问题
I\'m wanting to write some PHP code which automatically resizes any image uploaded via a form to 147x147px, but I have no idea how to go about it (I\'m a relative PHP novice).
So far, I\'ve got images uploading successfully, filetypes being recognised and names cleaned up, but I\'d like to add the resize functionality into the code. For example, I\'ve got a test image which is 2.3MB, and 1331x1331 in dimension, and I\'d like the code to size it down, which I\'m guessing will dramatically compress the filesize of the image, too.
So far, I\'ve got the following:
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 />\" . $query);
回答1:
You need to use either PHP's ImageMagick or GD functions to work with images.
With GD, for example, it's as simple as...
function resize_image($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;
}
And you could call this function, like so...
$img = resize_image(‘/path/to/some/image.jpg’, 200, 200);
From personal experience, GD's image resampling does dramatically reduce file size too, especially when resampling raw digital camera images.
回答2:
This resource is also worth considering - some very tidy code that uses GD. However, I modified their final code snippet to create this function which meets the OPs requirements...
function store_uploaded_image($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
}
You will also need to include this PHP file...
<?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 = $new_image;
}
}
?>
回答3:
If you dont care about the aspect ration (i.e you want to force the image to a particular dimension), here is a simplified answer
// for jpg
function resize_imagejpg($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;
}
Now let's handle the upload part. First step, upload the file to your desired directory. Then called one of the above functions based on file type (jpg, png or gif) and pass the absolute path of your uploaded file as below:
// jpg change the dimension 750, 450 to your desired values
$img = resize_imagejpg('path/image.jpg', 750, 450);
The return value $img is a resource object. We can save to a new location or override the original as below:
// again for jpg
imagejpeg($img, 'path/newimage.jpg');
Hope this helps someone. Check these links for more on resizing Imagick::resizeImage and imagejpeg()
回答4:
Just simply use php function: given as
// Read the image
$img = imagecreatefromjpeg("source_of_img.jpg");
// Now resize the image width = 200 and height = 200
$imgresize = imagescale($img, 200, 200);
回答5:
I hope is will work for you.
/**
* 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);
}
回答6:
(IMPORTANT: In the case of animation (animated webp or gif) resizing, the result will be a not animated, but resized image from the first frame! (The original animation remains intact...)
I created this to my php 7.2 project (example imagebmp sure (PHP 7 >= 7.2.0) :php/manual/function.imagebmp) about techfry.com/php-tutorial, with GD2, (so nothing 3rd party library) and very similar to the answer of Nico Bistolfi, but works with the all five basic image mimetype (png, jpeg, webp, bmp and gif), creating a new resized file, without modifying the original one, and the all stuff in one function and ready to use (copy and paste to your project). (You can set the extension of the new file with the fifth parameter, or just leave it, if you want keep the orignal):
function createResizedImage(
string $imagePath = '',
string $newPath = '',
int $newWidth = 0,
int $newHeight = 0,
string $outExt = 'DEFAULT'
) : ?string
{
if (
$newPath === '' or
file_exists($imagePath) === false
) {
return null;
}
if (
in_array(
(
$type = exif_imagetype($imagePath)
),
[IMAGETYPE_JPEG, IMAGETYPE_PNG, IMAGETYPE_GIF, IMAGETYPE_BMP, IMAGETYPE_WEBP]
) === false
) {
return null;
}
list($width, $height) = getimagesize($imagePath);
$outBool = in_array($outExt, ['jpg', 'jpeg', 'png', 'gif', 'bmp', 'webp']);
switch (true)
{
case $type === IMAGETYPE_JPEG:
$image = imagecreatefromjpeg($imagePath);
if ($outBool === false) $outExt = 'jpg';
break;
case $type === IMAGETYPE_PNG:
$image = imagecreatefrompng($imagePath);
if ($outBool === false) $outExt = 'png';
break;
case $type === IMAGETYPE_GIF:
$image = imagecreatefromgif($imagePath);
if ($outBool === false) $outExt = 'gif';
break;
case $type === IMAGETYPE_BMP:
$image = imagecreatefrombmp($imagePath);
if ($outBool === false) $outExt = 'bmp';
break;
case $type === IMAGETYPE_WEBP:
$image = imagecreatefromwebp($imagePath);
if ($outBool === false) $outExt = 'webp';
}
$newImage = imagecreatetruecolor($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);
// Rotate image on iOS
if(function_exists('exif_read_data') && $exif = exif_read_data($imagePath, 'IFD0'))
{
if(isset($exif['Orientation']) && isset($exif['Make']) && !empty($exif['Orientation']) && preg_match('/(apple|ios|iphone)/i', $exif['Make'])) {
switch($exif['Orientation']) {
case 8:
if ($width > $height) $newImage = imagerotate($newImage,90,0);
break;
case 3:
$newImage = imagerotate($newImage,180,0);
break;
case 6:
$newImage = imagerotate($newImage,-90,0);
break;
}
}
}
switch (true)
{
case in_array($outExt, ['jpg', 'jpeg']) === true: $success = imagejpeg($newImage, $newPath);
break;
case $outExt === 'png': $success = imagepng($newImage, $newPath);
break;
case $outExt === 'gif': $success = imagegif($newImage, $newPath);
break;
case $outExt === 'bmp': $success = imagebmp($newImage, $newPath);
break;
case $outExt === 'webp': $success = imagewebp($newImage, $newPath);
}
if ($success === false)
{
return null;
}
return $newPath;
}
回答7:
I created an easy-to-use library for image resizing. It can be found here on Github.
An example of how to use the library:
// 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');
Other features, should you need them, are:
- Quick and easy resize - Resize to landscape, portrait, or auto
- Easy crop
- Add text
- Quality adjustment
- Watermarking
- Shadows and reflections
- Transparency support
- Read EXIF metadata
- Borders, Rounded corners, Rotation
- Filters and effects
- Image sharpening
- Image type conversion
- BMP support
回答8:
ZF cake:
<?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 ));
}
}
回答9:
I found a mathematical way to get this job done
Github repo - https://github.com/gayanSandamal/easy-php-image-resizer
Live example - 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);
}
?>
回答10:
You can give a try to TinyPNG PHP library. Using this library your image gets optimized automatically during resizing process. All you need to install the library and get an API key from https://tinypng.com/developers. To install a library, run the below command.
composer require tinify/tinify
After that, your code is as follows.
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
));
$resized->toFile("thumbnail.jpg"); //resized image
I have a written a blog on the same topic http://artisansweb.net/resize-image-php-using-tinypng
回答11:
I would suggest an easy way:
function resize($file, $width, $height) {
switch(pathinfo($file)['extension']) {
case "png": return imagepng(imagescale(imagecreatefrompng($file), $width, $height), $file);
case "gif": return imagegif(imagescale(imagecreatefromgif($file), $width, $height), $file);
default : return imagejpeg(imagescale(imagecreatefromjpeg($file), $width, $height), $file);
}
}
来源：https://stackoverflow.com/questions/14649645/resize-image-in-php