Php 方形缩略前进

我有一个php缩略图函数。它的工作原理您可以在下面查看：

public static function makeThumb($source, $destination, $thumb_width){

        $size   = getimagesize($source);
        $width  = $size[0];
        $height = $size[1];
        $x      = 0;
        $y      = 0;

        $status  = false;

        if ($width > $height) {
            $x      = ceil(($width - $height) / 2);
            $width  = $height;
        } else if ($height > $width) {
            $y      = ceil(($height - $width) / 2);
            $height = $width;
        }

        $new_image = imagecreatetruecolor($thumb_width,$thumb_width) or die ('Cannot Initialize new GD image stream');
        $extension = self::get_file_extension($source);
        if ($extension == 'jpg' || $extension == 'jpeg')
            $image = imagecreatefromjpeg($source);
        if ($extension == 'gif')
            $image = imagecreatefromgif($source);
        if ($extension == 'png')
            $image = imagecreatefrompng($source);

        imagecopyresampled($new_image,$image,0,0,$x,$y,$thumb_width,$thumb_width,$width,$height);


        if ($extension == 'jpg' || $extension == 'jpeg')
            $status = @imagejpeg($new_image, $destination);
        if ($extension == 'gif')
            $status = @imagegif($new_image, $destination);  
        if ($extension == 'png')
            $status = @imagepng($new_image, $destination);      

        imagedestroy($image);

        return $status;
    }

请检查以下图片（其工作原理）：

问题：我怎样才能得到这张图片（这个拇指来自photoshop）

---

使用错误的拇指宽度（没有拇指高度！）会产生这种方形结果

 imagecopyresampled($new_image,$image,0,0,$x,$y,$thumb_width,$thumb_width,$width,$height);

根据PHP手册（），imagecopyresampled复制原始图像的一个调整大小的区域。但是你想要整本原作。你可以

 imagecopyresampled($new_image,$image,0,0,0,0,$thumb_width,$thumb_height,$width,$height);

您需要先计算$thumbheight-height*thumbwidth/width，或者您可以将原始宽度和高度除以一个设定值

正如下面的注释所示，此函数中使用的参数相当混乱。所以我添加了一个解释，希望你能创造你喜欢的

imagecopyresampled

将图像的矩形部分复制并调整大小，使其成为新图像的矩形部分。因此，所有的参数都需要两次-对于原始图像和新图像。绘图可能有助于：

      $image                  $new_image                
+----------------+        +----------------+
|   source img   |        | destination img|
|                |        |                |
|                |        |    +--------+  |
|        +------+|        |    |  part  |  |
|        | part ||        |    |  copy  |  |
|        |      ||        |    +--------+  |
|        +------+|        |                |
+----------------+        +----------------+

争论是

   $dst_image        the new image (dst = destination)
   $src_image        the old image (src = source)
   $dst_x , $dst_y   top left of destination area
   $src_x , $src_y   top left of source area
   $dst_w , $dst_h   width and height of destination area
   $src_w , $src_h   width and height of source area

如果您试图将整个源图像复制到一个新的大小，在一个新的目标图像中，它们将类似于

   $dst_image        the new image (dst = destination)
   $src_image        the old image (src = source)
   0 , 0             top left of destination area
   0 , 0             top left of source area
   $dst_w , $dst_h   new width and height of thumb
   $width , $height  width and height of whole source image

---

但是，由于我不确定您希望缩略图的大小，我不得不让您找到正确的值。

正确的解决方案是：

public static function makeThumb($source, $destination, $square_size=167, $quality=90) {

        $status  = false;
        list($width, $height, $type, $attr) = getimagesize($source);

        if($width> $height) {
           $width_t =  $square_size;
           $height_t    =   round($height/$width*$square_size);
           $off_y       =   ceil(($width_t-$height_t)/2);
           $off_x       =   0;

        } elseif($height> $width) {

           $height_t    =   $square_size;
           $width_t =   round($width/$height*$square_size);
           $off_x       =   ceil(($height_t-$width_t)/2);
           $off_y       =   0;

        } else {

            $width_t    =   $height_t   =   $square_size;
            $off_x      =   $off_y      =   0;
        }

        $thumb_p    = imagecreatetruecolor($square_size, $square_size);

        $extension  = self::get_file_extension($source);

        if($extension == "gif" or $extension == "png"){

            imagecolortransparent($thumb_p, imagecolorallocatealpha($thumb_p, 0, 0, 0, 127));
            imagealphablending($thumb_p, false);
            imagesavealpha($thumb_p, true);
        }   

        if ($extension == 'jpg' || $extension == 'jpeg')
            $thumb = imagecreatefromjpeg($source);
        if ($extension == 'gif')
            $thumb = imagecreatefromgif($source);
        if ($extension == 'png')
            $thumb = imagecreatefrompng($source);

        $bg = imagecolorallocate ( $thumb_p, 255, 255, 255 );
        imagefill ($thumb_p, 0, 0, $bg);

        imagecopyresampled($thumb_p, $thumb, $off_x, $off_y, 0, 0, $width_t, $height_t, $width, $height);

        if ($extension == 'jpg' || $extension == 'jpeg')
            $status = @imagejpeg($thumb_p,$destination,$quality);
        if ($extension == 'gif')
            $status = @imagegif($thumb_p,$destination,$quality);
        if ($extension == 'png')
            $status = @imagepng($thumb_p,$destination,9);

        imagedestroy($thumb);
        imagedestroy($thumb_p);

        return $status;
    }

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使用php进行多种选择。我知道，但需要GD解决方案。谢谢。如果它需要是正方形，并且看起来像你的photoshop示例，那么不，我也没有解决方案：）我想说-你的photoshop是矩形的，但是你说你想要一个正方形的图像。所以我没办法解决。但我已经扩展了我的答案，以更清楚地解释参数是如何工作的。希望这能给你解决问题的方法。