在PHP中调整图片大小


96

我想编写一些PHP代码,该代码会自动将通过表单上传的所有图片的大小调整为147x147px,但我不知道如何处理(我是相对的PHP新手)。

到目前为止,我已经成功上传了图像,可以识别文件类型并清理了名称,但是我想在代码中添加调整大小功能。例如,我有一个测试图像,大小为2.3MB,尺寸为1331x1331,我希望代码缩小尺寸,我想它也会极大地压缩图像的文件大小。

到目前为止,我有以下几点:

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);


无需更改upload_max_filesizein php.ini,首先可以上传大小大于upload_max_filesize?的文件。是否有机会将图像尺寸调整为大于upload_max_filesize?在不改变upload_max_filesizephp.ini
RCH

Answers:


140

您需要使用PHP的ImageMagickGD函数来处理图像。

以GD为例,它就像...

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;
}

您可以像下面这样调用此函数...

$img = resize_image(‘/path/to/some/image.jpg’, 200, 200);

从个人经验来看,GD的图像重采样确实也大大减小了文件大小,尤其是在对原始数码相机图像重采样时。


谢谢!原谅我的无知,但是那在我已经获得的代码中会放在哪里,函数调用会在哪里?我是说对了,在我要插入数据库的地方,而不是插入$ n,而是插入$ img?还是将$ n结构化为$ n =($ img = resize_image('/ path / to / some / image.jpg',200,200));?
Alex Ryans

1
您是否将图像存储为BLOBs?我建议将图像存储在文件系统中,并在数据库中插入引用。我还建议阅读完整的GD(或ImageMagick)文档,以了解可用的其他选项。
伊恩·阿特金

17
请注意,此解决方案仅适用于JPEG。您可以使用以下任意一种替换imagecreatefromjpeg:imagecreatefromgd,imagecreatefromgif,imagecreatefrompng,imagecreatefromstring,imagecreatefromwbmp,imagecreatefromxbm,imagecreatefromxpm以处理不同的图像类型。
克里斯·汉森

2
@GordonFreeman感谢您提供了出色的代码段,但其中存在一个小故障,请在高度部分添加abs()ceil($width-($width*abs($r-$w/$h)))相同。在某些情况下是必需的。
Arman P.

4
要在文件系统中保存调整大小的图像,请imagejpeg($dst, $file);在该imagecopyresampled($dst,...行之后添加。$file如果您不想覆盖原始文件,请进行更改。
wkille

23

此资源(链接断开)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段以创建满足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
    
}

您还需要包括此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;
   }      
 
}
?>

1
您的样品是最好的。它可以直接在Zend框架中工作,而无需制作喜剧,戏剧和头发。竖起大拇指

我认为您需要的所有代码都应包含在我的答案中,但这也可能会有所帮助:gist.github.com/arrowmedia/7863973
ban-geoengineering

18

简单使用PHP函数(imagescale):

句法:

imagescale ( $image , $new_width , $new_height )

例:

步骤:1读取文件

$image_name =  'path_of_Image/Name_of_Image.jpg|png';      

步骤:2:加载图像文件

 $image = imagecreatefromjpeg($image_name); // For JPEG
//or
 $image = imagecreatefrompng($image_name);   // For PNG

步骤:3:我们的救生员以'_'开头| 缩放图像

   $imgResized = imagescale($image , 500, 400); // width=500 and height = 400
//  $imgResized is our final product

注意:imagescale将适用于(PHP 5> = 5.5.0,PHP 7)

来源:点击以了解更多


PHP 5.6.3的最佳解决方案>
Pattycake Jr,

12

如果您不关心宽高比(即要强制将图像缩放到特定尺寸),这是一个简化的答案

// 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,并按如下所示传递上载文件的绝对路径:

 // 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位置,如下所示:

 // again for jpg
 imagejpeg($img, 'path/newimage.jpg');

希望这对某人有帮助。检查这些链接以获取更多有关调整 Imagick :: resizeImageimagejpeg()大小的信息。


如果不更改upload_max_filesizein php.ini,首先您不能上传大小超过的文件upload_max_filesize。是否有机会来调整大小的图像中超过upload_max_filesize不改变upload_max_filesizephp.ini
RCH

6

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);
        }

6

重要说明:对于动画(调整动画的Webp或gif)大小,结果将是未动画但从第一帧开始调整大小的图像!(原始动画保持不变...)

我将其创建到我的php 7.2项目(肯定为imagebmp(PHP 7> = 7.2.0):php / manual / function.imagebmp)中,关于techfry.com/php-tutorial,并且带有GD2(因此没有第3方库)和与Nico Bistolfi的答案非常相似,但是可以使用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,而无需修改原始文件,并且所有功能都集成在一个函数中,准备使用(复制并粘贴到您的项目中)。(您可以使用第五个参数设置新文件的扩展名,或者,如果要保留原始名称,则可以保留它):

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;
}

你很棒!这是简单干净的解决方案。我遇到了Imagick模块的问题,并通过此简单的类解决了问题。谢谢!
Ivijan StefanStipić19年

太好了,如果您希望以后可以添加另一个更新,可以对此进行一些改进。
Ivijan StefanStipić,19年

当然!我仍然没有时间构建动画大小调整部分……
danigore

@danigore,如何调整原始图像的大小(.cr2, .dng, .nef等等)?GD2没有任何支持,经过很多努力,我能够设置ImageMagick。但是,它在读取文件时因连接超时错误而失败。并且,也没有错误日志..
克里希纳·奇布洛卢

