Raster Manager supports some basic raster editing, however only Bentley Descartes provides advanced raster editing. All editing operations that change the pixel values are not persistent - meaning that the original pixel values are not modified. To permanently modify the pixels, Bentley Descartes would be required.
Raster Manager provides these basic functions for positioning an image:
Most of these functions are similar to those found in Bentley Descartes except that Descartes provides a few additional options. Most notably is the Helmert method for the Warp transformation and added flexibility regarding the axis selection for the Mirror transformation. For more information, please see Bentley Descartes - Raster Transformation.
With Raster Manager it is possible to clip an image so that only the area inside, or outside, the specified clip region is visible.
The following describes how clipping can be used to control the display of those pixels that represent a body of water. The first exercise is to define the clipping area. This can be done by drawing a shape around the water as shown.
Once the clipping area has been defined, the desired clipping mode must be selected in the Tool Settings dialog. For example, to only display those pixels inside the shape drawn in the previous step, set the mode to Clip Boundary.
On the contrary, if the pixels inside the boundary should be hidden, then the Clip Mask clipping mode should be used.
Raster Manager provides several controls for modifying the appearance of attached images.
Where images appear dull, or lack in contrast, you can change their contrast and brightness display settings. Additionally, you can change the Display Gamma setting. Changing any of these settings does not alter the original image. Display settings may be different for individual images and they are saved with the DGN file. Changing the Contrast and Brightness may only be carried out on one image file at a time, while the Display Gamma setting can be applied to a number of selected image files simultaneously.
When working with multiple, overlapping or otherwise complex designs, a tint can be applied to coloured images. The feature can be used to assist with visualization.
For colored images, the Transparency setting is used to set a transparent color for the raster reference. The selected color in the raster image then becomes transparent, when the Transparent setting is enabled.
For monochrome images, the Background Color setting is used to set the background color of the raster file.
The chosen transparency color also is used as a fill color when clipping raster images.
Bentley Descartes - Raster Editing