PHP 在不裁剪的情况下将上传的图片调整为特定尺寸

Question

我目前有一个脚本，用户可以在其中上传任何尺寸的图像文件。上传的图像通过 ajax 发送到 PHP 脚本，在那里它应该调整大小并保存到服务器。调整大小的过程不应裁剪或扭曲图像，而是通过在边上添加白色来将其调整为特定尺寸，或者 top/bottom 如果它与尺寸不完全匹配。我有这个过程非常适合方形图像 - 但是当尝试修改过程以适用于矩形尺寸时它不再正常运行。

                 $sourceImage = imagecreatefromjpeg("../img/whiteBG.jpg");
                 $dimensions = getimagesize($files["tmp_name"][$i]);
                 $ratio = $dimensions[0] / $dimensions[1]; // width/height

                 $dst_y = 0;
                 $dst_x = 0;

                 //final image should be 600x360
                 if ($ratio > 1) {
                        $width = 600;
                        $height = 360 / $ratio;
                        $dst_y = (360 - $height) / 2;
                 } else {
                        $width = 600 * $ratio;
                        $height = 360;
                        $dst_x = (600 - $width) / 2;
                 }

                 $src = imagecreatefromstring(file_get_contents($files["tmp_name"][$i]));
                 $dst = imagecreatetruecolor($width, $height);
                 imagecopyresampled($dst, $src, 0, 0, 0, 0, $width, $height, $dimensions[0], $dimensions[1]);

                 imagecopymerge($sourceImage, $dst, $dst_x, $dst_y, 0, 0, imagesx($dst), imagesy($dst), 100);
                 $moved = imagepng($sourceImage, $dir . $filename);

输出图像 ($moved) 的最终尺寸应为 600 x 360。相反，最终图像总是失真的。如果上传高图片比例，则最终产品会在宽度方向拉伸。如果上传更宽的图像比例，则它会被压缩并以额外的顶部和底部间距混合。 whiteBG.jpg 只是一张尺寸为 600x360

的普通白色 jpeg

Answer 1

最终更正了这一点。问题是我如何计算和补偿比率。这是纠正问题的最终代码，使用变量使代码在其他情况下更加通用

             $targetWidth = 600;
             $targetHeight = 360;
             $dstY = 0;
             $dstX = 0;
             $ratioFactor = 0;

             $bgImage = imagecreatefromjpeg("../img/bgWhite.jpg");
             $dimensions = getimagesize($files["tmp_name"][$i]);
             $sourceWidth = $dimensions[0];
             $sourceHeight = $dimensions[1];
             $ratio = $sourceWidth / $sourceHeight; // width/height

             //final image should be 600x360
             if ($ratio > 1) {
                    $ratioFactor = $sourceWidth / $targetWidth;
                    $targetHeight = $sourceHeight / $ratioFactor;
                    $dstY = (360 - $targetHeight) / 2;
             } else {
                    $ratioFactor = $sourceHeight / $targetHeight;
                    $targetWidth = $sourceWidth / $ratioFactor;
                    $dstX = (600 - $targetWidth) / 2;
             }

             $source = imagecreatefromstring(file_get_contents($files["tmp_name"][$i]));
             $target = imagecreatetruecolor($targetWidth, $targetHeight);
             imagecopyresampled($target, $source, 0, 0, 0, 0, $targetWidth, $targetHeight, $sourceWidth, $sourceHeight);

             imagecopymerge($bgImage, $target, $dstX, $dstY, 0, 0, imagesx($target), imagesy($target), 100);
             imagepng($bgImage, $dir . $filename);

PHP 在不裁剪的情况下将上传的图片调整为特定尺寸

PHP Resize Uploaded Image To Specific Dimensions Without Cropping

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