Posted by rherr on May 24, 2015; 7:52pm
URL: https://forum.librecad.org/Scaling-imported-images-tp5711385p5711555.html

Armin,
Thanks for your prompt reply.
Alas, I don't think I can change the scale of the original image.  It was generated from the gEDA PCB printed circuit board editor as a PNG file.  I had tried several adjustments to the PCB PNG output parameters, such as changing the Pixels Per inch (PPI) option, with virtually the same results in LCAD.  As I said, I even tried importing the PNG file into Inkscape and converting to a DXF file, as the LCAD manual suggests, with the fatal crash results in LCAD when I tried to import it.

I did try reducing the PCB PPI option, with the results you warn about.  It looked very coarse, but still the large size.

I cannot scale the original PCB drawing, since it is obvious it must be the size of the circuit board in the real world.  To maintain two scales of the same object in PCB is not acceptable.  The whole idea of CAD/EDA is to make the processes easier and less error-prone.  To that end, I wanted to use the PCB image output for the base LCAD drawing in order to keep the accuracy and not re-draw the image.

After posting my message, I ended up importing my image into the gEDA gschem schematic capture program, which has limited mechanical drawing capabilities.  That is why I wanted to use LCAD for this process.  It looks like I can continue to use LCAD for drawings not needing an image import, while continuing to use gschem for drawings I need to import an image for.

Note to the LCAD devs:  It might be a good thing to look into the gschem image import code.  The version of gschem I am using, 1.8.2, allows scaling the image prior to instantiation by dragging the opposite corner, as well as rescaling the instantiated image, by dragging a corner.  It keeps the x-y ratio when doing so.  It worked great.

Thanks again,
Girvin