Using the Image Viewer

This page described how to use and control the Image Viewer



The Image view is primarily controlled by the mouse. To pan in the image, double click on the new image center. To zoom in and out, use the middle mouse button. Menu bar items reset the Pan/Zoom to the original configuration. Right clicking opens the context menus.


The appearance of the Image Viewer is set through its control panel as well as any additional Views (such as Colormap or Histogram) that are linked to the viewer. To activate the basic settings, click on the Image Settings (or select from the pop-up menu after right clicking.

Example of the Image Viewer

The 'Image Settings' have a tabbed navigation view consisting of controls for the different components of the Image.


This controls the parameters and visibility of the overlying coordinates grid. In many cases, these controls have both 'Settings' as well as a 'color-picker' menu which determines the colors of the different components. A 'color picker' is shown for the 'Axes/Border' component below.

Example of using the image viewer




Whether the grid appear (to suppress the grid and coordinate axes, uncheck the Coordinate System checkbox), whether the coordinates of the cursor update with mouse motion (Cursor checkbox) and what coordinate system is used for the overlay.


This determines grid lines, their opacity and relative spacing. The color menu will independently control the grid colors.


This determines where the axes and boundary appear in the image. Internal axes will be projected over the image in the coordinate frame. The image can be transposed as desired by changing what is plotted on the x and y axis.


This controls how and where the axes are labeled including the precision of the labels that is shown.


This controls the size, shape and opacity of tick marks along the axes.


The contour tab controls the image contour overlays. CARTA uses a notion of contour sets which are generated using the Contour Sets tab. Once generated, the properties of individual contour sets are controlled by tabs that appear on the left side of the panel. The image below show the generation of a contour set for the image (here named Example Contours). Contours are selected to show 10 levels between 0 and 100. Contour sets can be deleted by selecting their name from the drop-down menu and pressing Delete Contour Set.

Using the contour tool

The properties of the group of contours or individual contours can be changed in the Example Contours tab. Here, one of the contours has been selected and the color changed to yellow. Note that the values of the contours can be changed by double clicking on the numerical value in the list and edited.

Controlling contour properties

Image Stack:

These are the controls for compositing multiple images of the same coordinate grid. The stack controls where and whether different image layers appear in the visualization. At present, the Image Stack is still under development.


This panel controls the properties of the regions defined on the image. At present, the Region functionality is still under development.