PHP GD Compress Images

0-PHP-GD-COMPRESS-IMG.MD

HOW TO COMPRESS IMAGES USING PHP GD

https://code-boxx.com/compress-images-php/

DEMO IMAGE

NOTES

Ensure that the GD extension extension=gd (gd2 prior to PHP8) is enabled in the php.ini file.

LICENSE

Copyright by Code Boxx

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

1-simple.php

<?php
// (A) IMAGE OBJECT
$img = imagecreatefrompng("demo.png");
imagepalettetotruecolor($img);

// (B) COMPRESS IMAGE
// (B1) BY REDUCING QUALITY
imagejpeg($img, "demoA.jpg", 50);

// (B2) BY CHANGING IMAGE FILE TYPE & REDUCING QUALITY
imagewebp($img, "demoA.webp", 50);
echo "DONE";

2-resize.php

<?php
// (A) IMAGE OBJECT
$img = imagecreatefrompng("demo.png");
imagepalettetotruecolor($img);

// (B) RESIZE IMAGE
$img = imagescale($img, 200, 200);

// (C) COMPRESS IMAGE
imagewebp($img, "demoB.webp", 50);
echo "DONE";

3-packi.php

<?php
function packi ($from, $to, $mw=null, $mh=null, $quality=null) {
  // (A) CHECKS
  // (A1) SOURCE IMAGE IS READABLE
  if (!is_readable($from)) { exit("Cannot read $from"); }

  // (A2) ALLOWED IMAGE FILE FORMATS
  $extFrom = strtolower(pathinfo($from, PATHINFO_EXTENSION));
  $extTo = strtolower(pathinfo($to, PATHINFO_EXTENSION));
  if (!in_array($extFrom, ["jpeg", "jpg", "gif", "png", "bmp", "webp"])) { exit("$from - Invalid file format"); }
  if (!in_array($extTo, ["jpeg", "jpg", "gif", "png", "webp"])) { exit("$from - Invalid file format"); }

  // (B) OPEN SOURCE IMAGE
  $fn = "imagecreatefrom" . ($extFrom=="jpg" ? "jpeg" : $extFrom);
  $img = $fn($from);

  // (C) RESIZE IMAGE
  if ($mw!=null || $mh!=null) {
    // (C1) SOURCE IMAGE DIMENSIONS
    $sw = imagesx($img);
    $sh = imagesy($img);

    // (C2) RESIZE RATIO
    if ($mw != null && $sw>$mw) { $rw = $mw / $sw; } else { $rw = 1; }
    if ($mh != null && $sh>$mh) { $rh = $mh / $sh; } else { $rh = 1; }

    // (C3) RESIZE USING THE SMALLER RATIO
    if ($rw!=1 || $rh!=1) {
      $rr = $rw<$rh ? $rw : $rh ;
      $img = imagescale($img, floor($rr * $sw), floor($rr * $sh));
    }
  }

  // (D) SAVE & COMPRESS IMAGE
  // jpg : 0 to 100
  // webp : -1 (default), 0 to 100
  // png : -1 (default), 0 (none) to 9
  // gif : na (no compression)
  if ($extTo=="gif") { imagegif($img, $to); }
  else {
    if ($extTo=="jpg" && ($quality==null || !is_numeric($quality) || $quality<0 || $quality>100)) { $quality = 30; }
    if ($extTo=="webp" && ($quality==null || !is_numeric($quality) || $quality<-1 || $quality>100)) { $quality = -1; }
    if ($extTo=="png" && ($quality==null || !is_numeric($quality) || $quality<-1 || $quality>9)) { $quality = -1; }
    $fn = "image" . ($extTo=="jpg" ? "jpeg" : $extTo);
    $fn($img, $to, $quality);
  }
  return true;
}

// (E) GO!
packi("D:/http/demo.png", "D:/http/demoC.jpg");
packi("D:/http/demo.png", "D:/http/demoC.png", 200, 0);    // max width 200
packi("D:/http/demo.png", "D:/http/demoC.gif", 0, 200);    // max height 200
packi("D:/http/demo.png", "D:/http/demoC.webp", 200, 400); // max width 200, max height 400
echo "DONE";