Drawing
A plugin for drawing canvas forms (overlaid graphics).
Plugin Type: Local
Drawing
is a local plugin, which means it is associated with a
channel. An instance can be opened for each channel.
Usage
This plugin can be used to draw many different shapes on the image display. When it is in “draw” mode, select a shape from the drop-down menu, adjust the shape’s parameters (if needed), and draw on the image by using left mouse button. You can choose to draw in pixel or WCS space.
To move or edit an existing shape, set the plugin on “edit” or “move” mode, respectively.
To save the drawn shape(s) as mask image, click the “Create Mask” button
and you will see a new mask image created in Ginga. Then, use SaveImage
plugin to save it out as single-extension FITS. Note that the mask will
take the size of the displayed image. Therefore, to create masks for
different image dimensions, you need to repeat the steps multiple times.
Shapes drawn on the canvas can be loaded and/or saved in astropy-regions (compatible with DS9 regions) format. To use that you need to have installed the astropy-regions package. Simply draw objects on the canvas, with coords as “data” (pixel) or “wcs”. Note that not all Ginga canvas objects can be converted to regions shapes and some attributes may not be saved, may be ignored or may cause errors trying to load the regions shapes in other software.