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PHP: Auto-crop the image Share on Vkontakte

This class can be used to crop images by removing edges with same color. It can load a GIF, JPEG or PNG image and scans it to detect edges color, so it crops the image to remove the edge areas that have the same color around it. The cropped image is outputted in the same format as the original image.

 originalSource = $source;
            if($destination)
            {
                $this->destinationSource = $destination;
            }
            
            return $this->cropImage();
        }
        else return false;
    }
    
    /**
     * @return     boolean
     */
    private function cropImage()
    {
        // first we get the filetype
        $fileType = mime_content_type($this->originalSource);
        if(substr($fileType, 0, 5) == "image")
        {
            switch($fileType)
            {
                case "image/jpeg":
                    $this->originalImage = imagecreatefromjpeg($this->originalSource);
                    $this->destinationImage = imagecreatefromjpeg($this->originalSource);
                    break;
                
                case "image/gif":
                    $this->originalImage = imagecreatefromgif($this->originalSource);
                    $this->destinationImage = imagecreatefromgif($this->originalSource);
                    break;
                    
                case "image/png":
                    $this->originalImage = imagecreatefrompng($this->originalSource);
                    $this->destinationImage = imagecreatefrompng($this->originalSource);
                    break;
                    
                default:
                    return false;
                    break;
            }
            if($this->originalImage)
            {
                $this->imagecolorswap($this->destinationImage);
                $this->edge = $this->imageGetEdges($this->destinationImage, 250, 250, 250);
                imagedestroy($this->destinationImage);
                
                $newWidth = $this->edge[0]-$this->edge[2];
                $newHeight = $this->edge[1]-$this->edge[3];
                $this->destinationImage = imagecreatetruecolor($newWidth, $newHeight);
                imagecopyresized(
                    $this->destinationImage, 
                    $this->originalImage, 
                    0, 
                    0, 
                    $this->edge[2], 
                    $this->edge[3], 
                    $newWidth, 
                    $newHeight, 
                    $newWidth, 
                    $newHeight
                );
                
                return $this->outputImage();
            }
            else return false;
        }
        else return false;
    }
    
    /**
     * @return boolean
     */
    private function outputImage()
    {
        if(count($this->edge) == 4)
        {
            // output the image....as what?
            if($this->destinationSource)
            {    // save to file
                // get the destination extention so we know how to save this image
                $fileType = strtolower(substr($this->destinationSource,strripos($this->destinationSource, ".")));
                switch($fileType)
                {
                    case ".jpg":
                    case ".jpeg":
                        imagejpeg($this->destinationImage, $this->destinationSource);
                        break;
                        
                    case ".png":
                        imagepng($this->destinationImage, $this->destinationSource);
                        break;
                        
                    case ".gif":
                        imagegif($this->destinationImage, $this->destinationSource);
                        break;    
                }
            }
            else
            {    // inline display
                $fileType = mime_content_type($this->originalSource);
                header('Content-type: '.$fileType);
                switch($fileType)
                {
                    case "image/jpeg":
                        imagejpeg($this->destinationImage);
                        break;
                        
                    case "image/png":
                        imagepng($this->destinationImage);
                        break;
                        
                    case "image/gif":
                        imagegif($this->destinationImage);
                        break;    
                }
            }
            return true;
        }
        else return false;
    }
    
    /**
     * @param $img (image resource)
     * @param $red (color red)
     * @param $green (color green)
     * @param $blue (color blue)
     * @return array(X1, Y1, X2, Y2) (right, bottom, left, top)
     * @brief    X1,Y1 are the bottom right positions and X2,Y2 are the top left position
     */
    private function imageGetEdges(&$img, $red, $green, $blue)
    {
        // where the color starts thats te edge
        $margin = 30;
        $width = imagesx($img);
        $height = imagesy($img);
        
        $returnX = $this->margin;
        $returnY = $this->margin;
        $returnXmin = $width-($this->margin);
        $returnYmin = $height-($this->margin);
        $Xvalues = array();
        $Yvalues = array();
        
        $searchColor = imagecolorclosest($img, $red, $green, $blue);
        for($x = $margin; $x<($width-$this->margin); $x=$x+1)
        {
            for($y = $margin; $y<($height-$this->margin); $y=$y+1)
            {
                $color = imagecolorat($img, $x, $y);
                if($color != $searchColor)
                {
                    $aprocX = floor($x/$this->correction)*$this->correction;
                    $aprocY = floor($y/$this->correction)*$this->correction;
                    if(isset($Xvalues[$aprocX]))
                        $Xvalues[$aprocX] += 1;
                    else
                        $Xvalues[$aprocX] = 0;
                        
                    if(isset($Yvalues[$aprocY]))
                        $Yvalues[$aprocY] += 1;
                    else
                        $Yvalues[$aprocY] = 0;
                }
            }
        }
        // average X and Y
        $returnX = $this->margin;
        $returnY = $this->margin;
        $returnXmin = $width-($this->margin);
        $returnYmin = $height-($this->margin);
        foreach($Xvalues AS $X => $aantal)
        {
            if($X > $returnX && $aantal > 8)
            {
                $returnX = $X;
            }
            if($X < $returnXmin && $aantal > 8)
            {
                $returnXmin = $X;
            }
        }
        foreach($Yvalues AS $Y => $aantal)
        {
            if($Y > $returnY && $aantal > 8)
            {
                $returnY = $Y;
                $maxAantalY = $aantal;
            }
            if($Y < $returnYmin && $aantal > 8)
            {
                $returnYmin = $Y;
            }
        }
        
        $testmargin = $this->margin + $this->correction;
    
        if($returnX >= $width-($testmargin))
            $returnX = $width;
        else
            $returnX += $this->correction;
            
        if($returnY >= $height-($testmargin))
            $returnY = $height;
        else
            $returnY += $this->correction;
            
        if($returnXmin <= $testmargin)
            $returnXmin  = 0;
        else
            $returnXmin -= $this->correction;
            
        if($returnYmin <= $testmargin)
            $returnYmin = 0;
        else
            $returnYmin -= $this->correction;
            
        return array($returnX, $returnY, $returnXmin, $returnYmin);
    }
    
    private function imagecolorswap(&$img) 
    {    
        // First we remove the background
        imagefilter($img, IMG_FILTER_SMOOTH, 10);
        imagefilter($img, IMG_FILTER_EDGEDETECT);
        imagefilter($img, IMG_FILTER_CONTRAST, -90);
        imagefilter($img, IMG_FILTER_BRIGHTNESS, -20);
        //imagefilter($img, IMG_FILTER_BRIGHTNESS, -40);
        imagefilter($img, IMG_FILTER_CONTRAST, 20);
        
        // remove color: 120 120 120 TO 180 180 180
        if (!($t = imagecolorstotal($img))) 
        {
            $t = 250;
            imagetruecolortopalette($img, 1, $t);
        }
        for ($c = 0; $c < $t; $c++) 
        { 
            $cc = imagecolorclosest($img, 150, 150, 150);
            imagecolorset($img, $cc, 250, 250, 250);
        }
        imagefilter($img, IMG_FILTER_COLORIZE, 0, 0, 0);
    }
}
?> 


Tag: PHP, image, Crop, Auto-crop

2 Comments

  1. Avatar
    dmitrij.davidenko

    30th May 2013, 07:09

    Допишите что требуется наличие библиотеки GD

  2. Avatar
    Denis

    30th May 2013, 12:26

    Есть же Imagick, для кропа 2 строчки кода