1
@danigore我在您的函数中添加了自动图像旋转功能,以解决Apple问题。
Ivijan StefanStipić,19年

5

我创建了一个易于使用的库来调整图像大小。可以在Github上找到它。

有关如何使用该库的示例:

// 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');

您需要的其他功能包括:

  • 快速轻松地调整大小-调整为横向,纵向或自动调整大小
  • 易收割
  • 添加文字
  • 质量调整
  • 水印
  • 阴影和倒影
  • 透明性支持
  • 读取EXIF元数据
  • 边框,圆角,旋转
  • 滤镜和效果
  • 影像锐化
  • 图像类型转换
  • BMP支持

这挽救了我的一天。但是,我有一个小小的通知,通知我像我这样搜寻3天的人,并且对于寻找任何调整大小的解决方案将失去希望。如果您将来会看到未定义的索引通知,请仅查看以下链接:github.com/Oberto/php-image-magician/pull/16/commits并将更改应用于文件。它将100%正常工作。
Hema_Elmasry

1
嘿,@ Hema_Elmasry。仅供参考,我刚刚将这些更改合并为主要内容:)
Jarrod,

好的,对不起,我没有注意到。但是我有一个问题。当我将尺寸调整为较小的分辨率且质量未更改时,显示的图像质量会大大降低。您之前是否发生过类似的事情?因为我仍然找不到解决方案。
Hema_Elmasry

2

这是@Ian Atkin'给出的答案的扩展版本。我发现它工作得非常好。对于较大的图像是:)。如果不小心,实际上可以使较小的图像变大。更改:-支持jpg,jpeg,png,gif,bmp文件-保留.png和.gif的透明度-仔细检查原始尺寸是否较小-覆盖直接给出的图像(这是我需要的)

就是这样 该函数的默认值为“黄金法则”

function resize_image($file, $w = 1200, $h = 741, $crop = false)
   {
       try {
           $ext = pathinfo(storage_path() . $file, PATHINFO_EXTENSION);
           list($width, $height) = getimagesize($file);
           // if the image is smaller we dont resize
           if ($w > $width && $h > $height) {
               return true;
           }
           $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;
               }
           }
           $dst = imagecreatetruecolor($newwidth, $newheight);

           switch ($ext) {
               case 'jpg':
               case 'jpeg':
                   $src = imagecreatefromjpeg($file);
                   break;
               case 'png':
                   $src = imagecreatefrompng($file);
                   imagecolortransparent($dst, imagecolorallocatealpha($dst, 0, 0, 0, 127));
                   imagealphablending($dst, false);
                   imagesavealpha($dst, true);
                   break;
               case 'gif':
                   $src = imagecreatefromgif($file);
                   imagecolortransparent($dst, imagecolorallocatealpha($dst, 0, 0, 0, 127));
                   imagealphablending($dst, false);
                   imagesavealpha($dst, true);
                   break;
               case 'bmp':
                   $src = imagecreatefrombmp($file);
                   break;
               default:
                   throw new Exception('Unsupported image extension found: ' . $ext);
                   break;
           }
           $result = imagecopyresampled($dst, $src, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
           switch ($ext) {
               case 'bmp':
                   imagewbmp($dst, $file);
                   break;
               case 'gif':
                   imagegif($dst, $file);
                   break;
               case 'jpg':
               case 'jpeg':
                   imagejpeg($dst, $file);
                   break;
               case 'png':
                   imagepng($dst, $file);
                   break;
           }
           return true;
       } catch (Exception $err) {
           // LOG THE ERROR HERE 
           return false;
       }
   }

很棒的功能@DanielDoinov-感谢您发布它-快速问题:有没有一种方法只能传递宽度,让函数根据原始图像相对地调整高度?换句话说,如果原始尺寸为400x200,我们能否告诉函数我们希望新的宽度为200,然后让函数计算出高度应为100?
marcnyc

关于您的条件表达式,如果执行,则我认为执行大小调整技术没有任何意义$w === $width && $h === $height。想一想。应该>=>=比较。@丹尼尔
mickmackusa

1

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 ));        
      }



  }  

1

我找到了完成这项工作的数学方法

Github回购-https: //github.com/gayanSandamal/easy-php-image-resizer

实时示例-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);
}
?>

0

您可以尝试使用TinyPNG PHP库。使用此库,可以在调整大小过程中自动优化图像。您需要安装库并从https://tinypng.com/developers获取API密钥。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

我在同一主题上写了一个博客http://artisansweb.net/resize-image-php-using-tinypng


0

我建议一种简单的方法:

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);
    }
}

0
private function getTempImage($url, $tempName){
  $tempPath = 'tempFilePath' . $tempName . '.png';
  $source_image = imagecreatefrompng($url); // check type depending on your necessities.
  $source_imagex = imagesx($source_image);
  $source_imagey = imagesy($source_image);
  $dest_imagex = 861; // My default value
  $dest_imagey = 96;  // My default value

  $dest_image = imagecreatetruecolor($dest_imagex, $dest_imagey);

  imagecopyresampled($dest_image, $source_image, 0, 0, 0, 0, $dest_imagex, $dest_imagey, $source_imagex, $source_imagey);

  imagejpeg($dest_image, $tempPath, 100);

  return $tempPath;

}

这是基于很好的解释的适应性解决方案。这个家伙做了一步一步的解释。希望大家喜欢。

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