我想写一些PHP代码，自动调整通过表单上传到147x147px的任何图像，但我不知道如何去做（我是一个相对的PHP新手）。
到目前为止，我已成功上传图片，识别文件类型并清理名称，但我想将调整大小功能添加到代码中。例如，我有一个2.3MB的测试图像，尺寸为1331x1331，我希望代码可以缩小尺寸，我猜测它也会大大压缩图像的文件大小。
到目前为止，我有以下内容：
if ($_FILES) {
//Put file properties into variables
$file_name = $_FILES['profile-image']['name'];
$file_size = $_FILES['profile-image']['size'];
$file_tmp_name = $_FILES['profile-image']['tmp_name'];
//Determine filetype
switch ($_FILES['profile-image']['type']) {
case 'image/jpeg': $ext = "jpg"; break;
case 'image/png': $ext = "png"; break;
default: $ext = ''; break;
}
if ($ext) {
//Check filesize
if ($file_size < 500000) {
//Process file - clean up filename and move to safe location
$n = "$file_name";
$n = ereg_replace("[^A-Za-z0-9.]", "", $n);
$n = strtolower($n);
$n = "avatars/$n";
move_uploaded_file($file_tmp_name, $n);
} else {
$bad_message = "Please ensure your chosen file is less than 5MB.";
}
} else {
$bad_message = "Please ensure your image is of filetype .jpg or.png.";
}
}
$query = "INSERT INTO users (image) VALUES ('$n')";
mysql_query($query) or die("Insert failed. " . mysql_error() . "<br />" . $query);
您需要使用PHP的ImageMagick或GD函数来处理图像。
以GD为例，它就像......一样简单
function resize_image($file, $w, $h, $crop=FALSE) {
list($width, $height) = getimagesize($file);
$r = $width / $height;
if ($crop) {
if ($width > $height) {
$width = ceil($width-($width*abs($r-$w/$h)));
} else {
$height = ceil($height-($height*abs($r-$w/$h)));
}
$newwidth = $w;
$newheight = $h;
} else {
if ($w/$h > $r) {
$newwidth = $h*$r;
$newheight = $h;
} else {
$newheight = $w/$r;
$newwidth = $w;
}
}
$src = imagecreatefromjpeg($file);
$dst = imagecreatetruecolor($newwidth, $newheight);
imagecopyresampled($dst, $src, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
return $dst;
}
你可以调用这个函数，就像这样......
$img = resize_image(‘/path/to/some/image.jpg’, 200, 200);
从个人经验来看，GD的图像重新采样确实大大减少了文件大小，特别是在重新采样原始数码相机图像时。
我建议您使用piio.co，一旦您将图像上传到存储空间，只需使用<img />标签中的原始图像网址，图书馆就会自动为您调整大小。
您的图片代码如下所示：
<img data-piio="/image/gallery/p/image1.jpg" />
然后，一旦初始化Piio的脚本，它将自动调整图像大小并从CDN服务。
这是docs的链接
如果你想手动完成，那么我建议你使用原生的php函数，这将使用GD库。例如，如果要调整JPEG大小，可以从以下开始：
list($width, $height) = getimagesize($filepath);
$original = imagecreatefromjpeg($filepath);
$thumb = imagecreatetruecolor($new_width, $new_height);
imagecopyresized($thumb, $original, 0, 0, 0, 0, $new_width, $new_height, $width, $height);
要直接输出图像：
imagejpeg($thumb);
要将图像保存到文件：
imagejpeg($thumb, 'filepath/image.jpg');
我找到了一种完成这项工作的数学方法
Github repo - https://github.com/gayanSandamal/easy-php-image-resizer
实例 - https://plugins.nayague.com/easy-php-image-resizer/
<?php
//path for the image
$source_url = '2018-04-01-1522613288.PNG';
//separate the file name and the extention
$source_url_parts = pathinfo($source_url);
$filename = $source_url_parts['filename'];
$extension = $source_url_parts['extension'];
//define the quality from 1 to 100
$quality = 10;
//detect the width and the height of original image
list($width, $height) = getimagesize($source_url);
$width;
$height;
//define any width that you want as the output. mine is 200px.
$after_width = 200;
//resize only when the original image is larger than expected with.
