US 12,260,664 B2
Method for generating regions of interest based on data extracted from navigational charts
Adrian Mai, San Diego, CA (US); and Douglas Seth Lange, San Diego, CA (US)
Assigned to United States of America as represented by the Secretary of the Navy, Washington, DC (US)
Filed by United States of America as represented by the Secretary of the Navy, San Diego, CA (US)
Filed on Oct. 4, 2022, as Appl. No. 17/960,000.
Prior Publication US 2024/0112489 A1, Apr. 4, 2024
Int. Cl. G06V 30/422 (2022.01); G06V 30/146 (2022.01); G06V 30/18 (2022.01); G06V 30/19 (2022.01)
CPC G06V 30/422 (2022.01) [G06V 30/147 (2022.01); G06V 30/1801 (2022.01); G06V 30/18105 (2022.01); G06V 30/19013 (2022.01); G06V 30/19107 (2022.01)] 20 Claims
OG exemplary drawing
 
1. A method for extracting data from a navigational chart comprising the following steps:
determining if the navigational chart is a single-layer, raster navigational chart (RNC) or an electronic navigational chart (ENC);
if the navigational chart is a single-layer RNC,
using a computer vision algorithm to extract color, text and symbol data from the single-layer RNC,
storing the color, text, and symbol data in a database, and
building an RNC data vector based solely on the color, text, and symbol data of the single-layer RNC, wherein the RNC data vector identifies geographical features shown in the single-layer RNC and a location of the geographical features' corresponding pixels in the single-layer RNC;
if the navigational chart is an ENC,
identifying an ENC data vector, wherein the ENC data vector identifies geographical features shown in the ENC and a location of the geographical features' corresponding pixels in the ENC; and
drawing a region of interest on the navigational chart based on user input and the ENC or RNC data vector, wherein a perimeter of the region of interest is georeferenced with latitude and longitude information.