无法通过上传脚本保持透明度
Trouble keeping transparency with upload script
所以我不确定我做错了什么，我认为我已经完美地工作了，直到我上传了一个透明背景的 PNG，然后它以黑色背景保存。谁能指出我做错了什么？这是我的图片 class 和上传代码。我认为 'imagecreatefrompng' 部分可以保持透明度，但也许我错了或做错了？
图片Class
<?php
ini_set("memory_limit","50M");
function normal_resize_image($source, $destination, $image_type, $max_size, $image_width, $image_height, $quality){
if($image_width <= 0 || $image_height <= 0){return false;} //return false if nothing to resize
//do not resize if image is smaller than max size
if($image_width <= $max_size && $image_height <= $max_size){
if(save_image($source, $destination, $image_type, $quality)){
return true;
}
}
//Construct a proportional size of new image
$image_scale = min($max_size/$image_width, $max_size/$image_height);
$new_width = ceil($image_scale * $image_width);
$new_height = ceil($image_scale * $image_height);
$new_canvas = imagecreatetruecolor( $new_width, $new_height ); //Create a new true color image
imagealphablending($new_canvas,true);
//Copy and resize part of an image with resampling
if(imagecopyresampled($new_canvas, $source, 0, 0, 0, 0, $new_width, $new_height, $image_width, $image_height)){
save_image($new_canvas, $destination, $image_type, $quality); //save resized image
}
return true;
}
function thumb_resize_image($source, $destination, $image_type, $max_size, $image_width, $image_height, $quality){
if($image_width <= 0 || $image_height <= 0){return false;} //return false if nothing to resize
//do not resize if image is smaller than max size
if($image_width <= $max_size && $image_height <= $max_size){
if(save_image($source, $destination, $image_type, $quality)){
return true;
}
}
//Construct a proportional size of new image
$image_scale = min($max_size/$image_width, $max_size/$image_height);
$new_width = ceil($image_scale * $image_width);
$new_height = ceil($image_scale * $image_height);
$new_canvas = imagecreatetruecolor( $new_width, $new_height ); //Create a new true color image
imagealphablending($new_canvas,true);
//Copy and resize part of an image with resampling
if(imagecopyresampled($new_canvas, $source, 0, 0, 0, 0, $new_width, $new_height, $image_width, $image_height)){
save_image($new_canvas, $destination, $image_type, $quality); //save resized image
}
return true;
}
##### This function corps image to create exact square, no matter what its original size! ######
function crop_image_square($source, $destination, $image_type, $square_size, $image_width, $image_height, $quality){
if($image_width <= 0 || $image_height <= 0){return false;} //return false if nothing to resize
if( $image_width > $image_height )
{
$y_offset = 0;
$x_offset = ($image_width - $image_height) / 2;
$s_size = $image_width - ($x_offset * 2);
}else{
$x_offset = 0;
$y_offset = ($image_height - $image_width) / 2;
$s_size = $image_height - ($y_offset * 2);
}
$new_canvas = imagecreatetruecolor( $square_size, $square_size); //Create a new true color image
imagealphablending($new_canvas,true);
//Copy and resize part of an image with resampling
if(imagecopyresampled($new_canvas, $source, 0, 0, $x_offset, $y_offset, $square_size, $square_size, $s_size, $s_size)){
save_image($new_canvas, $destination, $image_type, $quality);
}
return true;
}
##### Saves image resource to file #####
function save_image($source, $destination, $image_type, $quality){
switch(strtolower($image_type)){//determine mime type
case 'image/png':
imagepng($source, $destination); return true; //save png file
break;
case 'image/gif':
imagegif($source, $destination); return true; //save gif file
break;
case 'image/jpeg': case 'image/pjpeg':
imagejpeg($source, $destination, $quality); return true; //save jpeg file
break;
default: return false;
}
}
?>
这是要上传的代码。
if(isset($_POST['addImages'])) {
$valid_formats = array("jpg", "jpeg", "png", "gif", "bmp", "JPG", "JPEG", "PNG", "GIF", "BMP");
$max_file_size = 50971520; //50mb
$path = "images/media/"; // Upload directory
$count = 0;
$thumb_square_size = 300; //Thumbnails will be cropped
$max_image_size = 1200; //Maximum image size (height and width)
$thumb_prefix = "_thumb"; //Normal thumb Prefix
$destination_folder = 'images/media/'; //upload directory ends with / (slash)
$jpeg_quality = 90; //jpeg quality
// Loop $_FILES to execute all files
foreach ($_FILES['files']['name'] as $foto => $name) {
if ($_FILES['files']['error'][$foto] == 4) {
continue; // Skip file if any error found
}
if ($_FILES['files']['error'][$foto] == 0) {
if ($_FILES['files']['size'][$foto] > $max_file_size) {
$message[] = "$name is too large!.";
continue; // Skip large files
}
elseif( ! in_array(pathinfo($name, PATHINFO_EXTENSION), $valid_formats) ){
$message[] = "$name is not a valid format";
continue; // Skip invalid file formats
}
else { // No error found!