//this helps you to avoid from unwanted resizing.
if ($width > $after_width) {
//get the reduced width
$reduced_width = ($width - $after_width);
//now convert the reduced width to a percentage and round it to 2 decimal places
$reduced_radio = round(($reduced_width / $width) * 100, 2);
//ALL GOOD! let's reduce the same percentage from the height and round it to 2 decimal places
$reduced_height = round(($height / 100) * $reduced_radio, 2);
//reduce the calculated height from the original height
$after_height = $height - $reduced_height;
//Now detect the file extension
//if the file extension is 'jpg', 'jpeg', 'JPG' or 'JPEG'
if ($extension == 'jpg' || $extension == 'jpeg' || $extension == 'JPG' || $extension == 'JPEG') {
//then return the image as a jpeg image for the next step
$img = imagecreatefromjpeg($source_url);
} elseif ($extension == 'png' || $extension == 'PNG') {
//then return the image as a png image for the next step
$img = imagecreatefrompng($source_url);
} else {
//show an error message if the file extension is not available
echo 'image extension is not supporting';
}
//HERE YOU GO :)
//Let's do the resize thing
//imagescale([returned image], [width of the resized image], [height of the resized image], [quality of the resized image]);
$imgResized = imagescale($img, $after_width, $after_height, $quality);
//now save the resized image with a suffix called "-resized" and with its extension.
imagejpeg($imgResized, $filename . '-resized.'.$extension);
//Finally frees any memory associated with image
//**NOTE THAT THIS WONT DELETE THE IMAGE
imagedestroy($img);
imagedestroy($imgResized);
}
?>
This resource也值得考虑 - 一些使用GD的非常整洁的代码。但是，我修改了他们的最终代码片段以创建符合OP要求的此功能...
function store_uploaded_image($html_element_name, $new_img_width, $new_img_height) {
$target_dir = "your-uploaded-images-folder/";
$target_file = $target_dir . basename($_FILES[$html_element_name]["name"]);
$image = new SimpleImage();
$image->load($_FILES[$html_element_name]['tmp_name']);
$image->resize($new_img_width, $new_img_height);
$image->save($target_file);
return $target_file; //return name of saved file in case you want to store it in you database or show confirmation message to user
}
您还需要包含此PHP文件...
<?php
/*
* File: SimpleImage.php
* Author: Simon Jarvis
* Copyright: 2006 Simon Jarvis
* Date: 08/11/06
* Link: http://www.white-hat-web-design.co.uk/blog/resizing-images-with-php/
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details:
* http://www.gnu.org/licenses/gpl.html
*
*/
class SimpleImage {
var $image;
var $image_type;
function load($filename) {
$image_info = getimagesize($filename);
$this->image_type = $image_info[2];
if( $this->image_type == IMAGETYPE_JPEG ) {
$this->image = imagecreatefromjpeg($filename);
} elseif( $this->image_type == IMAGETYPE_GIF ) {
$this->image = imagecreatefromgif($filename);
} elseif( $this->image_type == IMAGETYPE_PNG ) {
$this->image = imagecreatefrompng($filename);
}
}
function save($filename, $image_type=IMAGETYPE_JPEG, $compression=75, $permissions=null) {
if( $image_type == IMAGETYPE_JPEG ) {
imagejpeg($this->image,$filename,$compression);
} elseif( $image_type == IMAGETYPE_GIF ) {
imagegif($this->image,$filename);
} elseif( $image_type == IMAGETYPE_PNG ) {
imagepng($this->image,$filename);
}
if( $permissions != null) {
chmod($filename,$permissions);
}
}
function output($image_type=IMAGETYPE_JPEG) {
