调整图像的最大宽度和高度

Question

我一直在寻找遍及互联网寻找解决方案。我使用这个SimpleImage.php类来调整我在这里找到的图像的大小（http://www.white-hat-web-design.co.uk/articles/php-image-resizing.php）。到目前为止，一切正常。如果我尝试重新调整图像的大小以适应其高度或宽度，它正在完成其工作。但是，这只适用于我试图一次调整图像大小的情况。假设我的图像的原始尺寸是1400x1100，并且我想将其高度调整为800.这将使我得到某些数字xx的结果。反之亦然。

我的目标是根据我传递的最大宽度和最大高度调整图像大小。

事情是这样的：

$image = new SimpleImage(); 
      $image->load($image_url); 
      $image->resizeToWidthHeight(MAX-WIDTH, MAX-HEIGHT); 
      $image->save('photo.png'); 

这里是我的SimpleImage.php类

<?php 
    class SimpleImage { 
    var $image; 
    var $image_type; 

    function load($filename) { 
     $image_info = getimagesize($filename); 
     $this->image_type = $image_info[2]; 
     if($this->image_type == IMAGETYPE_JPEG) { 
      $this->image = imagecreatefromjpeg($filename); 
     } elseif($this->image_type == IMAGETYPE_GIF) { 
      $this->image = imagecreatefromgif($filename); 
     } elseif($this->image_type == IMAGETYPE_PNG) { 
      $this->image = imagecreatefrompng($filename); 
     } 
    } 
    function save($filename, $image_type=IMAGETYPE_JPEG, $compression=75, $permissions=null) { 
     if($image_type == IMAGETYPE_JPEG) { 
      imagejpeg($this->image,$filename,$compression); 
     } elseif($image_type == IMAGETYPE_GIF) { 
      imagegif($this->image,$filename); 
     } elseif($image_type == IMAGETYPE_PNG) { 
      imagepng($this->image,$filename); 
     } 
     if($permissions != null) { 
      chmod($filename,$permissions); 
     } 
    } 

    function output($image_type=IMAGETYPE_JPEG) { 
     if($image_type == IMAGETYPE_JPEG) { 
      imagejpeg($this->image); 
     } elseif($image_type == IMAGETYPE_GIF) { 
      imagegif($this->image); 
     } elseif($image_type == IMAGETYPE_PNG) { 
      imageAlphaBlending($this->image, true); 
      imageSaveAlpha($this->image, true); 
      imagepng($this->image); 
     } 
    } 

    function getWidth() { 
     return imagesx($this->image); 
    } 
    function getHeight() { 
     return imagesy($this->image); 
    } 
    function resizeToHeight($height) { 
     $ratio = $height/$this->getHeight(); 
     $width = $this->getWidth() * $ratio; 
     $this->resize($width,$height); 
    } 
    function resizeToWidth($width) { 
     $ratio = $width/$this->getWidth(); 
     $height = $this->getheight() * $ratio; 
     $this->resize($width,$height); 
    } 
    function scale($scale) { 
     $width = $this->getWidth() * $scale/100; 
     $height = $this->getheight() * $scale/100; 
     $this->resize($width,$height); 
    } 


    function resize($width,$height) { 

     // ADDED CODE IS HERE - NOT SURE WHY IT DOESN'T WORK FOR PNG 

     // Setup new image 
     $new_image = imagecreatetruecolor($width, $height); 
     // These parameters are required for handling PNG files. 
     imagealphablending($new_image, false); 
     imagesavealpha($new_image,true); 
     $transparent = imagecolorallocatealpha($new_image, 255, 255, 255, 127); 
     imagefilledrectangle($new_image, 0, 0, $width, $height, $transparent); 
     // Resize image 
     imagecopyresampled($new_image, $this->image, 0, 0, 0, 0, $width, $height, $this->getWidth(), $this->getHeight()); 
     $this->image = $new_image; 
    } 
} 

?> 

Answer 1

如果你的图像变化的尺寸：4〜16：你从3去9，您需要在某处应用某种作物。

根据比例找出哪个维度最小，调整该特性的大小然后裁剪其他维度。

---

以我的经验规模永远是错的。我建议你从图书馆中删除它。调整大小+作物是要走的路。

你可以写一个函数像cropTo($newX, $newY)