$image_name = $name; //file name
$image_size = $_FILES['files']['size'][$foto]; //file size
$image_temp = $_FILES['files']['tmp_name'][$foto]; //file temp
$image_size_info = getimagesize($image_temp); //get image size
if($image_size_info){
$image_width = $image_size_info[0]; //image width
$image_height = $image_size_info[1]; //image height
$image_type = $image_size_info['mime']; //image type
} else {
die("Make sure image file is valid!");
}
//switch statement below checks allowed image type as well as creates new image from given file.
switch($image_type){
case 'image/png':
$image_res = imagecreatefrompng($image_temp);
imageAlphaBlending($image_res, true);
imageSaveAlpha($image_res, true);
break;
case 'image/gif':
$image_res = imagecreatefromgif($image_temp); break;
case 'image/jpeg': case 'image/pjpeg':
$image_res = imagecreatefromjpeg($image_temp); break;
default:
$image_res = false;
}
if($image_res){
//Get file extension and name to construct new file name
$image_info = pathinfo($image_name);
$image_extension = strtolower($image_info["extension"]); //image extension
$image_name_only = strtolower($image_info["filename"]);//file name only, no extension
$dateRec = date('d-M-Y-h-i-s');
//create a random name for new image (Eg: fileName_293749.jpg) ;
$new_file_name = $dateRec. '_' . rand(0, 9999999999);
//folder path to save resized images and thumbnails
$thumb_save_folder = $destination_folder . $new_file_name . $thumb_prefix . '.' . $image_extension ;
$image_save_folder = $destination_folder . $new_file_name. '.' . $image_extension;
//call normal_resize_image() function to proportionally resize image
if(normal_resize_image($image_res, $image_save_folder, $image_type, $max_image_size, $image_width, $image_height, $jpeg_quality)) {
//call crop_image_square() function to create square thumbnails
if(!thumb_resize_image($image_res, $thumb_save_folder, $image_type, $thumb_square_size, $image_width, $image_height, $jpeg_quality)) {
die('Error Creating thumbnail');
}
}
}
$post_img = $new_file_name.'.'.$image_extension;
$post_img_thumb = $new_file_name.$thumb_prefix.'.'.$image_extension;
$stmt = $mysqli->prepare('INSERT INTO media_images(image, image_thumb, members_id) VALUES (?,?,?)');
$stmt->bind_param('ssi', $post_img, $post_img_thumb, $members_id);
$stmt->execute();
$stmt->close();
$count++;
}
}
}
$MEMUS = memory_get_usage();
ob_start();
header("Location: media.php");
}
您必须使用 imagealphablending()。将 imagealphablending($new_canvas,true); 放在 imagecreatetruecolor 命令之后。
您在创建图像或图层时也需要使用 imagealphablending。因此，在您的上传中，您将在 imagecreatefromX 切换之后以及 imagecopyresampled 调用之后使用它。
You need to enable alpha and save the setting
case 'image/png':
$image_res = imagecreatefrompng($image_temp);
imageAlphaBlending($image_res, true);
imageSaveAlpha($image_res, true);
break;
您的问题已通过以下方式解决。
function resizeImage($source, $destination, $image_type, $max_size, $image_width, $image_height, $quality) {
//RETURN FALSE IF NOTHING TO RESIZE
if($image_width <= 0 || $image_height <= 0){return false;}
//CHECK IF SMALLER THAN THE MAX SIZES
if($image_width <= $max_size && $image_height <= $max_size) { //IF SMALLER THAN MAX SIZES
$new_width = $image_width;
$new_height = $image_height;
} else { //ELSE CONSTRUCT PROPORTIONAL SIZE OF NEW IMAGE
$image_scale = min($max_size/$image_width, $max_size/$image_height);
$new_width = ceil($image_scale * $image_width);