if( $image_type == IMAGETYPE_JPEG ) {
imagejpeg($this->image);
} elseif( $image_type == IMAGETYPE_GIF ) {
imagegif($this->image);
} elseif( $image_type == IMAGETYPE_PNG ) {
imagepng($this->image);
}
}
function getWidth() {
return imagesx($this->image);
}
function getHeight() {
return imagesy($this->image);
}
function resizeToHeight($height) {
$ratio = $height / $this->getHeight();
$width = $this->getWidth() * $ratio;
$this->resize($width,$height);
}
function resizeToWidth($width) {
$ratio = $width / $this->getWidth();
$height = $this->getheight() * $ratio;
$this->resize($width,$height);
}
function scale($scale) {
$width = $this->getWidth() * $scale/100;
$height = $this->getheight() * $scale/100;
$this->resize($width,$height);
}
function resize($width,$height) {
$new_image = imagecreatetruecolor($width, $height);
imagecopyresampled($new_image, $this->image, 0, 0, 0, 0, $width, $height, $this->getWidth(), $this->getHeight());
$this->image = $new_image;
}
}
?>
如果您不关心纵横比（即您想要将图像强制为特定尺寸），这里有一个简化的答案
// for jpg
function resize_imagejpg($file, $w, $h) {
list($width, $height) = getimagesize($file);
$src = imagecreatefromjpeg($file);
$dst = imagecreatetruecolor($w, $h);
imagecopyresampled($dst, $src, 0, 0, 0, 0, $w, $h, $width, $height);
return $dst;
}
// for png
function resize_imagepng($file, $w, $h) {
list($width, $height) = getimagesize($file);
$src = imagecreatefrompng($file);
$dst = imagecreatetruecolor($w, $h);
imagecopyresampled($dst, $src, 0, 0, 0, 0, $w, $h, $width, $height);
return $dst;
}
// for gif
function resize_imagegif($file, $w, $h) {
list($width, $height) = getimagesize($file);
$src = imagecreatefromgif($file);
$dst = imagecreatetruecolor($w, $h);
imagecopyresampled($dst, $src, 0, 0, 0, 0, $w, $h, $width, $height);
return $dst;
}
现在让我们处理上传部分。第一步，将文件上传到所需目录。然后根据文件类型（jpg，png或gif）调用上述函数之一，并传递上传文件的绝对路径，如下所示：
// jpg change the dimension 750, 450 to your desired values
$img = resize_imagejpg('path/image.jpg', 750, 450);
返回值$img是一个资源对象。我们可以保存到新位置或覆盖原始内容，如下所示：
// again for jpg
imagejpeg($img, 'path/newimage.jpg');
希望这有助于某人。有关调整Imagick::resizeImage和imagejpeg()大小的更多信息，请查看这些链接
我希望能为你效劳。
/**
* Image re-size
* @param int $width
* @param int $height
*/
function ImageResize($width, $height, $img_name)
{
/* Get original file size */
list($w, $h) = getimagesize($_FILES['logo_image']['tmp_name']);
/*$ratio = $w / $h;
$size = $width;
$width = $height = min($size, max($w, $h));
if ($ratio < 1) {
$width = $height * $ratio;
} else {
$height = $width / $ratio;
}*/
/* Calculate new image size */
$ratio = max($width/$w, $height/$h);
$h = ceil($height / $ratio);
$x = ($w - $width / $ratio) / 2;
$w = ceil($width / $ratio);
/* set new file name */
$path = $img_name;
/* Save image */
if($_FILES['logo_image']['type']=='image/jpeg')
{
/* Get binary data from image */
$imgString = file_get_contents($_FILES['logo_image']['tmp_name']);
/* create image from string */
$image = imagecreatefromstring($imgString);
$tmp = imagecreatetruecolor($width, $height);
imagecopyresampled($tmp, $image, 0, 0, $x, 0, $width, $height, $w, $h);
imagejpeg($tmp, $path, 100);
}
else if($_FILES['logo_image']['type']=='image/png')
{
$image = imagecreatefrompng($_FILES['logo_image']['tmp_name']);
$tmp = imagecreatetruecolor($width,$height);
imagealphablending($tmp, false);
imagesavealpha($tmp, true);
imagecopyresampled($tmp, $image,0,0,$x,0,$width,$height,$w, $h);
imagepng($tmp, $path, 0);
