iiif_get_thumbnail()

Description

Get thumbnail information for the specified resource id ready for IIIF JSON encoding

Parameters

ColumnTypeDefaultDescription
$resourceid integer Resource ID

Return

array

Location

include/iiif_functions.php lines 1291 to 1336

Definition

 
function iiif_get_thumbnail($resourceid)
{
    global $rootimageurl;

    $img_path = get_resource_path($resourceid, true, 'thm', false);
    if (!file_exists($img_path)) {
        // If configured, try and use a preview from a related resource
        $resdata = get_resource_data($resourceid);
        $pullresource = related_resource_pull($resdata);
        if ($pullresource !== false) {
            $resourceid = $pullresource["ref"];
            $img_path = get_resource_path($resourceid, true, "thm", false);
        }
    }

    if (!file_exists($img_path)) {
        return false;
    }

    $thumbnail = array();
    $thumbnail["@id"] = $rootimageurl . $resourceid . "/full/thm/0/default.jpg";
    $thumbnail["@type"] = "dctypes:Image";

    // Get the size of the images
    $GLOBALS["use_error_exception"] = true;
    try {
        list($tw,$th) = getimagesize($img_path);
        $thumbnail["height"] = (int) $th;
        $thumbnail["width"] = (int) $tw;
    } catch (Exception $e) {
        $returned_error = $e->getMessage();
        debug("getThumbnail: Unable to get image size for file: $img_path  -  $returned_error");
        // Use defaults
        $thumbnail["height"] = 150;
        $thumbnail["width"] = 150;
    }
    unset($GLOBALS["use_error_exception"]);

    $thumbnail["format"] = "image/jpeg";

    $thumbnail["service"] = array();
    $thumbnail["service"]["@context"] = "http://iiif.io/api/image/2/context.json";
    $thumbnail["service"]["@id"] = $rootimageurl . $resourceid;
    $thumbnail["service"]["profile"] = "http://iiif.io/api/image/2/level1.json";
    return $thumbnail;
}

This article was last updated 22nd May 2025 11:35 Europe/London time based on the source file dated 4th April 2025 15:35 Europe/London time.