Subject: NAC- cad design question

[SJ]

Steve
My understanding is that Cad type files are based on mathematical
expressions. A line is represented by a vector . . a starting point with a
known distance and direction.

The reason for this is that you can enlarge the drawing to any size you want
and you lose no clarity. If a line is expressed as 2 units starting at x,y,z
and at 270 degrees, and you enlarge the pix by 2x, the line becomes 4 units,
270 deg, 2x, 2y, 2z etc etc etc.

Once you convert the cad file into a jpg file, you lose all those math
expressions. The jpg format only understands pixel positions, colors, and
how many repetitions(compression) of that before a change is made. When you
enlarge a jpg pix . . . .you dont get more pixels added to make the pix
sharper. The original pixels just get enlarged.

You cannot convert pixel locations and colors(jpg) back into mathematical
expressions(CAD).

I think thats how it works, more or less.

SJ



> From: Warren Parrington <WP at mcleodrusseluk.com>
> Hello Ste,
>
> Im not sure what you actually want to do?
>
> Warren.
>
>
> Anyone now of a jpg, pdf to dxf,dwg or any cad type file conversion
program.
> I've found programs that convert into jpegs but the reverse.
>
> Thanks in advance.
>
> Steve