}
else if($_FILES['logo_image']['type']=='image/gif')
{
$image = imagecreatefromgif($_FILES['logo_image']['tmp_name']);
$tmp = imagecreatetruecolor($width,$height);
$transparent = imagecolorallocatealpha($tmp, 0, 0, 0, 127);
imagefill($tmp, 0, 0, $transparent);
imagealphablending($tmp, true);
imagecopyresampled($tmp, $image,0,0,0,0,$width,$height,$w, $h);
imagegif($tmp, $path);
}
else
{
return false;
}
return true;
imagedestroy($image);
imagedestroy($tmp);
}
只需简单地使用php函数：给定为
// Read the image
$img = imagecreatefromjpeg("source_of_img.jpg");
// Now resize the image width = 200 and height = 200
$imgresize = imagescale($img, 200, 200);
更新：现在编写webp和bmp调整大小，并保持透明背景！ （重要提示：这次不适合动画（webp或gif）调整大小，只需调整第一帧的大小并从中创建一个非动画图像！我将在接下来的几周（当我有时间）更新此答案，并且最终结果将是一个简单的类，具有一个公共和一些私有函数，但也没有任何第三方库或框架特定依赖。）
我创建了这个关于https://www.techfry.com/php-tutorial的php 7.2项目，与GD2，（所以没有第三方库）和非常类似于Nico Bistolfi的答案，但是使用了所有五个基本图像mimetype（png，jpeg，webp，bmp和gif） ），创建一个新的已调整大小的文件，而不修改原始文件，并将所有内容放在一个（和安全）功能中并准备使用（复制并粘贴到您的项目中）。 （新文件将是png，我在大多数情况下使用png，因为质量，但你可以轻松地更改这部分，使用注释或从他们建立关于$ type的逻辑）：
function createResizedImage(
string $imagePath = '',
string $newPath = '',
int $newWidth = 0,
int $newHeight = 0
) : bool
{
if (
$newPath === '' or
file_exists($imagePath) === false
) {
return false;
}
if (
in_array(
(
$type = exif_imagetype($imagePath)
),
[
IMAGETYPE_JPEG,
IMAGETYPE_PNG,
IMAGETYPE_GIF,
IMAGETYPE_BMP,
IMAGETYPE_WEBP
]
) === false
) {
return false;
}
list($width, $height) = getimagesize($imagePath);
if (
!(
$image = $type === IMAGETYPE_JPEG ? imagecreatefromjpeg($imagePath) : (
$type === IMAGETYPE_PNG ? imagecreatefrompng($imagePath) : (
$type === IMAGETYPE_BMP ? imagecreatefrombmp($imagePath) : (
$type === IMAGETYPE_WEBP ? imagecreatefromwebp($imagePath) : (
$type === IMAGETYPE_GIF ? imagecreatefromgif($imagePath) : false
)
)
)
)
)
) {
return false;
}
$newImage = imagecreatetruecolor($newWidth, $newHeight);
//TRANSPARENT BACKGROUND
$color = imagecolorallocatealpha($newImage, 0, 0, 0, 127); //fill transparent back
imagefill($newImage, 0, 0, $color);
imagesavealpha($newImage, true);
//ROUTINE
imagecopyresampled($newImage, $image, 0, 0, 0, 0, $newWidth, $newHeight, $width, $height);
imagepng($newImage, $newPath);
#imagejpeg($newImage, $newPath);
#imagegif($newImage, $newPath);
return true;
}
ZF蛋糕：
<?php
class FkuController extends Zend_Controller_Action {
var $image;
var $image_type;
public function store_uploaded_image($html_element_name, $new_img_width, $new_img_height) {
$target_dir = APPLICATION_PATH . "/../public/1/";
$target_file = $target_dir . basename($_FILES[$html_element_name]["name"]);
//$image = new SimpleImage();
$this->load($_FILES[$html_element_name]['tmp_name']);
$this->resize($new_img_width, $new_img_height);
$this->save($target_file);
return $target_file;
//return name of saved file in case you want to store it in you database or show confirmation message to user
public function load($filename) {
$image_info = getimagesize($filename);
$this->image_type = $image_info[2];
if( $this->image_type == IMAGETYPE_JPEG ) {
$this->image = imagecreatefromjpeg($filename);
} elseif( $this->image_type == IMAGETYPE_GIF ) {
$this->image = imagecreatefromgif($filename);
} elseif( $this->image_type == IMAGETYPE_PNG ) {
$this->image = imagecreatefrompng($filename);
}
}
public function save($filename, $image_type=IMAGETYPE_JPEG, $compression=75, $permissions=null) {
