blurred.module

<?php
function blurred_image_effect_info() {
    $effects = array();
    $effects['advance_resize'] = array(
        'label' => t('Blurred background'),
        'help' => t('Creates image with fixed proportion and blurred background.'),
        'effect callback' => 'blurred_effect',
        'dimensions callback' => 'image_resize_dimensions',
        'form callback' => 'image_resize_form',
        'summary theme' => 'image_resize_summary',
    );
    return $effects;
}

function blurred_effect(&$image, $data) {
    if (!blurred_background($image, $data['width'], $data['height'])) {
        watchdog('image', 'Image resize within Blurred module failed using the %toolkit toolkit on %path (%mimetype, %dimensions)', array('%toolkit' => $image->toolkit, '%path' => $image->source, '%mimetype' => $image->info['mime_type'], '%dimensions' => $image->info['width'] . 'x' . $image->info['height']), WATCHDOG_ERROR);
        return FALSE;
    }
    return TRUE;
}

function blurred_background(stdClass $image, $width, $height) {
    $src_w = $image->info['width'];
    $src_h = $image->info['height'];
    $src_image = $image->resource;

    $src_aratio = round($src_w / $src_h, 7);
    $dst_aratio = round($width / $height, 7);
    if ($dst_aratio != $src_aratio) {

        if ($dst_aratio > $src_aratio) {
            // image is a portrait or taller then required
            $tmp_dst_w = $width;
            $tmp_dst_h = round(round($width / $src_w, 7) * $height, 0, PHP_ROUND_HALF_UP) + 1;
            $src_h = $height;
            $src_x = 0;
            $src_y = round(($tmp_dst_h - $height) / 2);
            $dst_x = round(($width - $src_w) / 2, 0, PHP_ROUND_HALF_DOWN);
            $dst_y = 0;
        } else {
            // image is a landscape or wider then required
            $tmp_dst_w = round(round($height / $src_h, 7) * $width, 0, PHP_ROUND_HALF_UP) + 1;
            $tmp_dst_h = $height;
            $src_w = $width;
            $src_x = round(($tmp_dst_w - $width) / 2, 0);
            $src_y = 0;
            $dst_x = 0;
            $dst_y = round(($height - $src_h) / 2, 0, PHP_ROUND_HALF_DOWN);
        }
        // creates empty 'background image' layer
        $blurred_bg = imagecreatetruecolor($tmp_dst_w, $tmp_dst_h);
        // fills empty 'background image' layer with the resized source image
        imagecopyresampled($blurred_bg, $src_image, 0, 0, 0, 0, $tmp_dst_w, $tmp_dst_h, $src_w, $src_h);
        // applies blur filters 'background image' layer
        for ($i = 0; $i < 25; $i++) {
            if ($i % 10 == 0) {//each 10th time apply 'IMG_FILTER_SMOOTH' with 'level of smoothness' set to -7
                imagefilter($blurred_bg, IMG_FILTER_SMOOTH, -7);
            }
            imagefilter($blurred_bg, IMG_FILTER_GAUSSIAN_BLUR);
        }
        // creates empty 'destination image' layer
        $dst_image = imagecreatetruecolor($width, $height);
        // merges 'destination image' layer with blurred 'background image' layer
        imagecopyresampled($dst_image, $blurred_bg, 0, 0, $src_x, $src_y, $width, $height, $width, $height);
        // merges 'destination image' layer with 'source image'
        imagecopyresampled($dst_image, $src_image, $dst_x, $dst_y, 0, 0, $src_w, $src_h, $src_w, $src_h);
        $image->resource = $dst_image;
        $image->info['width'] = $width;
        $image->info['height'] = $height;
        imagedestroy($src_image);
        imagedestroy($blurred_bg);
    }
    return TRUE;
}