1. Preparing your image for AutoCAD
You can start off with an drawing or sketch done in Autocad itself and exported out in raster format or create directly in a raster package (ie a "paint" program) like PaintshopPro, PhotoShop, Illustrator or good old MS Paint. Of course you might just have found something on the net or taken a photo with a digital camera. Finally you might have made a hand drawing on piece of paper or found a picture in a book which means you will have to scan it on the relatively simple $300 scanner you should keep around anyway for scanning portions of maps or old drawings that have never been converted to CAD.
Once you have your image in a raster file format you will need to use one of the paint packages to like Photoshop to modify it to achieve transparency in AutoCAD. AutoCAD can take most image formats but if you want transparency it will have to be a bi-tonal image (two tone / black and white). These types of images are often bitmaps (BMPs)but you can produce bi-tonal TIF's and other formats that work as well but BMP's will often do just fine.
2. Converting An Image Into A Bi-Tonal Bitmap
In the illustration below, I show that you can even prepare one of these images in Microsoft Paint which is included with Windows.
Using Paint, just save your image with the Save as type: set to Monochrome Bitmap (*.bmp, *dib).
In more expensive packages, you have control over the pixelation and dithering effect so with some trial and error runs you can find the cleanest look on your final AutoCAD prints, but you have to be careful because it is very easy to create images that are too large to be practical for use.
3. Working with your image in AutoCAD
Using Image Manager to Reference your image
In AutoCAD, you can use the Image Manager to Attach your bi-tonal bitmap in the same fashion as you would Attach an Xref. You can type "im" (alias for )on the command line to bring up the dialogue box illustrated below.
Once you bring in your image, you may have to work with the Scale of it by using the Scale command or Grips to Stretch it out. On Civil Survey drawings, I use this trick a lot and combine it with the Scale Reference option to scale the image based upon a known distance on the image.
The image will not be transparent by default so you should see something like that illustrated to the right. If you don't have a lot of black around your image, something went wrong when you converted it to a bi-tonal image and you will probably have to go back and try it again in your image editing program (like PaintShoppro or Photoshop).
Activating Image Transparency And Deactivating The Image Frame
Illustrated to the below, I show how you make the bi-tonal bitmap transparent. You can use the Transparency button on the Reference toolbar or select the Image's frame, right mouse click, select Image off the object specific pop-up menu and cascade over to Transparency.
Once you type "On" in response to the "Transparency" command, your image should become transparent everywhere except where pixels exist - see illustration.
The last thing you will probably want to do just before printing, is turn "Off" the Image Frame. To do this, you can use the Image Frame button on the Reference toolbar, use the object specific pop-up menu or simply type "ImageFrame".
Final Results
Illustrated below is what the print will look like. These types of images are pure black unless you use a Color that gets screened when you print. A grayscale does appear in some bi-tonal images because of pixel density; i.e., more pixels closer together appear black and fewer pixels spread farther appear can appear gray.
By using other Image tools, like Image Clip, you can begin combining raster and vector work in AutoCAD like the artist you truly are.
Now, let's see how good you have become. Look at the first image in this column and try to figure out how I got the tree to go behind the building. There are several possible answers but I didn't use Image Clip.
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