Ale*_*ans 75 php image-processing image-upload image-resizing
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 />" . $query);
Gor*_*man 124
您需要使用PHP的ImageMagick或GD函数来处理图像.
以GD为例,它就像......一样简单
function resize_image($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......
$img = resize_image(‘/path/to/some/image.jpg’, 200, 200);
从个人经验来看,GD的图像重采样确实大大减少了文件大小,特别是在重新采样原始数码相机图像时.
ban*_*ing 19
这个资源也值得考虑 - 一些使用GD的非常整洁的代码.但是,我修改了他们的最终代码片段以创建符合OP要求的此功能...
function store_uploaded_image($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 = $new_image;
}
}
?>
小智 12
如果您不关心纵横比(即您想要将图像强制为特定维度),这里有一个简化的答案
// for jpg
function resize_imagejpg($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
Mab*_*abd 10
只是简单地使用php函数：
// Read the image
$img = imagecreatefromjpeg("source_of_img.jpg");
// Now resize the image width = 200 and height = 200
$imgresize = imagescale($img, 200, 200);
希望对您有用。
/**
* 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);
}
我创建了一个易于使用的图像调整库。它可以在 Github上找到。
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：
（重要提示：在动画（动画 webp 或 gif）调整大小的情况下，结果将不是动画，而是从第一帧开始调整大小的图像！（原始动画保持不变......）
我在我的php 7.2项目中创建了这个（例如 imagebmp 肯定（PHP 7 >= 7.2.0）：php/manual/function.imagebmp）关于techfry.com/php-tutorial，使用 GD2，（所以没有第三方库）和与 Nico Bistolfi 的答案非常相似，但适用于所有五种基本图像模仿类型（png、jpeg、webp、bmp 和 gif），创建一个新的调整大小的文件，而不修改原始文件，并且所有内容都在一个函数中，并且准备使用（复制并粘贴到您的项目）。（您可以使用第五个参数设置新文件的扩展名，或者如果您想保留原始文件，则保留它）：
function createResizedImage(
string $imagePath = '',
string $newPath = '',
int $newWidth = 0,
int $newHeight = 0,
string $outExt = 'DEFAULT'
) : ?string
{
if (!$newPath or !file_exists ($imagePath)) {
return null;
}
$types = [IMAGETYPE_JPEG, IMAGETYPE_PNG, IMAGETYPE_GIF, IMAGETYPE_BMP, IMAGETYPE_WEBP];
$type = exif_imagetype ($imagePath);
if (!in_array ($type, $types)) {
return null;
}
list ($width, $height) = getimagesize ($imagePath);
$outBool = in_array ($outExt, ['jpg', 'jpeg', 'png', 'gif', 'bmp', 'webp']);
switch ($type) {
case IMAGETYPE_JPEG:
$image = imagecreatefromjpeg ($imagePath);
if (!$outBool) $outExt = 'jpg';
break;
case IMAGETYPE_PNG:
$image = imagecreatefrompng ($imagePath);
if (!$outBool) $outExt = 'png';
break;
case IMAGETYPE_GIF:
$image = imagecreatefromgif ($imagePath);
if (!$outBool) $outExt = 'gif';
break;
case IMAGETYPE_BMP:
$image = imagecreatefrombmp ($imagePath);
if (!$outBool) $outExt = 'bmp';
break;
case IMAGETYPE_WEBP:
$image = imagecreatefromwebp ($imagePath);
if (!$outBool) $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']): $success = imagejpeg ($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) {
return null;
}
return $newPath;
}