$new_height = ceil($image_scale * $image_height);
}
$new_canvas = imagecreatetruecolor($new_width, $new_height);
$black = imagecolorallocate($new_canvas, 0, 0, 0);
imagecolortransparent($new_canvas, $black);
imagealphablending($new_canvas,false);
imagesavealpha($new_canvas, true);
if(imagecopyresampled($new_canvas, $source, 0, 0, 0, 0, $new_width, $new_height, $image_width, $image_height)){
$this->save_image($new_canvas, $destination, $image_type, $quality);
}
return true;
}
//Resize Image Normal
function normal_resize_image($source, $destination, $image_type, $max_size, $image_width, $image_height, $quality) {
//RETURN FALSE IF NOTHING TO RESIZE
if($image_width <= 0 || $image_height <= 0){return false;}
//CHECK IF SMALLER THAN THE MAX SIZES
if($image_width <= $max_size && $image_height <= $max_size) { //IF SMALLER THAN MAX SIZES
$new_width = $image_width;
$new_height = $image_height;
} else { //ELSE CONSTRUCT PROPORTIONAL SIZE OF NEW IMAGE
$image_scale = min($max_size/$image_width, $max_size/$image_height);
$new_width = ceil($image_scale * $image_width);
$new_height = ceil($image_scale * $image_height);
}
$new_canvas = imagecreatetruecolor($new_width, $new_height);
$black = imagecolorallocate($new_canvas, 0, 0, 0);
imagecolortransparent($new_canvas, $black);
imagealphablending($new_canvas,false);
imagesavealpha($new_canvas, true);
if(imagecopyresampled($new_canvas, $source, 0, 0, 0, 0, $new_width, $new_height, $image_width, $image_height)){
$this->save_image($new_canvas, $destination, $image_type, $quality);
}
return true;
}
如果可行，请告诉我。可能需要为您做一些调整。
所以我不确定我做错了什么，我认为我已经完美地工作了，直到我上传了一个透明背景的 PNG，然后它以黑色背景保存。谁能指出我做错了什么？这是我的图片 class 和上传代码。我认为 'imagecreatefrompng' 部分可以保持透明度，但也许我错了或做错了？
图片Class
<?php
ini_set("memory_limit","50M");
function normal_resize_image($source, $destination, $image_type, $max_size, $image_width, $image_height, $quality){
if($image_width <= 0 || $image_height <= 0){return false;} //return false if nothing to resize
//do not resize if image is smaller than max size
if($image_width <= $max_size && $image_height <= $max_size){
if(save_image($source, $destination, $image_type, $quality)){
return true;
}
}
//Construct a proportional size of new image
$image_scale = min($max_size/$image_width, $max_size/$image_height);
$new_width = ceil($image_scale * $image_width);
$new_height = ceil($image_scale * $image_height);
$new_canvas = imagecreatetruecolor( $new_width, $new_height ); //Create a new true color image
imagealphablending($new_canvas,true);
//Copy and resize part of an image with resampling
if(imagecopyresampled($new_canvas, $source, 0, 0, 0, 0, $new_width, $new_height, $image_width, $image_height)){
save_image($new_canvas, $destination, $image_type, $quality); //save resized image
}
return true;
}
function thumb_resize_image($source, $destination, $image_type, $max_size, $image_width, $image_height, $quality){
if($image_width <= 0 || $image_height <= 0){return false;} //return false if nothing to resize
//do not resize if image is smaller than max size
if($image_width <= $max_size && $image_height <= $max_size){
if(save_image($source, $destination, $image_type, $quality)){
return true;
}
}
//Construct a proportional size of new image
$image_scale = min($max_size/$image_width, $max_size/$image_height);
$new_width = ceil($image_scale * $image_width);
$new_height = ceil($image_scale * $image_height);
