Background Image

Below are the functions for editing the background image.

A background image means an imported image file. An imported aerial photograph of the area to be analyzed can be used to edit the geographic data and grid information.

The following types of image files can be imported for the iRIC background image:

  • jpeg
  • png
  • tiff

When a geographic reference file (refer to the iRIC Related File Manual) is in the same folder as an image file, the file is automatically read and used to adjust the positions.

When there is no geographic reference file, the position of the imported background image is automatically adjusted such that it is displayed in the same area as the already imported geographic data and grid. After that, the user can manually adjust the image.

Functions related to the background image are available only when the Pre-processor is active. The function of each menu item is explained here.

[Import] (I)

Description: Imports the background image. A background image can be imported by either of the following operations:

Menu bar: [File] (F) –> [Import] (I) –> Background image (B)

Menu bar: [Import] (I) –> Background image (B)

Then, the [Open Image File] dialog (Figure 346) will open. Select the image data file you want to import and click on [OK].

Then, the background image is imported and the item is added to [Object Browser]. Figure 347 shows an example of the iRIC display after a background image has been imported.

../_images/bg_open_image_file_dialog.png

Figure 346 [Open Image File] dialog

../_images/iric_after_bg_import.png

Figure 347 Example of the iRIC display after a background image has been imported

Georeference

Description: Adjusts the background image locations by specifying corresponding points (GCPs).

In [Object Browser], select the background image whose position you want to adjust. Select [Georeference] from right-clicking menu to open [Georeference] dialog. (Figure 348).

../_images/bg_image_georeference_dialog.png

Figure 348 [Georeference] dialog

Click on the image in the [Georeference] dialog to add a point.

Then, click on the [Pre-processor Window] to add a corresponding point.

Repeat clicking to add as many points as you want. Figure 349 shows an example of the iRIC display after five pairs of points have been selected.

../_images/bg_image_georeference_dialog_example.png

Figure 349 Example of the iRIC display after specifying points for georeference

By clicking on [Apply], you can see a preview of georeference.

When you click on [OK], the image position will be modified and dialog will be closed.

You can revert the image position by clicking on [Cancel].

Figure 350 shows an example of the iRIC display after [Apply] is clicked.

../_images/bg_image_georeference_dialog_apply.png

Figure 350 Example of the iRIC display after applying georeference

You can modify the position of points by mouse operation, or by editing coordinate values in the table.

You can delete selected points from right-clicking menu.

Adjusting Positions

Description: Adjusts the background image locations.

In [Object Browser], select the background image whose position you want to adjust. Perform the procedure explained in Table 27 on the canvas to adjust the position of the background image.

Table 27 Procedure for adjusting the position of the background image
Adjusting operation Action Cursor
Rotate Left drag cursor_rotate
Zoom in/out Drag or scroll up/down the mouse wheel cursor_zoom
Translate Right drag cursor_translate

To fix the position of the background image, select icon_pin_free in the Operation Toolbar (the icon changes to icon_pin_fix). When the position of the background image is at a fixed point, the adjusting operation is disabled, even if [Background Image] is selected in [Object Browser].

Click again to make the background image movable.

By selecting [Property] from right-clicking menu, you can open [Background Image Position] dialog (Figure 351) and specify the position by editing values.

../_images/bg_image_position_dialog.png

Figure 351 The [Background Image Position] dialog