PHP-肖像图像在压缩后进行旋转

Question

我使用这个脚本来压缩上传的照片。照片是通过move_uploaded_file()上传的，然后我调用这个函数。但当我尝试压缩直接从相机拍摄的人像照片时(点击页面上的上传按钮，选择"拍照"选项，然后开始上传(，它总是向左旋转90度。

我试着找出问题出在哪里，但我的想法清单现在是空的，我就是想不出来。有什么想法吗？问题出在哪里？

(横向图像上传良好，不会旋转。(

function image_resize($file, $string = null, $width = 0, $height = 0, $proportional = true, $output = 'file', $delete_original = true, $quality = 100, $grayscale = false) {
if ($height <= 0 && $width <= 0) return false;
if ($file === null && $string === null) return false;
$info = $file !== null ? getimagesize($file) : getimagesizefromstring($string);
$image = '';
$final_width = 0;
$final_height = 0;
list($width_old, $height_old) = $info;
$cropHeight = $cropWidth = 0;
if ($proportional) {
if ($width  == 0) $factor = $height/$height_old;
elseif ($height == 0) $factor = $width/$width_old;
else $factor = min($width / $width_old, $height / $height_old);
$final_width  = round($width_old * $factor);
$final_height = round($height_old * $factor);
} else {
$final_width = ($width <= 0 ? $width_old : $width);
$final_height = ($height <= 0 ? $height_old : $height);
$widthX = $width_old / $width;
$heightX = $height_old / $height;
$x = min($widthX, $heightX);
$cropWidth = ($width_old - $width * $x) / 2;
$cropHeight = ($height_old - $height * $x) / 2;
}
// if the image is smaller than max. width/height, just keep it as is
if ($width_old < $width && $height_old < $height) {
$cropHeight = $cropWidth = 0;
$final_width = $width_old;
$final_height = $height_old;
}
switch($info[2]) {
case IMAGETYPE_JPEG:
$file !== null ? $image = imagecreatefromjpeg($file) : $image = imagecreatefromstring($string);
break;
case IMAGETYPE_GIF:
$file !== null ? $image = imagecreatefromgif($file) : $image = imagecreatefromstring($string);
break;
case IMAGETYPE_PNG:
$file !== null ? $image = imagecreatefrompng($file) : $image = imagecreatefromstring($string);
break;
default:
return false;
break;
}
// grayscale image
if ($grayscale) {
imagefilter($image, IMG_FILTER_GRAYSCALE);
}
$image_resized = imagecreatetruecolor($final_width, $final_height);
if (($info[2] == IMAGETYPE_GIF) || ($info[2] == IMAGETYPE_PNG)) {
$transparency = imagecolortransparent($image);
$palletsize = imagecolorstotal($image);
if ($transparency >= 0 && $transparency < $palletsize) {
$transparent_color = imagecolorsforindex($image, $transparency);
$transparency = imagecolorallocate($image_resized, $transparent_color['red'], $transparent_color['green'], $transparent_color['blue']);
imagefill($image_resized, 0, 0, $transparency);
imagecolortransparent($image_resized, $transparency);
} elseif ($info[2] == IMAGETYPE_PNG) {
imagealphablending($image_resized, false);
$color = imagecolorallocatealpha($image_resized, 0, 0, 0, 127);
imagefill($image_resized, 0, 0, $color);
imagesavealpha($image_resized, true);
}
}
imagecopyresampled($image_resized, $image, 0, 0, $cropWidth, $cropHeight, $final_width, $final_height, $width_old - 2 * $cropWidth, $height_old - 2 * $cropHeight);
// delete original image, if set
if ($delete_original) {
@unlink($file);
}
switch(strtolower($output)) {
case 'browser':
$mime = image_type_to_mime_type($info[2]);
header("Content-type: " . $mime);
$output = NULL;
break;
case 'file':
$output = $file;
break;
case 'return':
return $image_resized;
break;
default:
break;
}
// saving new image
switch($info[2]) {
case IMAGETYPE_GIF:
imagegif($image_resized, $output);
break;
case IMAGETYPE_JPEG:
imagejpeg($image_resized, $output, $quality);
break;
case IMAGETYPE_PNG:
$quality = 9 - (int)((0.9 * $quality) / 10.0);
imagepng($image_resized, $output, $quality);
break;
default:
return false;
}
return true;
}

Answer 1

感谢Ken的Lee想法，我尝试检查图像方向，如果是orientation > 1，我将通过下面的函数旋转它。

请注意，在上传和使用照片进行其他操作之前，您必须根据exif数据保存方向。当我保存并压缩它时，它丢失了所有exif信息，方向为1。

即使在压缩照片后，当创建了全新的图像时，如何保持exif数据有什么变化吗？

// 1) save orientation before upload
if (getimagesize($file['tmp_name'])['mime'] === 'image/jpeg') {
$exif = exif_read_data($file['tmp_name']);
if (!empty($exif['Orientation'])) {
$this->file_orientation = $exif['Orientation'];
}
}
// 2) upload and compress your photo
// ... 
// $output = '/path/to/compressed/photo.jpg';
// 3) check orientation of original photo and rotate the new-compressed one
if ($this->file_orientation > 1) {
$image = imagecreatefromjpeg($output);
if (in_array($orientation, [3, 4])) {
$image = imagerotate($image, 180, 0);
}
if (in_array($orientation, [5, 6])) {
$image = imagerotate($image, -90, 0);
}
if (in_array($orientation, [7, 8])) {
$image = imagerotate($image, 90, 0);
}
if (in_array($orientation, [2, 5, 7, 4])) {
imageflip($image, IMG_FLIP_HORIZONTAL);
}
imagejpeg($image, $output, $quality);
}