php - 如何使用 PHP ImageMagic/Imagick 从 JSON/数据数组(宽度、高度、x、y、角度)创建大型(高质量 300dpi)图像

Question

我使用 FabricJs 在 Canvas 上创建了一个带有一些图片和文本的设计 (270x470)，然后我通过 fabricJS 的 canvas.toJSON() 方法以 JSON 格式导出所有图片/文本信息现在我需要在使用 Imagick 的 PHP 中的高质量 (2790x4560) 图像。

用于上述设计的 JSON dataArray 包含所有对象的信息，如大小、位置、角度等。

{
"width": "2790",
"height": "4560",
"json_data": {
    "objects": [{
            "type": "image",
            "originX": "left",
            "originY": "top",
            "left": "5",
            "top": "105",
            "width": "260",
            "height": "260",
            "scaleX": "1",
            "scaleY": "1",
            "angle": "0",
            "opacity": "1",
            "src": "http:\\example.com/images/098f20be9fb7b66d00cb573acc771e99.JPG",
        }, {
            "type": "image",
            "originX": "left",
            "originY": "top",
            "left": "5",
            "top": "229.5",
            "width": "260",
            "height": "11",
            "scaleX": "1",
            "scaleY": "1",
            "angle": "0",
            "opacity": "1",
            "src": "http:\\example.com/images/aeced466089d875a7c0dc2467d179e58.png",
        }, {
            "type": "image",
            "originX": "left",
            "originY": "top",
            "left": "51.07",
            "top": "135.58",
            "width": "260",
            "height": "11",
            "scaleX": "1",
            "scaleY": "1",
            "angle": "47.41",
            "opacity": "1",
            "src": "http:\\example.com/images/910ce024d984b6419d708354bf3641a3.png",
        }, {
            "type": "image",
            "originX": "left",
            "originY": "top",
            "left": "139.71",
            "top": "104.97",
            "width": "260",
            "height": "11",
            "scaleX": "1",
            "scaleY": "1",
            "angle": "89.65",
            "opacity": "1",
            "src": "http:\\example.com/images/88e096a82e5f8a503a71233addaff64c.png",
        }, {
            "type": "image",
            "originX": "left",
            "originY": "top",
            "left": "230.78",
            "top": "146.93",
            "width": "260",
            "height": "11",
            "scaleX": "1",
            "scaleY": "1",
            "angle": "134.98",
            "src": "http:\\example.com/images/d2c0ec738c1fec827381cfeb600bd87d.png",
        }, {
            "type": "image",
            "originX": "left",
            "originY": "top",
            "left": "265.01",
            "top": "240.19",
            "width": "260",
            "height": "11",
            "scaleX": "1",
            "scaleY": "1",
            "angle": "179.86",
            "opacity": "1",
            "src": "http:\\example.com/images/3f0bc771261860d917e0ad6d09cb2064.png",
        }],
    "background": "#FF00FF"
}}

这是我的代码片段，用于使用 JSON dataArray 在 PHP 中生成高质量图像

error_reporting(E_ALL | E_STRICT);

try {
  $id = $_GET['id']; // Design ID

  define('DS', DIRECTORY_SEPARATOR);

  $jsonDir = dirname(__FILE__) . DS . 'media' . DS . 'designs';
  $printData = json_decode(file_get_contents($jsonDir . DS . $id . '.json'));

  } catch (Exception $e) {
     echo $e->getMessage();
  }

try {
   $print = new Imagick();
   $print->setResolution(300, 300);
   $background = (empty($printData->json_data->background)) ? 'transparent' : $printData->json_data->background;
   $print->newImage($printData->width, $printData->height, new ImagickPixel($background));

   $print->setImageFormat('png32');
   $print->setImageUnits(imagick::RESOLUTION_PIXELSPERCENTIMETER);
} catch (Exception $e) {
   echo $e->getMessage();
}

// Re-Scaling each Image/Text for Larger Canvas/Image 
foreach ($printData->json_data->objects as $i => $object) {

   if ($object->type == 'image') {
        addImage($object, $print, $printData);
   } else {
        addText($object, $print, $printData);
   }
}


try {
   // Saving High Quality Image in (300 dpi)
   $fileDir = dirname(__FILE__) . DS . 'media' . DS . 'prints';

   if (!file_exists($fileDir) || !is_dir($fileDir)) {
       if (!mkdir($fileDir))
           die("Could not create directory: {$fileDir}\n");
   }
   $saved = $print->writeimage($fileDir . DS . $id . '.png');
   header('Content-type: image/png');
   echo $print;
 } catch (Exception $e) {
      echo $e->getMessage();
 }