$new_canvas = imagecreatetruecolor( $new_width, $new_height ); //Create a new true color image
imagealphablending($new_canvas,true);
//Copy and resize part of an image with resampling
if(imagecopyresampled($new_canvas, $source, 0, 0, 0, 0, $new_width, $new_height, $image_width, $image_height)){
save_image($new_canvas, $destination, $image_type, $quality); //save resized image
}
return true;
}
##### This function corps image to create exact square, no matter what its original size! ######
function crop_image_square($source, $destination, $image_type, $square_size, $image_width, $image_height, $quality){
if($image_width <= 0 || $image_height <= 0){return false;} //return false if nothing to resize
if( $image_width > $image_height )
{
$y_offset = 0;
$x_offset = ($image_width - $image_height) / 2;
$s_size = $image_width - ($x_offset * 2);
}else{
$x_offset = 0;
$y_offset = ($image_height - $image_width) / 2;
$s_size = $image_height - ($y_offset * 2);
}
$new_canvas = imagecreatetruecolor( $square_size, $square_size); //Create a new true color image
imagealphablending($new_canvas,true);
//Copy and resize part of an image with resampling
if(imagecopyresampled($new_canvas, $source, 0, 0, $x_offset, $y_offset, $square_size, $square_size, $s_size, $s_size)){
save_image($new_canvas, $destination, $image_type, $quality);
}
return true;
}
##### Saves image resource to file #####
function save_image($source, $destination, $image_type, $quality){
switch(strtolower($image_type)){//determine mime type
case 'image/png':
imagepng($source, $destination); return true; //save png file
break;
case 'image/gif':
imagegif($source, $destination); return true; //save gif file
break;
case 'image/jpeg': case 'image/pjpeg':
imagejpeg($source, $destination, $quality); return true; //save jpeg file
break;
default: return false;
}
}
?>
这是要上传的代码。
if(isset($_POST['addImages'])) {
$valid_formats = array("jpg", "jpeg", "png", "gif", "bmp", "JPG", "JPEG", "PNG", "GIF", "BMP");
$max_file_size = 50971520; //50mb
$path = "images/media/"; // Upload directory
$count = 0;
$thumb_square_size = 300; //Thumbnails will be cropped
$max_image_size = 1200; //Maximum image size (height and width)
$thumb_prefix = "_thumb"; //Normal thumb Prefix
$destination_folder = 'images/media/'; //upload directory ends with / (slash)
$jpeg_quality = 90; //jpeg quality
// Loop $_FILES to execute all files
foreach ($_FILES['files']['name'] as $foto => $name) {
if ($_FILES['files']['error'][$foto] == 4) {
continue; // Skip file if any error found
}
if ($_FILES['files']['error'][$foto] == 0) {
if ($_FILES['files']['size'][$foto] > $max_file_size) {
$message[] = "$name is too large!.";
continue; // Skip large files
}
elseif( ! in_array(pathinfo($name, PATHINFO_EXTENSION), $valid_formats) ){
$message[] = "$name is not a valid format";
continue; // Skip invalid file formats
}
else { // No error found!
$image_name = $name; //file name
$image_size = $_FILES['files']['size'][$foto]; //file size
$image_temp = $_FILES['files']['tmp_name'][$foto]; //file temp
$image_size_info = getimagesize($image_temp); //get image size
if($image_size_info){
$image_width = $image_size_info[0]; //image width
$image_height = $image_size_info[1]; //image height
$image_type = $image_size_info['mime']; //image type
} else {
die("Make sure image file is valid!");
}
//switch statement below checks allowed image type as well as creates new image from given file.
