PHP - 如何將矩形圖像轉換爲方形圖像？

Question

如何在PHP中將矩形圖像更改爲方形的頭像，以便無論上傳圖像的分辨率如何，都可以調整爲集中的42 x 42像素頭像。這是我使用的PHP代碼。任何人都可以建議。

<?php 
//Name you want to save your file as 
$save = 'myfile1.jpg'; 

$file = 'original1.jpg'; 
echo "Creating file: $save"; 
$size = 0.45; 
header('Content-type: image/jpeg') ; 
list($width, $height) = getimagesize($file) ; 
$modwidth = $width * $size; 
$modheight = $height * $size; 
$tn = imagecreatetruecolor($modwidth, $modheight) ; 
$image = imagecreatefromjpeg($file) ; 
imagecopyresampled($tn, $image, 0, 0, 0, 0, $modwidth, $modheight, $width, $height) ; 

// Here we are saving the .jpg, you can make this gif or png if you want 
//the file name is set above, and the quality is set to 100% 
imagejpeg($tn, $save, 100) ; 
?> 

Answer 1

首先，您需要知道尺寸爲$ x和$ y的矩形的中心正方形在哪裏。

// horizontal rectangle 
if ($x > $y) { 
    $square = $y;    // $square: square side length 
    $offsetX = ($x - $y)/2; // x offset based on the rectangle 
    $offsetY = 0;    // y offset based on the rectangle 
} 
// vertical rectangle 
elseif ($y > $x) { 
    $square = $x; 
    $offsetX = 0; 
    $offsetY = ($y - $x)/2; 
} 
// it's already a square 
else { 
    $square = $x; 
    $offsetX = $offsetY = 0; 
} 

現在我們可以從它建立一個正方形，只需要調整它到42x42。像這樣的東西應該工作：

list($x, $y) = getimagesize($file); 

// code snippet from above goes here 
// so we get the square side and the offsets 

$endSize = 42; 
$tn = imagecreatetruecolor($endSize, $endSize); 
imagecopyresampled($tn, $image, 0, 0, $offsetX, $offsetY, $endSize, $endSize, $square, $square); 

---

所以，如果我們有一個矩形圖像100x80，代碼會找出大廣場大小爲80 x偏移量是10，y偏移爲0粗略地，它看起來像這樣：

100 
----------- 
|   | 
|   | 80 
|   | 
----------- 

    | 
    V 

    80 
---------    42 
|  |    ----- 
|  | 80 ---> | | 42 
|  |    ----- 
--------- 

我們裁剪從原來的長方形大廣場後，我們只需將它縮小到最終大小，這是你的情況42。

---

只是測試和完美的作品，一定要去除回聲線，如果你打算輸出圖像到瀏覽器（與頭部相結合）。

Answer 2

我不知道是否有人正在尋找這個，但我需要有一個600 x 600平方的圖像。

來源可以是任何矩形圖像，我需要維持原始圖像的比例並將原始矩形圖像置於600 x 600平方的白色圖像中。

這

• SRC_FILE：源圖像的URL
• destination_file：所在的路徑目標文件將被保存。
• square_dimensions（像素）。我需要600，但可以是任何價值。

• jpeg_quality：Quality（0，100）。我用默認的90

  function square_thumbnail_with_proportion($src_file,$destination_file,$square_dimensions,$jpeg_quality=90) 
  { 
      // Step one: Rezise with proportion the src_file *** I found this in many places. 
  
      $src_img=imagecreatefromjpeg($src_file); 
  
      $old_x=imageSX($src_img); 
      $old_y=imageSY($src_img); 
  
      $ratio1=$old_x/$square_dimensions; 
      $ratio2=$old_y/$square_dimensions; 
  
      if($ratio1>$ratio2) 
      { 
       $thumb_w=$square_dimensions; 
       $thumb_h=$old_y/$ratio1; 
      } 
      else  
      { 
       $thumb_h=$square_dimensions; 
       $thumb_w=$old_x/$ratio2; 
      } 
  
      // we create a new image with the new dimmensions 
      $smaller_image_with_proportions=ImageCreateTrueColor($thumb_w,$thumb_h); 
  
      // resize the big image to the new created one 
      imagecopyresampled($smaller_image_with_proportions,$src_img,0,0,0,0,$thumb_w,$thumb_h,$old_x,$old_y); 
  
      // *** End of Step one *** 
  
      // Step Two (this is new): "Copy and Paste" the $smaller_image_with_proportions in the center of a white image of the desired square dimensions 
  
      // Create image of $square_dimensions x $square_dimensions in white color (white background) 
      $final_image = imagecreatetruecolor($square_dimensions, $square_dimensions); 
      $bg = imagecolorallocate ($final_image, 255, 255, 255); 
      imagefilledrectangle($final_image,0,0,$square_dimensions,$square_dimensions,$bg); 
  
      // need to center the small image in the squared new white image 
      if($thumb_w>$thumb_h) 
      { 
       // more width than height we have to center height 
       $dst_x=0; 
       $dst_y=($square_dimensions-$thumb_h)/2; 
      } 
      elseif($thumb_h>$thumb_w) 
      { 
       // more height than width we have to center width 
       $dst_x=($square_dimensions-$thumb_w)/2; 
       $dst_y=0; 
  
      } 
      else 
      { 
       $dst_x=0; 
       $dst_y=0; 
      } 
  
      $src_x=0; // we copy the src image complete 
      $src_y=0; // we copy the src image complete 
  
      $src_w=$thumb_w; // we copy the src image complete 
      $src_h=$thumb_h; // we copy the src image complete 
  
      $pct=100; // 100% over the white color ... here you can use transparency. 100 is no transparency. 
  
      imagecopymerge($final_image,$smaller_image_with_proportions,$dst_x,$dst_y,$src_x,$src_y,$src_w,$src_h,$pct); 
  
      imagejpeg($final_image,$destination_file,$jpeg_quality); 
  
      // destroy aux images (free memory) 
      imagedestroy($src_img); 
      imagedestroy($smaller_image_with_proportions); 
      imagedestroy($final_image); 
  }