How to create a Color Mask and set multiple colors transparent

	Product(s):	Bentley Descartes for MicroStation
	Version(s):	08.11.09.601
	Environment:	N\A
	Area:	Tools
	Subarea:	Edit

Steps to create a Color Mask and set multiple colors in a raster image transparent in Raster Manager

Background

A Color Mask can be used when working with Color and Grayscale raster images when using tools in Descartes like the Vectorization tool, which is used to convert raster data to vector data.

A color mask lets you handle any image with more than two colors exactly as if it was a two-color image. A color mask cannot be defined for two-color images (Monochrome), as they already have only a foreground color and a background color. All tools used for image editing or vectorization, normally work with binary (two color) images only. Because of the color mask feature, these tools can now be used with images that have more than two colors. For a given image, you can define an unlimited number of color masks to be saved in the same color mask file.

Steps to Accomplish

Create a color mask in Descartes.

1. Go to Raster Manager Settings > Tools > Color Mask.

2. Click on the 3rd tool, the color mask dialog.

3. Click on untitled and right mouse, then New Mask.

4. Give the mask an appropriate name.

5. Highlight the mask name, right mouse click > Add colors.

6. In the Add to mask tool settings, select the Area option (the method to select the colors) and make sure your mask name is listed below. Check on highlight to show the colors selected in the image.

7. Select the colors by clicking on the image. Notice they will highlight in red. Once all of the colors are selected for the mask, go back to the Color Mask dialog and select File > Save.

8. Now go to Raster Manager Utilities > Descartes Attachment. In the transparency tab, select RM Define and click Remove and then select the color mask you just created and click Insert. By default the transparency will be set to 100%. Close this dialog.

9. Make sure that the transparent toggle is turned on in Raster Manager > Settings > Attachment > Color tab, refresh the view and the image should now have transparency.

Note 1: Raster Manager will honor transparencies set in Descartes, but the raster manager user will not be able to modify the color mask. This can only be done using Descartes.

Note 2: Raster Manager can only make one color transparent. This is accomplished through the Raster Manager > Settings > Attachment Settings > Color tab. Select the color to be made transparent and the percentage of transparency.

Set one color in the raster image transparent

1.) Highlight your raster image name

2.) Click on the Transparency button. This will bring up the Select Transparency box

3.) Click on the eyedropper and hold your mouse button down and drag it over the area you want to be transparency. It will set the transparency color.

The area that matches that color will then be transparent. If a color is not transparent then it may be that the area that you want to be transparent is made up of different colors that are close, but not the same color. In this case they colors will have to be added to the color mask.

Original Author:

Frank McAllister

Created by Felix James
When: Mon, Nov 2 2015 9:02 AM
Last revision by Pascal Cloutier
When: Thu, Mar 19 2020 10:11 AM
Revisions: 2
Comments: 0

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