| <script> |
| function load_multipart_image(src) { |
| return new Promise((resolve, reject) => { |
| const img = document.createElement('img'); |
| img.addEventListener('load', () => resolve(img)); |
| img.addEventListener('error', (e) => reject(new DOMException('load failed', 'NetworkError'))); |
| img.src = src; |
| }); |
| } |
| |
| function get_image_data(img) { |
| const canvas = document.createElement('canvas'); |
| const context = canvas.getContext('2d'); |
| context.drawImage(img, 0, 0); |
| // When |img.src| is cross origin, this should throw a SecurityError. |
| const imageData = context.getImageData(0, 0, 1, 1); |
| return imageData; |
| } |
| </script> |