In this exercise you learn about making an image color transparent.
You can specify one transparent color in each image. Then all parts of the image with that color (or shade of gray) can be made opaque or transparent. This is useful if you want to see information displayed behind the image. In bitonal images, the transparent color is always the background color of the image.
Related Exercises
Before doing this exercise, ensure that AutoCAD Raster Design toolset options are set as described in the exercise Exercise A1: Setting AutoCAD Raster Design Toolset Options.
Exercise
- In the \Tutorial5 folder, open the drawing file Map_08.dwg.
- Select the image frame of the USGS quad sheet.
- Right-click and select
Properties to display the
Properties window.
The Properties window contains a long table; use the vertical slider to scroll up and down. Note that near the bottom are two separate tabs labeled Misc.
Specify the background transparency properties for the image
- On the upper
Misc tab, click
Background Transparency and change the value to
Yes.
The background transparency properties appear near the end of the properties list under Misc.
- On the lower Misc tab, click Transparent Color, then click the pick button [...] to display the Transparent Color dialog box.
- Click
Select, click anywhere in the white border area of the USGS image, then click
OK.
Note that the white border becomes transparent, along with any white areas within the map.
- Close the Properties window.
- Close the drawing without saving changes.