Image Overlays

Image Overlays allow imported images to be shown on the 2D and 3D map views, either in front of or behind the map contour layer. Any number of images can be added to the project, and the relative order and transparency of each image can be individually adjusted.

The image above shows the 3D View of a map project. Depth information has been used to generate the model in the usual way, and a side-scan mosaic has been overlaid on the model. The opacity of the map layer has been reduced so that the mosaic image underneath can be seen, with the depth colours still visible.

Image Overlays Edit Pane

Images are added to projects via the Image Overlays edit pane, in the Project Properties Window.

(1, 2) Background and Foreground Images

Images can be added to the map project as either foreground or background images. Foreground images show in front of the map contour layer, whilst background images show behind the map contour layer. The map contour layer is the name given to the depth colour and contour line display (see Map Opacity, below). The opacity of an image can be adjusted using the Opacity slider (5) shown in the image row.

(3) Map Opacity

The transparency of the map contour layer can be adjusted using the Map Opacity slider. Only the coloured background (vector or raster) is affected by changes in map opacity; the contour lines always remain at 100% opacity. Reducing the map opacity to zero is the equivalent of selecting the transparent background palette.

Note that map opacity is persisted and that opacity values will be used when the map is exported.

(4) Available Images

The Available Images list shows a list of all images in the current workspace that can be added to the current project as an image overlay. See Background Images for information on how to import and calibrate images. Images that have already been added to the current project are not shown in the available images list. Images can be imported using the New button (6), which starts the standard background image import process.

Adding an image to the project

An image can be added to the project image from the available image list to the project by:

·Dragging the image to the foreground or background images list.

·Clicking the Add (+) button (1) on the image row within the available images list.

·Right-clicking the image and selecting either Add Image to Project Background or Add Image to Project Foreground from the context menu.

Image ordering

The relative ordering of images within the project can be adjusted by dragging the image up or down within the foreground or background image list. The lower the image is in the list, the further forward it is displayed.

Removing images from the project

Images can be removed from the project by:

·Clicking the Remove button in the image row (circled).

·Dragging the image back to the Available Images list.

·Selecting Remove Image From Project from the image context-menu.

Notes on displaying images in the 3D view

Images that are overlaid onto a 3D model are restricted to a maximum size, with images over this size being reduced in resolution. If images appear to be at a lower resolution when viewed in 3D, try generating a smaller subsection of the map.