MathGroup Archive 2010

[Date Index] [Thread Index] [Author Index]

Search the Archive

overimpose graphics on an imported image


hi people,
I wonder if it is just me being dumb, but I'm unable to perform what I
thought was a very simple operation:

having imported an image of (Lx,Ly) pixels, draw above it an empty
rectangle at coordinates (x0,y0) (x1,y1) (say, lower left and upper
right corners).

Say for example that I want to overimpose on image i1 a rectangle
covering a 10% portion, if I use this:

ImageCompose[i1, Graphics[Rectangle[{0, 0}, {0.1*Lx, 0.1*Ly}]]]

I have (apart from a filled rectangle instead of empty, but I can deal
with it later)
a huge rectangle covering all of it!
How these coordinates interact?

Thanks for any help...


Alessandro Magni


  • Prev by Date: Re: Wrapping Begin["Context`"], ..., End[] into a function
  • Next by Date: Re: List to Expression
  • Previous by thread: Re: Wrapping Begin["Context`"], ..., End[] into a function
  • Next by thread: Re: overimpose graphics on an imported image