This service returns a piece of imagery as a JPG or PNG, cut from the seamless orthomosaic. The same imagery you can access via GetOrthoImageTiles is used to create the returned image. ExtractOrthoImages saves you the work of making multiple API calls to GetOrthoImageTiles for individual tiles, stitching them together into a large bitmap, and cropping it to your spec. With a single API call you can get back a static map image matching your specification.

Note: the maximum size for a returned image is 67,108,864 pixels or the equivalent of 1,024 individual tiles. If your request results in an image exceeding these limits, an error is returned.

You can use the OrthoCoverage service to determine where ortho coverage exists. This allows you to know if a call to ExtractOrthoImages will succeed or fail based on image availability.

USE CASES

All use cases will ensure that imagery will not exceed either 67,108,864 pixels (e.g., 4096 x 16384) or 1,024 tiles.

1. xcoordinate + ycoordinate + zoom + width + height: This is the most common use of the service. Here you pass in a coordinate where the image will be centered and a standard zoom level. You also pass in the width and height in Pixels of the image you want returned.

2. wkt: Here you pass a polygon in the WKT parameter that you want covered by the returned image. The service will calculate the deepest zoom level that covers the polygon with less than the maximum number of tiles (1,024).  The resulting bitmap will be fit to the minimum bounding rectangle (or MBR) for the polygon that was passed in the WKT parameter. Note that the Pixel dimensions of the resulting image are also determined by the service and cannot be specified.

3. wkt + zoom: This is very similar to the previous case, but instead of the system selecting the optimal Zoom level, you specify it with the Zoom parameter. This allows you to scale the image (shown below under examples).

Output Tile Specifications:

• 8-bit depth

• 3-band (RGB or NIR)

• 7.5 or 20 cm centimeter resolution (layer dependent)

• Image format: JPEG or PNG

• Blue Sky and Gray Sky imagery available

• Maximum size: 67,108,864 pixels or 1,024 tiles

Drawing Element Parameters

• drawingPolygon - The polygon to be draw in WKT format (The EPSG has to be the same EPSG that is in the head of the petition)

• lineWidth - The width for the polygon’s exterior line

• outlineColor - The color for the polygon’s exterior line (RGB format)

• fillColor - The color for the polygon’s fill

• drawingPointList - An object list of point(s) and associated label(s)

  • point - The point coordinates in latitude and longitude (decimal degrees).

  • label - The custom label for each point.

• fontSize - Font point size for labels

• fontColor - Font color for labels (RGB color)

• fontType - Font typeface (Options: Monospaced, SansSerif or Serif)
  
  

JSON format:

REST URL:

https://api.gic.org/images/ExtractOrthoImages/bluesky-high-europe?ycoordinate=50.894916&xcoordinate=4.340991&zoom=17&width=600&height=400&EPSG=4326&token={token}

Image:

REST URL:

https://api.gic.org/images/ExtractOrthoImages?layer=bluesky-ultra&epsg=4326&wkt=POLYGON((-76.580924 39.263944, -76.578685 39.263938, -76.578682 39.262136, -76.580924 39.262134, -76.580924 39.263944))&format=image/png&AOI=us-md-baltimore-2021&renderingRule=nir&token={token}

Image:

REST URL:

https://api.gic.org/images/ExtractOrthoImages?zoom=19&layer=bluesky-ultra-oceania&epsg=4326&wkt=POLYGON ((144.972431 -37.830084, 144.973944 -37.829724, 144.974269 -37.830955, 144.973075 -37.831252, 144.972431 -37.830084))&startDate=2021-02-09T00:00:01+00:00&endDate=2021-03-16T23:59:59+00:00&token={token}

Image:

See Also

• Authentication Token Services

• OrthoCoverage Service

External Resources

• EPSG Codes: https://en.wikipedia.org/wiki/EPSG_Geodetic_Parameter_Dataset

• Well-known text (wkt): https://en.wikipedia.org/wiki/Well-known_text_representation_of_geometry

• Decimal Degrees: https://en.wikipedia.org/wiki/Decimal_degrees