proj4 = '+proj=somerc +lat_0=46.9524055555556 +lon_0=7.43958333333333 +k_0=1 +x_0=0 +y_0=0 +ellps=bessel +towgs84=660.077,13.551,369.344,2.484,1.783,2.939,5.66 +units=m +no_defs +type=crs'
m = Map(256,256,proj4)
lyr = Layer('Name',proj4)