php - 背景变成黑色

Question

我已经尽我所能尝试解决这个问题。我花了一个多小时研究和尝试代码，但没有任何帮助。

此代码执行以下操作。

• 拍摄两张全白图像并重新着色（同时保持透明度）
• 将两个图像合并在一起
• 输出图像（但背景为黑色！！）

有人可以帮助识别和修补导致黑色背景的部分吗？有关脚本示例，请参见以下 URL。

• http://labs.bluefiremedia.net/metro-machine/gd/download-png.php?size=128&padding=29&icon=icons/Application/Add-New.png&bgShape=CircleBG.png&bgColorR=255&bgColorG=0&bgColorB=0&iconColorR=255&iconColorG= 255&图标颜色​​B=255

  $final_image = imagecreatetruecolor($dimensions, $dimensions);
  imagesavealpha($final_image, true);
  
  if($bgShape != '') {
  list($originalWidth, $originalHeight) = getimagesize('../images/' . $bgShape);
  
  $background = imagecreatefrompng('../images/' . $bgShape);
  
  imagefilter($background, IMG_FILTER_BRIGHTNESS, -255);
  imagefilter($background, IMG_FILTER_COLORIZE, $bgColorR, $bgColorG, $bgColorB);
  
  $backgroundImage = imagecreatetruecolor( $dimensions, $dimensions );
  imagealphablending($backgroundImage , false);
  imagesavealpha($backgroundImage , true);
  
  imagecopyresampled($backgroundImage,
      $background,
      0, 0,
      0, 0,
      $dimensions, $dimensions,
      $originalWidth, $originalHeight
  );
  
  imagecopy($final_image, $backgroundImage, 0, 0, 0, 0, $dimensions, $dimensions);
  
  ///
  
  $icon = imagecreatefrompng("../" . $icon);
  
  imagefilter($icon, IMG_FILTER_BRIGHTNESS, -255);
  imagefilter($icon, IMG_FILTER_COLORIZE, $iconColorR, $iconColorG, $iconColorB);
  
  $iconImage = imagecreatetruecolor( $dimensions, $dimensions );
  imagealphablending($iconImage , false);
  imagesavealpha($iconImage , true);
  
  imagecopyresampled($iconImage,
      $icon,
      0, 0,
      0, 0,
      $dimensions, $dimensions,
      $originalWidth, $originalHeight
  );
  
  imagecopy($final_image, $iconImage, 0, 0, 0, 0, $dimensions, $dimensions);
  
  ///
  
  imagealphablending($final_image, true);
  imagesavealpha($final_image, true);
  
  imagepng($final_image, NULL, 0, PNG_NO_FILTER);
  
  header("Content-type: image/png");
  imagedestroy($backgroundImage);
  

Answer 1

设置imagealphablending为 false，用透明颜色填充图像，设置imagealphablending为 true，然后进行复制。

$final_image = imagecreatetruecolor($dimensions, $dimensions);
imagealphablending($final_image, false);
$transparency = imagecolorallocatealpha($final_image,  0, 0, 0, 127);
imagefilledrectangle($final_image, 0, 0, $dimensions, $dimensions, $transparency);
imagesavealpha($final_image, true);
imagealphablending($final_image, true);

// rest of the code