TVMask plugin

Display masks from file (non-interative mode) on an image.

Plugin Type: Local

TVMask is a local plugin, which means it is associated with a channel. An instance can be opened for each channel.


This plugin allows non-interactive display of mask by reading in a FITS file, where non-zero is assumed to be masked data.

To display different masks (e.g., some masked as green and some as pink, as shown above):

  1. Select green from the drop-down menu. Alternately, enter desired alpha value.

  2. Using “Load Mask” button, load the relevant FITS file.

  3. Repeat (1) but now select pink from the drop-down menu.

  4. Repeat (2) but choose another FITS file.

  5. To display a third mask as pink too, repeat (4) without changing the drop-down menu.

Selecting an entry (or multiple entries) from the table listing will highlight the mask(s) on the image. The highlight uses a pre-defined color and alpha (customizable below).

You can also highlight all the masks within a region both on the image and the table listing by drawing a rectangle on the image while this plugin is active.

Pressing the “Hide” button will hide the masks but does not clear the plugin’s memory; That is, when you press “Show”, the same masks will reappear on the same image. However, pressing “Forget” will clear the masks both from display and memory; That is, you will need to reload your file(s) to recreate the masks.

To redraw the same masks with different color or alpha, press “Forget” and repeat the steps above, as necessary.

If images of very different pointings/dimensions are displayed in the same channel, masks that belong to one image but fall outside another will not appear in the latter.

To create a mask that this plugin can read, one can use results from the Drawing plugin (press “Create Mask” after drawing and save the mask using SaveImage), in addition to creating a FITS file by hand using, etc.

Used together with TVMark, you can overlay both point sources and masked regions in Ginga.

It is customizable using ~/.ginga/plugin_TVMask.cfg, where ~ is your HOME directory:

# TVMask plugin preferences file
# Place this in file under ~/.ginga with the name "plugin_TVMask.cfg"

# Mask color -- Any color name accepted by Ginga
maskcolor = 'green'

# Mask alpha (transparency) -- 0=transparent, 1=opaque
maskalpha = 0.5

# Highlighted mask color and alpha
hlcolor = 'white'
hlalpha = 1.0