Question

这是我的代码，但我不知道为什么，但是当我上传垂直图像时，它会调整大小并且我会在两侧看到两条黑色条纹。对于宽图像，它在大多数时间都能很好地工作，但是对于一些图像，我也会得到黑色条纹。我该如何解决？

我的目的是裁剪每个图像，水平只是一个提示以适合我的盒子，垂直我想裁剪，所以宽度是相同的，它们没有被切割的顶部和底部。

$thumb_height  = 200;
$thumb_width   = 300;

    $thumb = imagecreatetruecolor($thumb_width, $thumb_height);
    if($width >= $height) {
       // If image is wider than thumbnail (in aspect ratio sense)
       $new_height = $thumb_height;
       $new_width = $width / ($height / $thumb_height);
    } else {
       // If the thumbnail is wider than the image
       $new_width = $thumb_width;
       $new_height = $height / ($width / $thumb_width);
    }
    $output_filename_mid = 'uploads/'.IMG_L.$fileName;      
    imagecopyresampled($thumb,
                       $image,
                       0 - ($new_width - $thumb_width) / 2, // Center the image horizontally
                       0 - ($new_height - $thumb_height) / 2, // Center the image vertically
                       0, 0,
                       $new_width, $new_height,
                       $width, $height);
    imagejpeg($thumb, $output_filename_mid, 85);

Answer 1

你快到了。您已经发现需要确定旧高度和目标高度之间的比率，以调整要裁剪的边的大小。但是，您需要根据目标比率来确定这一点。

if(($width / $height) > ($thumb_width / $thumb_height)) {
   // If image is wider than thumbnail (in aspect ratio sense)
   $new_height = $thumb_height;
   $new_width = $width / ($height / $thumb_height);
} else {
   // If the thumbnail is wider than the image
   $new_width = $thumb_width;
   $new_height = $height / ($width / $thumb_width);
}

Answer 2

我实际上正在努力解决这个问题。这是我的代码非常类似于您的代码。你能自己找出差异/问题吗？

我的代码100％工作，完全符合您的需求而且只有这一点。随意使用它！

变量解释：$ imagewidth和$ imageheight自然是输入图像的原始像素大小。 $ crop_ratio_w是裁剪比率宽度，$ crop_ratio_h是裁剪比率高度。

因此，对于我的代码与您的代码：$ crop_ratio_w = $ thumb_width和$ crop_ratio_h = $ thumb_height

//do this if we can start cropping by width (there's enough space on height)
   if (($imagewidth * $crop_ratio_h / $crop_ratio_w) < $imageheight){
      //count new res
         $new_width = $imagewidth;
         $new_height = ($imagewidth * $crop_ratio_h / $crop_ratio_w);
      //count the height difference, so that new image is cropped in HEIGHT center
         $difference = ($imageheight - $new_height);
         $y_offset = ($difference / 2);
      //create new empty image
         $croppedImage = imagecreatetruecolor($new_width, $new_height);
      //copy wanted area to the new empty image
         imagecopy($croppedImage, $originalImage, 0, 0, 0, $y_offset, $new_width, $new_height);
   }
//else on previous condition -- do this if we have to start cropping by height (there's not enough space on height)
   else{
      //count new res
         $new_width = ($imageheight * $crop_ratio_w / $crop_ratio_h);
         $new_height = $imageheight;
      //count the height difference, so that new image is cropped in WIDTH center
         $difference = ($imagewidth - $new_width);
         $x_offset = ($difference / 2);
      //create new empty image
         $croppedImage = imagecreatetruecolor($new_width, $new_height);
      //copy wanted area to the new empty image
         imagecopy($croppedImage, $originalImage, 0, 0, $x_offset, 0, $new_width, $new_height);
   }

PHP裁剪高图像

2 个答案: