You can load an image from a file by the menu item File ▹ Load Image or via the corresponding button of the tool bar. To acquire images from a camera, you can also use the Snap and Live buttons in the tool bar.
If you have saved your camera parameters before, you can load them by the menu item File ▹ Load Camera Parameters to use them for a calibration.
If you have saved the settings of a former Measure Assistant session, you can load them again by the menu item File ▹ Load Assistant Settings or via the corresponding button of the tool bar.
You can save the current settings of a Measure Assistant using the menu item File ▹ Save Current Assistant Settings or the corresponding button of the tool bar. Then you can load them again in a later session.
When closing the Measure Assistant dialog with the menu item File ▹ Close Dialog or the X in the top right corner of the window, the current settings are stored for the duration of the current HDevelop session. As long as you do not exit HDevelop, you can again open the Measure Assistant with the same settings. In contrast to this, when you exit the Measure Assistant, the settings are lost also for the current HDevelop session.
When you exit the Measure Assistant with the menu item File ▹ Exit Assistant, the assistant's dialog is closed and the current settings are lost unless you have stored them via the menu item File ▹ Save Current Assistant Settings. If you want to close the dialog but keep its settings for the current HDevelop session, you should use the menu item Close Dialog instead.