---

addImage();

function addImage($object, $print, $printData) {

    try {
        $widthScale = ($printData->width / 270);
        $heightScale = ($printData->height / 470);
        $fileDir = dirname(__FILE__) . DS . 'media' . DS . 'original' . DS;
        $src = new Imagick($fileDir . basename($object->src));

        $size = $src->getImageGeometry();

        $resizeWidth = ($object->width * $object->scaleX) * $widthScale;
        $resizeHeight = ($object->height * $object->scaleY) * $heightScale;
        $src->resizeImage($resizeWidth, $resizeHeight, Imagick::FILTER_LANCZOS, 1);
        $sizeAfterResize = $src->getImageGeometry();

        $src->rotateImage(new ImagickPixel('none'), $object->angle);
        $sizeAfterRotate = $src->getImageGeometry();


        if (!$object->angle) {
            $left = $object->left * $widthScale;
            $top = $object->top * $heightScale;
        } else {

            switch ($object->angle) {
                case $object->angle > 315:
                    $left = ($object->left * $widthScale);
                    $top = ($object->top * $heightScale);
                    break;
                case $object->angle > 270:
                    $left = ($object->left * $widthScale);
                    $top = ($object->top * $heightScale);

                    break;
                case $object->angle > 225:
                    $left = ($object->left * $widthScale);
                    $top = ($object->top * $heightScale);
                    break;
                case $object->angle > 180:
                    $left = ($object->left * $widthScale);
                    $top = ($object->top * $heightScale);
                    break;
                case $object->angle > 135:
                    $left = ($object->left * $widthScale);
                    $top = ($object->top * $heightScale);
                    break;
                case $object->angle > 90:
                    $left = ($object->left * $heightScale) - ($sizeAfterRotate['width'] / 2);
                    $top = ($object->top * $heightScale) - ($sizeAfterRotate['width'] / 2);
                    break;
                case $object->angle > 45:
                    $left = ($object->left * $widthScale) - $size['height'] * $widthScale;
                    $top = ($object->top * $heightScale) - $size['height'] * $heightScale;
                    break;

                default:
                    $left = $object->left * $widthScale;
                    $top = $object->top * $heightScale;

                    break;
            }
        }

        $print->compositeImage($src, Imagick::COMPOSITE_DEFAULT, $left, $top);
    } catch (Exception $e) {
        echo $e->getMessage();
    }
}

---

我的输出结果 (90%) 与上述解决方案相同，但正如我们所见，一些图像(蓝色数字线)没有放置在应该看起来像第一个设计图像的确切位置

基本上我想做的是，“在循环中调用 addImage 方法进行缩放 - 旋转 - 将每个图像定位在打印图像上 (300DPi)

我不确定在 Imagick 中旋转图像后我缺少什么来获得精确的偏移量(新的 x，y 坐标/位置/左上角)或者我在 Scale 之后旋转对象然后合成

或者可能是像 Math.PI 这样的数学公式 :)

问题是: 缩放后如何根据旋转度数/角度计算新的偏移量/位置？

我希望发布的片段对每个人都有用。

Answer 1

这不是一个完整的答案，但你完全错了。

Fabric.js 已经有一种方法可以使用 canvas.toSVG() 将 Canvas 保存为 SVG 格式。功能。 Imagick 可以打开 SVG 文件并将它们转换为您想要的任何质量的 PNG。

尝试包含图像中包含的位图时会出现问题，例如

"src": "http:\\example.com/images/3f0bc771261860d917e0ad6d09cb2064.png",

我强烈建议您自己在服务器上下载这些，而不是让 Imagick 下载它们。这不仅可以让您更好地控制可能发生的任何错误，还可以限制一些安全风险。允许人们从您的服务器中下载任意数据，然后让存在许多内存访问错误的库使用该数据不是一个好主意。

执行此操作的一般方法是在 fabric.js 创建 SVG 之前将图像的 src 替换为对本地文件名的引用，或者您可以在它被转换后更加hacky - 当您执行此替换会生成需要从远程服务器下载的文件列表。

实际的实现细节留给 OP 练习。

顺便说一句，很有可能有人已经这样做了……你彻底搜索过packagist/github吗？