up memory */
    imagedestroy($img2);

    return $img1;
}

function show_png_from_image_object( $img_obj ) {
    header ( 'Content-Type: image/png' );

    /* Display PNG with max compression */
    imagepng ( $img_obj, NULL,  9, PNG_ALL_FILTERS);
    imagedestroy ( $img_obj );
}

以下是我的显示功能：

    function create_circle( $img_path ) {
    // Attribution: by NerdsOfTech

    // Step 1 - Start with image as layer 1 (canvas).
    if (! $img1 = $this->imageCreateFromAny( $img_path )) {
        return FALSE;
    }

    $x=imagesx($img1);
    $y=imagesy($img1);


    // Step 2 - Create a blank image.
    $img2 = imagecreatetruecolor($x, $y);

    $bg = imagecolorallocate($img2, 255,0,255, 127); // wierdo pink background
    // $bg = imagecolorallocate($img2, 0, 0, 0, 127 ); // white background

    imagefill($img2, 0, 0, $bg);
    imagecolortransparent($img2, $bg);

    // Step 3 - Create the ellipse OR circle mask.
    $e = imagecolorallocate($img2, 255, 255, 255); // black mask color

    // Draw a ellipse mask
    imagefilledellipse ($img2, ($x/2), ($y/2), $x, $y, $e);

    // OR
    // Draw a circle mask
    // $r = $x <= $y ? $x : $y; // use smallest side as radius & center shape
    // imagefilledellipse ($img2, ($x/2), ($y/2), $r, $r, $e);

    // Step 4 - Make shape color transparent
    imagecolortransparent($img2, $e);

    // Step 5 - Merge the mask into canvas with 100 percent opacity
    imagecopymerge($img1, $img2, 0, 0, 0, 0, $x, $y, 100);

    // Step 6 - Make outside border color around circle transparent
    imagecolortransparent($img1, $bg);

    /* Clean up memory */
    imagedestroy($img2);

    return $img1;
}

function show_png_from_image_object( $img_obj ) {
    header ( 'Content-Type: image/png' );

    /* Display PNG with max compression */
    imagepng ( $img_obj, NULL,  9, PNG_ALL_FILTERS);
    imagedestroy ( $img_obj );
}

我已经把头发拔了两天了，所以任何指点都将不胜感激

---

谢谢，Jason。

我编写了以下类来处理所有必需的图像处理：

class Img
{
    public $img;

    public $transparent;

    public $width;

    public $height;

    public function __construct($img = null)
    {
        if (!empty($img)) {
            $this->img = imagecreatefrompng($img);
            $this->width = imagesx($this->img);
            $this->height = imagesy($this->img);
            $this->setTransparentColour();
        }
    }

    public function create($width, $height, $transparent)
    {
        $this->img = imagecreatetruecolor($width, $height);
        $this->width = $width;
        $this->height =$height;

        $this->setTransparentColour();

        if (true === $transparent) {
            imagefill($this->img, 0, 0, $this->transparent);
        }
    }

    public function setTransparentColour($red = 255, $green = 0, $blue = 255)
    {
        $this->transparent = imagecolorallocate($this->img, $red, $green, $blue);
        imagecolortransparent($this->img, $this->transparent);
    }

    public function circleCrop()
    {
        $mask = imagecreatetruecolor($this->width, $this->height);
        $black = imagecolorallocate($mask, 0, 0, 0);
        $magenta = imagecolorallocate($mask, 255, 0, 255);

        imagefill($mask, 0, 0, $magenta);

        imagefilledellipse(
            $mask,
            ($this->width / 2),
            ($this->height / 2),
            $this->width,
            $this->height,
            $black
        );

        imagecolortransparent($mask, $black);

        imagecopymerge($this->img, $mask, 0, 0, 0, 0, $this->width, $this->height, 100);

        imagedestroy($mask);
    }

    public function merge(Img $in, $dst_x = 0, $dst_y = 0)
    {
        imagecopymerge(
            $this->img,
            $in->img,
            $dst_x,
            $dst_y,
            0,
            0,
            $in->width,
            $in->height,
            100
        );
    }

    public function render()
    {
        header('Content-type: image/png');
        imagepng($this->img);
    }
}

如前所述，该类将只处理PNG文件，但如果需要，您应该能够足够轻松地修改它

示例类用法：

// create a transparent base image that we will merge the cropped images into.
$img = new Img();
$img->create(400, 400, true);

// first image; crop and merge with base.
$img2 = new Img('./crop_1.png');
$img2->circleCrop();
$img->merge($img2, 50, 50);

// second image; crop and merge with base.
$img3 = new Img('./crop_2.png');
$img3->circleCrop();
$img->merge($img3, 25, 200);

$img->render();

这将产生下图（当然，嵌入此处时无法看到透明度，因此请尝试单独打开图像）：

我使用了以下两个源图像：

您可以使用创建的GD包装器来使用php轻松处理图像

$overlay = new Overlay(720, 480, new Color(34,34,36));
$w = $overlay->getWidth();
$h = $overlay->getHeight();

$mi = new CircularShape("./mi.jpg");
$mi->scale(21);
$mi->setAxises(60,60);
$mi->build();

$mali = new CircularShape("./mali.jpg");
$mali->scale(60);
$mali->setAxises(140,140);
$mali->build();

$bach = new CircularShape("./har.jpeg");
$bach->scale(40);
$bach->setAxises(80,80);
$bach->build();

$borderd = new CircularShape(new Overlay($bach->getWidth()+10,$bach->getHeight()+10,new Color(255,255,255)));
$borderd->build();
$bach = $borderd->merge($bach,5,5);

$img = $overlay->merge($mi,$w/2 + 60,120);
$img->merge($mali,170,60);
$img->merge($bach,$w/2,200);

$img->dump(); //this just for demo, but you can use other methods to save this to disk

目前ImageArtist不支持边框，但如果您缺乏创意，可以使用覆盖。 下面是上述代码的输出

---

看看是否可以help@tiGer-不知道这有什么帮助吗？你能添加

create\u polarioid

、

create\u circle

和

show\u png\u from\u image\u object

的代码吗？@tiGer-我已经更新了show\u png\u from\u image\u object函数。create_polaroid不相关，因为它未被使用。我这样调用函数：generate_collage（$img_name_path_array，'CIRCLES'）；