transparency - raster over raster

[Anonymous]

I've seen similar posts about making solid hatching transparent, either by
changing plot style tables or using 3rd party software, but I need to make
one raster image transparent over the top of another. Example, have raster
image of new building and want to lay it over an existing aerial image so
that the existing buildings, roads, etc, can still be seen under the new
building image. Is 3rd party software the only route?

[Anonymous]

I use Photoshop to convert an image to BITMAP mode, which
reduces the pixels to black. In Autocad this image can have
TRANSPARENCY turned on with Properties and the image
will float over another, and will print with the colour assigned
by object or layer. (I do not have RasterDesign!)
Rod Dunphy

slarson wrote in message
news:6BC348B2BAA1BD127668797EF858DFDD@in.WebX.maYIadrTaRb...
> I've seen similar posts about making solid hatching transparent, either by
> changing plot style tables or using 3rd party software, but I need to make
> one raster image transparent over the top of another. Example, have
raster
> image of new building and want to lay it over an existing aerial image so
> that the existing buildings, roads, etc, can still be seen under the new
> building image. Is 3rd party software the only route?
>
>


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[twikvera]

Yeah 3rd party software will be the only medium

[ChicagoLooper]

It can be done and very easily. Even without 3rd party software, it can be done. You don't need Raster Design either. Put the raster on its very own layer, e.g. C-IMAGE-RASTER. Then simply control the transparency of the image from the LAYER PROPERTIES MANAGER. In the Layer property manager, go to the transparency column in the layer that hosts the image then click on 0 and change the value (the default is 0=no transparency). The transparency range is 0 to 90. Increase the number to increase the transparency. Hint: 50 is a good starting point for transparency. Then increase or decrease as desired. 

Make sure your 'display order' has the transparent image in 'front' and the underlying image in "back.' Finally, when you go to print check the box 'Plot transparency' to get the see-through effect.

 You can also do this with colored hatch. Even if the hatch is solid you can make it transparent in order to see what's underneath.