image-resize-bg.php

<?php   

class ResizeImage {
    var $image;
    var $image_type;
    static function makeDir($path) {
        return is_dir($path) ||  mkdir($path, 0777, true);
    }
    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) {
        $image_type=$this->image_type;
        if( $image_type == IMAGETYPE_JPEG ) {
            imagejpeg($this->image,$filename,$compression);
        } elseif( $image_type == IMAGETYPE_GIF ) {
            imagegif($this->image,$filename);  
        } elseif( $image_type == IMAGETYPE_PNG ) {
            imagealphablending($this->image, false);
            imagesavealpha($this->image,true);
            imagepng($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,$height);
    }   
    function resizeBackground($width,$height,$forcesize='n', $bg="transparent") {
        if ($forcesize == 'n') {
          if ($width > $this->getWidth() && $height > $this->getHeight()){
              $width = $this->getWidth();
              $height = $this->getHeight();
          }
        }
        $new_image = imagecreatetruecolor($width, $height);

        if(($this->image_type == IMAGETYPE_GIF) || ($this->image_type==IMAGETYPE_PNG)){
            //Por defecto es transparente
            $bgSet=imagecolorallocatealpha($new_image, 255, 255, 255, 127);
            //Aquí el color blanco
            if($bg=="white") {
              $bgSet=imagecolorallocate($im,255,255,255);                
            }
            imagealphablending($new_image, false);
            imagesavealpha($new_image,true);
            imagefilledrectangle($new_image, 0, 0, $width, $height, $bgSet);
        }
        imagecopyresampled($new_image, $this->image, 0, 0, 0, 0, $width, $height, $this->getWidth(), $this->getHeight());
        $this->image = $new_image;   
    }
}
/*
   $image = new ResizeImage();
   $image->load('picture.jpg');
   $image->resizeBackground(500,500,'n','white');
   $image->save('picture2.jpg');
*/