Rust Requires Chilkat v11.7.0+

Add an Image (Logo) Watermark to a PDF

See more PDF Watermark Examples

Demonstrates an image watermark placed in a corner of every page. The image is a PNG or JPEG given either by path ("image.path") or, as here, as base64 in the JSON itself ("image.base64"), which suits a server that keeps its logo in a database rather than on disk. PNG transparency is kept. Giving only a width keeps the aspect ratio, and the units member says those numbers are inches rather than points. Rust

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// The PDF used in this example is available at four_pages.pdf

let pdf = chilkat::Pdf::new();
if pdf.load_file("qa_data/pdf/four_pages.pdf").is_err() {
    println!("{}", pdf.last_error_text());
    return;
}

let json = chilkat::JsonObject::new();
let _ = json.update_string("type", "image");

// A small PNG logo, base64 encoded.  Use "image.path" instead to name a PNG or JPEG file:
//    ignore = json.UpdateString("image.path","logo.png");
let _ = json.update_string("image.base64", "iVBORw0KGgoAAAANSUhEUgAAAGAAAAAgCAYAAADtwH1UAAAApElEQVR42u3a7QmAIBgAYTdpo/ZphhZti6IBylLrlXoO/G3cIeFHSgAAFDKM08rCy8Jzg6Ug8UJ0JF+EDuSXRGgxX8+jufxlTk0nFuCCiF360aidXICMiDP5uQgCXAxQI782ggAHEu7IP4sgQOcBIMA35ItgBQhQEqBmtbX6xl//hAUI3gcIELwTFiD4LEiA4NNQAYLvA+BGzJ0wvIrwLggA8DgbwPbrr8c7+lkAAAAASUVORK5CYII=");

// The size to draw it at.  Give only the width and the height follows the aspect ratio.
let _ = json.update_string("units", "in");
let _ = json.update_number("image.width", "1.5");

// Bottom-right, half an inch in from the page edges.
let _ = json.update_string("position.align", "bottomRight");
let _ = json.update_number("position.margin", "0.5");
let _ = json.update_number("opacity", "0.85");
let _ = json.update_string("id", "logo");

let json_out = chilkat::JsonObject::new();
if pdf.watermark("add", &json, &json_out).is_err() {
    println!("{}", pdf.last_error_text());
    return;
}

println!("id: {} pages: {}", json_out.string_of("id").unwrap_or_default(), json_out.string_of("pages").unwrap_or_default());

if pdf.write_file("qa_output/four_pages_logo.pdf").is_err() {
    println!("{}", pdf.last_error_text());
    return;
}

// Sample output:

// id: logo pages: 1-4