Image clip inside selected area

I have a drawing with TIFF images that I need to clip. The problem is
that I want to clip inside the boundry that I create. I'm using
Acad2002. After inserting the image I choose modify, clip, image then
I select the image to clip by picking the image at its border. At the
prompt I press enter to create a clipping boundry using a rectangle
which clips everything outside of the boundry but I need to clip
everything inside the boundry -- is there a way to do this? I have
tried using the polygonal boundry by creating a polygon that treats
the area I want to clip as the outside of the polygon. This sort of
works but is very cumbersome. Any suggestions?

 

Hi,

you can leave your tiff image as is and create a bitonal (monochrome
bitmap in Windows Paint) 1 by 1 pixel (leave the pixel white).

attach the bitonal image in your DWG, scale to the appropriate size,
and clip that bitonal image to the size and shape of the area that you
want to "hide" in the other tiff image

move the clipped bitonal over the desired location on the tiff and use
DRAWORDER to make sure the clipped bitonal stays on top of the tiff

result is you have a blank area on which you can place autoCAD
entities (might take a bit fiddling with the draworder command again)

Op 10 Jan 2004 15:40:33 -0800 schreef (Richard
Mobarak):

 

Your method works, I guess the only way to get the right shape once
it's imported into autocad is to clip the bitmap image. I wish there
were a way to alter the aspect ratio after importing into autocad. One
problem I was having is loosing the text under the bitmap image when I
try to clip it to get the right size. If I clip it before moving it
over the text it's difficult to get the right size. I have a lot of
different paragraph sizes to work with.

 

You could try to set the one pixel in that bitonal bitmap to
transparent in e.g. Paint Shop Pro ( I'm not sure of the required
filetype of the bitmap, don't think that .BMP supports transparent
pixels, but .GIF does (not available here in Belgium - licencing
issues apparently) .TIFF and .PNG might also).

AutoCAD recognizes transparency in bitmaps.

Attach the bitonal to the dwg in AutoCAD, right-click on it and select
Transparency, set to ON. Now you should be able to see right trough
it, and read the underlying text. Scaling and clipping should be
easier now. When OK, set transparency to OFF again.

I haven't tried it myself, so I don't know for sure if this works.


Op 11 Jan 2004 14:25:12 -0800 schreef (Richard
Mobarak):

 

Something else I found in the news group: http://tinyurl.com/2o932

 

That's a neat trick; makes things MUCH easier, thanks for pointing it
out to me!

Op Mon, 12 Jan 2004 20:20:15 -0700 schreef Richard Mobarak

 

which clips everything outside of the boundry but I need to clip
If you have express tools, the Wipeout may do the job, depending on your
situation. Or using the bitmap as a fill in a Super Hatch.