Apply transparent colors in images

Many images have been cut from polygons, but in doing so, it has not been set a transparent color to the background and that’s why an uncomfortable black color appears. Or in other cases, we wish not be visible a range of colors; let’s see how to do it:

With gvSIG.

I’m using stable version 1.9, which download madness ended finally in twenty minutes. By the way, see the locator in the left pane, just as Qgis style.

To add transparency to the image becomes the following:

Right click on the layer in the side frame, chose the raster properties.
Then, in the displayed panel, choose the transparency tab, and activate the checkbox
It is necessary to know the rgb color combinations, in this case I wish to remove the black, the combination is easy: 0,0,0. So, we add it, and then the black becomes transparent.
If you don’t know the rgb code, you can select it from the screen with some free programs which are there, as Visual Color Picker, for example.

To save changes press OK

You can add more colors, although it wouldn’t be a wrong idea that for future versions, gvSIG would add a color picker that captures a color by clicking on the screen.

With Microstation V8

In the raster manager, select the image with a right click and choose attachment settings.