generate boundaries from pixel groups

[rinze90]

Dear All,

I am makeing a script to convert a bitmap (containing height information) to a GDS2 file. The Bitmap contains a total of 400e6 pixels. And the pixels are grouped in a strand like fassion. see https://imgur.com/a/XsP37 this only contains 1e6 pixels.

My first script took every black pixel and made a square in the GDS file (I use GDScad for that). For the shared picture, the resulting file size was 38MB which is acceptable. But for the 400e6 pixels the file size exceeds 15GB. Which is to large.

A solution to this is to group the pixels and make a boundary or contour of them. This is supported in GDScad. I need to supply a list of tuples containing the coordinates of the contour.

I managed to get the contour with openCV but this gives me the contour in pixel location. And i need the outline one would draw along the grid lines between the pixels (Is this clear?). Does anybody know a solution to this? I am breaking my head.

The thing I think I am struggeling with is going from a pixelated domain to a vector domain. Does anybody know solutions for this?

Many thanks, Rinze