image_manip.inc

<?php
require_once dirname(__FILE__).'/../general/file_system.inc';

class Image_Manip
{


    public static function gradientPalette($input, $output, $colour_a, $colour_b)
    {
        require_once dirname(__FILE__).'/../colour/colour.inc';

        if (!($image = Image_Manip::fromFile($input))) {
            trigger_error('Unable to open image for recolourizing: '.$input);
            return false;
        }

        // Anylize colours and calculate difference colour
        $ca_array = Colour::htmlToRgb($colour_a);
        $cb_array = Colour::htmlToRgb($colour_b);
        $diff = Array(
                    'r' => ($cb_array['r'] - $ca_array['r']),
                    'g' => ($cb_array['g'] - $ca_array['g']),
                    'b' => ($cb_array['b'] - $ca_array['b']),
                );

        // Get the number of colours in a palette
        $palette_size = imageColorsTotal($image);
        // Replace colours in palette
        for ($i = 0; $i < $palette_size; $i++) {
            // because the image is greyscale each value for the R, G & B will be the same
            // therefore to find the percentage white this index is we divide by 256
            $colour = imageColorsForIndex ($image, $i);
            $fraction = (double) ($colour['red'] / 256);

            $r = (int) (255 * ($ca_array['r'] + $diff['r'] * $fraction));
            $g = (int) (255 * ($ca_array['g'] + $diff['g'] * $fraction));
            $b = (int) (255 * ($ca_array['b'] + $diff['b'] * $fraction));
            imageColorSet($image,$i, $r, $g, $b);
        }

        // Output result to file
        $ret_val = Image_Manip::toFile($image, $output);
        imageDestroy($image);
        return $ret_val;

    }//end gradientPalette()


    public static function remapColour($input, $output, $colour_map, $tolerance=0.2)
    {
        require_once dirname(__FILE__).'/../colour/colour.inc';

        if (!($image = Image_Manip::fromFile($input))) {
            trigger_error('Unable to open image for recolourizing: '.$input);
            return false;
        }

        // Get the number of colours in a palette
        $palette_size = imageColorsTotal($image);

        // Replace colours in palette
        for ($i = 0; $i < $palette_size; $i++) {
            $colour = imageColorsForIndex($image, $i);
            // Convert to HTML colour
            $colour = Colour::rgbToHtml(Colour::rgb($colour['red'],$colour['green'],$colour['blue']));
            $rgb = Colour::htmlToRgb(Colour::remap($colour,$colour_map,$tolerance));
            $r = $rgb['r'] * 255;
            $g = $rgb['g'] * 255;
            $b = $rgb['b'] * 255;
            imagecolorset($image,$i, $r, $g, $b);
        }

        // Output result to file
        $ret_val = Image_Manip::toFile($image, $output);
        imageDestroy($image);
        return $ret_val;

    }//end remapColour()


    public static function resize($input, $output, $w, $h)
    {
        // NOTE: $s_* = source image vars, $d_* = destination image vars
        $s_img = Image_Manip::fromFile($input);

        // transparency needs to be handled separately for GIF/PNG
        switch (get_file_type($output)) {
        case 'gif':
            $d_img = imageCreate($w, $h);
            // preserve GIF transparency, if any
            $colorTransparent = imagecolortransparent($s_img);
            if ($colorTransparent > -1) {
                imagepalettecopy($d_img,$s_img);
                imagefill($d_img,0,0,$colorTransparent);
                imagecolortransparent($d_img, $colorTransparent);
            }
            break;
        case 'png':
            // preserve PNG transparency
            $d_img = imageCreateTrueColor($w, $h);
            imagealphablending( $d_img, false );
            imagesavealpha( $d_img, true );
            break;
        default:
            $d_img = imageCreateTrueColor($w, $h);
        }

        $ret_val = false;

        $ret_val = ImageCopyResampled($d_img, $s_img, 0, 0, 0, 0, $w, $h, imageSx($s_img), imageSy($s_img));
        imageDestroy($s_img); // kill this to save memory before save

        if ($ret_val) {
            $ret_val = Image_Manip::toFile($d_img, $output);
        }

        // finally destory dest image
        imageDestroy($d_img);

        return $ret_val;

    }//end resize()


    public static function fromFile($input)
    {
        switch (get_file_type($input)) {
            case 'gif' :
                if ($image = imageCreateFromGif ($input)) {
                    return $image;
                } else {
                    trigger_error('Unable to open GIF : '.$input);
                }
            break;
            case 'png' :
                if ($image = imageCreateFromPNG($input)) {
                    return $image;
                } else {
                    trigger_error('Unable to open PNG : '.$input);
                }
            break;
            case 'jpg' :
            case 'jpeg':
                if ($image = imageCreateFromJPEG($input)) {
                    return $image;
                } else {
                    trigger_error('Unable to open JPEG : '.$input);
                }
            break;
            default:
                trigger_error('Unable to open unknown image type : '.$input);
            break;
        }
        return false;

    }//end fromFile()


    public static function toFile($image, $output, $jpeg_quality=80)
    {
        // Output result to file
        switch (get_file_type($output)) {
            case 'gif' :
                if (imageGif($image, $output)) return true;
            break;

            case 'png' :
                if (imagePNG($image, $output)) return true;
            break;

            case 'jpg' :
            case 'jpeg':
                if (imageJPEG($image, $output, $jpeg_quality)) {
                    return TRUE;
                }
            break;

            default:
                trigger_error('Unable to write unknown image type : '.$output, E_USER_WARNING);
            break;
        }

        trigger_error('Unable to output image : '.$output, E_USER_WARNING);
        return FALSE;

    }//end toFile()


}//end class
?>