Resize image in PHP

Resize image in PHP

You need to use either PHPs ImageMagick or GD functions to work with images.

With GD, for example, its 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, GDs image resampling does dramatically reduce file size too, especially when resampling raw digital camera images.

Simply use PHPs GD functions (like imagescale):

Syntax:

imagescale ( $image , $new_width , $new_height )

Example:

Step: 1 Read the file

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

Step: 2: Load the Image File

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

Step: 3: Our Life-saver comes in _ | Scale the image

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

Note: imagescale will work for (PHP 5 >= 5.5.0, PHP 7)

Step: 4: Save the Resized image to your desired directory.

imagejpeg($imgResized, path_of_Image/Name_of_Image_resized.jpg); //for jpeg
imagepng($imgResized, path_of_Image/Name_of_Image_resized.png); //for png

Source : Click to Read more

Resize image in PHP

This resource(broken link) 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;
   }      
 
}
?>