if( $image_type == IMAGETYPE_JPEG ) {
imagejpeg($this->image,$filename,$compression);
} elseif( $image_type == IMAGETYPE_GIF ) {
imagegif($this->image,$filename);
} elseif( $image_type == IMAGETYPE_PNG ) {
imagepng($this->image,$filename);
}
if( $permissions != null) {
chmod($filename,$permissions);
}
}
public function output($image_type=IMAGETYPE_JPEG) {
if( $image_type == IMAGETYPE_JPEG ) {
imagejpeg($this->image);
} elseif( $image_type == IMAGETYPE_GIF ) {
imagegif($this->image);
} elseif( $image_type == IMAGETYPE_PNG ) {
imagepng($this->image);
}
}
public function getWidth() {
return imagesx($this->image);
}
public function getHeight() {
return imagesy($this->image);
}
public function resizeToHeight($height) {
$ratio = $height / $this->getHeight();
$width = $this->getWidth() * $ratio;
$this->resize($width,$height);
}
public function resizeToWidth($width) {
$ratio = $width / $this->getWidth();
$height = $this->getheight() * $ratio;
$this->resize($width,$height);
}
public function scale($scale) {
$width = $this->getWidth() * $scale/100;
$height = $this->getheight() * $scale/100;
$this->resize($width,$height);
}
public function resize($width,$height) {
$new_image = imagecreatetruecolor($width, $height);
imagecopyresampled($new_image, $this->image, 0, 0, 0, 0, $width, $height, $this->getWidth(), $this->getHeight());
$this->image = $new_image;
}
public function savepicAction() {
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);
$this->_helper->layout()->disableLayout();
$this->_helper->viewRenderer->setNoRender();
$this->_response->setHeader('Access-Control-Allow-Origin', '*');
$this->db = Application_Model_Db::db_load();
$ouser = $_POST['ousername'];
$fdata = 'empty';
if (isset($_FILES['picture']) && $_FILES['picture']['size'] > 0) {
$file_size = $_FILES['picture']['size'];
$tmpName = $_FILES['picture']['tmp_name'];
//Determine filetype
switch ($_FILES['picture']['type']) {
case 'image/jpeg': $ext = "jpg"; break;
case 'image/png': $ext = "png"; break;
case 'image/jpg': $ext = "jpg"; break;
case 'image/bmp': $ext = "bmp"; break;
case 'image/gif': $ext = "gif"; break;
default: $ext = ''; break;
}
if($ext) {
//if($file_size<400000) {
$img = $this->store_uploaded_image('picture', 90,82);
//$fp = fopen($tmpName, 'r');
$fp = fopen($img, 'r');
$fdata = fread($fp, filesize($tmpName));
$fdata = base64_encode($fdata);
fclose($fp);
//}
}
}
if($fdata=='empty'){
}
else {
$this->db->update('users',
array(
'picture' => $fdata,
),
array('username=?' => $ouser ));
}
}
您可以尝试使用TinyPNG PHP库。使用此库，您的图像会在调整大小过程中自动优化。您只需安装库并从https://tinypng.com/developers获取API密钥即可。要安装库，请运行以下命令。
composer require tinify/tinify
之后，您的代码如下。
require_once("vendor/autoload.php");
\Tinify\setKey("YOUR_API_KEY");
$source = \Tinify\fromFile("large.jpg"); //image to be resize
$resized = $source->resize(array(
"method" => "fit",
"width" => 150,
"height" => 100
));
$resized->toFile("thumbnail.jpg"); //resized image
我有一个关于同一主题http://artisansweb.net/resize-image-php-using-tinypng的博客
我创建了一个易于使用的库来调整图像大小。它可以找到here on Github。
如何使用库的示例：
// Include PHP Image Magician library
require_once('php_image_magician.php');
// Open JPG image
$magicianObj = new imageLib('racecar.jpg');
// Resize to best fit then crop (check out the other options)
$magicianObj -> resizeImage(100, 200, 'crop');
// Save resized image as a PNG (or jpg, bmp, etc)
$magicianObj -> saveImage('racecar_small.png');
如果您需要，其他功能包括：