Dimensionar a imagem em PHP

É necessário usar as funções do PHP ImageMagick ou GD para trabalhar com imagens.

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;
}

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

Este recurso também vale a pena considerar-algum código muito arrumado que usa GD. No entanto, modifiquei o seu excerto de código final para criar esta função que satisfaz os requisitos da OPs...

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

}

Também terá de incluir este ficheiro PHP...

<?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;
   }      

}
?>

Se você não se importa com a ração de aspecto (ou seja, você quer forçar a imagem para uma dimensão particular), aqui está uma resposta simplificada

// 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;
}

 // jpg  change the dimension 750, 450 to your desired values
 $img = resize_imagejpg('path/image.jpg', 750, 450);

O valor de retorno $img é um objecto de recurso. Podemos salvar para um novo local ou anular o original como abaixo:

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

/**
         * 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);
        }

Bolo ZF:

<?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 ));        
      }



  }  

composer require tinify/tinify

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

Criei uma biblioteca fácil de usar para redimensionar as imagens. Pode ser encontrado aqui no Github.

Um exemplo de como usar a Biblioteca:

// 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');

Outras características, se precisar delas, são:

• dimensionamento rápido e fácil-dimensionamento para paisagem, retrato ou auto
• cultura fácil
• adicionar texto
• ajustamento da Qualidade
Marca De Água
• Sombras e reflexões
• apoio à transparência
• ler EXIF metadados
• contornos, cantos arredondados, rotação
• Filtros e efeitos
• aumento da imagem
• conversão do tipo de imagem
• suporte BMP

Eu recomendaria que usasses piio.co , uma vez que tenha carregado as suas imagens para o seu armazenamento, basta usar o url original da imagem na sua marca <img /> e a biblioteca fará automaticamente o redimensionamento para si.

A tua marca de imagem ficará assim:

<img data-piio="/image/gallery/p/image1.jpg" />

Depois de inicializar o programa do Piio, ele irá redimensionar automaticamente a imagem e servi-la a partir de um CDN.

Se quiseres. faça manualmente , então eu recomendo que você use as funções nativas do php, isto irá usar a biblioteca GD. Por exemplo, se quiser redimensionar um JPEG, poderá começar por:

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);

Para enviar directamente a imagem:

imagejpeg($thumb);

Para gravar a imagem num ficheiro:

imagejpeg($thumb, 'filepath/image.jpg');

GitHub repo - https://github.com/gayanSandamal/easy-php-image-resizer

Exemplo Vivo - 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);
}
?>

Basta usar a função php: dada como

// read the img
$img = imagecreatefromjpeg("source_of_img.jpg");

// Now read the iamge width = 200 and height = 200
$imgresize = imagescale($dp,200,200);