Answer 1

Answer 2

尝试此功能....

<?php
function CropImg($img_dst, $img_src, $dst_width = 300, $dst_height = 180){
$ext = pathinfo($img_src, PATHINFO_EXTENSION);
if($ext != 'jpg' and $ext != 'jpeg'){
    $image = imagecreatefrompng($img_src);

}else{
    $image = imagecreatefromjpeg($img_src);
}
$filename = $img_dst;

$thumb_width = $dst_width;
$thumb_height = $dst_height;

$width = imagesx($image);
$height = imagesy($image);

$original_aspect = $width / $height;
$thumb_aspect = $thumb_width / $thumb_height;

if ( $original_aspect >= $thumb_aspect )
{
   // 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);
}

$thumb = imagecreatetruecolor( $thumb_width, $thumb_height );

if($ext == 'png'){
    imagealphablending($thumb, false);
    $white = imagecolorallocatealpha($thumb, 0, 0, 0, 127);    //FOR WHITE BACKGROUND
    imagefilledrectangle($thumb,0,0,$thumb_width,$thumb_height,$white);
    imagesavealpha($thumb, true);
}

// Resize and crop
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, $height);
if($ext == 'png'){
    imagepng($thumb, $filename);
}else{
    imagejpeg($thumb, $filename, 80);
}
return true;
}

CropImg("photo.png", "result.png", 300, 180);
?>