switch($image_type){
case 'image/png':
$image_res = imagecreatefrompng($image_temp);
imageAlphaBlending($image_res, true);
imageSaveAlpha($image_res, true);
break;
case 'image/gif':
$image_res = imagecreatefromgif($image_temp); break;
case 'image/jpeg': case 'image/pjpeg':
$image_res = imagecreatefromjpeg($image_temp); break;
default:
$image_res = false;
}
if($image_res){
//Get file extension and name to construct new file name
$image_info = pathinfo($image_name);
$image_extension = strtolower($image_info["extension"]); //image extension
$image_name_only = strtolower($image_info["filename"]);//file name only, no extension
$dateRec = date('d-M-Y-h-i-s');
//create a random name for new image (Eg: fileName_293749.jpg) ;
$new_file_name = $dateRec. '_' . rand(0, 9999999999);
//folder path to save resized images and thumbnails
$thumb_save_folder = $destination_folder . $new_file_name . $thumb_prefix . '.' . $image_extension ;
$image_save_folder = $destination_folder . $new_file_name. '.' . $image_extension;
//call normal_resize_image() function to proportionally resize image
if(normal_resize_image($image_res, $image_save_folder, $image_type, $max_image_size, $image_width, $image_height, $jpeg_quality)) {
//call crop_image_square() function to create square thumbnails
if(!thumb_resize_image($image_res, $thumb_save_folder, $image_type, $thumb_square_size, $image_width, $image_height, $jpeg_quality)) {
die('Error Creating thumbnail');
}
}
}
$post_img = $new_file_name.'.'.$image_extension;
$post_img_thumb = $new_file_name.$thumb_prefix.'.'.$image_extension;
$stmt = $mysqli->prepare('INSERT INTO media_images(image, image_thumb, members_id) VALUES (?,?,?)');
$stmt->bind_param('ssi', $post_img, $post_img_thumb, $members_id);
$stmt->execute();
$stmt->close();
$count++;
}
}
}
$MEMUS = memory_get_usage();
ob_start();
header("Location: media.php");
}
您必须使用 imagealphablending()。将 imagealphablending($new_canvas,true); 放在 imagecreatetruecolor 命令之后。
您在创建图像或图层时也需要使用 imagealphablending。因此，在您的上传中，您将在 imagecreatefromX 切换之后以及 imagecopyresampled 调用之后使用它。
You need to enable alpha and save the setting
case 'image/png':
$image_res = imagecreatefrompng($image_temp);
imageAlphaBlending($image_res, true);
imageSaveAlpha($image_res, true);
break;
您的问题已通过以下方式解决。
function resizeImage($source, $destination, $image_type, $max_size, $image_width, $image_height, $quality) {
//RETURN FALSE IF NOTHING TO RESIZE
if($image_width <= 0 || $image_height <= 0){return false;}
//CHECK IF SMALLER THAN THE MAX SIZES
if($image_width <= $max_size && $image_height <= $max_size) { //IF SMALLER THAN MAX SIZES
$new_width = $image_width;
$new_height = $image_height;
} else { //ELSE CONSTRUCT PROPORTIONAL SIZE OF NEW IMAGE
$image_scale = min($max_size/$image_width, $max_size/$image_height);
$new_width = ceil($image_scale * $image_width);
$new_height = ceil($image_scale * $image_height);
}
$new_canvas = imagecreatetruecolor($new_width, $new_height);
$black = imagecolorallocate($new_canvas, 0, 0, 0);
imagecolortransparent($new_canvas, $black);
imagealphablending($new_canvas,false);
imagesavealpha($new_canvas, true);
if(imagecopyresampled($new_canvas, $source, 0, 0, 0, 0, $new_width, $new_height, $image_width, $image_height)){
$this->save_image($new_canvas, $destination, $image_type, $quality);
}
return true;
}
//Resize Image Normal
function normal_resize_image($source, $destination, $image_type, $max_size, $image_width, $image_height, $quality) {
//RETURN FALSE IF NOTHING TO RESIZE
if($image_width <= 0 || $image_height <= 0){return false;}
//CHECK IF SMALLER THAN THE MAX SIZES
if($image_width <= $max_size && $image_height <= $max_size) { //IF SMALLER THAN MAX SIZES
$new_width = $image_width;
$new_height = $image_height;
} else { //ELSE CONSTRUCT PROPORTIONAL SIZE OF NEW IMAGE
$image_scale = min($max_size/$image_width, $max_size/$image_height);
$new_width = ceil($image_scale * $image_width);
$new_height = ceil($image_scale * $image_height);
}
$new_canvas = imagecreatetruecolor($new_width, $new_height);
$black = imagecolorallocate($new_canvas, 0, 0, 0);
imagecolortransparent($new_canvas, $black);
imagealphablending($new_canvas,false);
imagesavealpha($new_canvas, true);
if(imagecopyresampled($new_canvas, $source, 0, 0, 0, 0, $new_width, $new_height, $image_width, $image_height)){
$this->save_image($new_canvas, $destination, $image_type, $quality);
}
return true;
}
如果可行，请告诉我。可能需要为您做一些调整。