Hi martin181818
I don't think you can specify that on the camera node itself, but something like
colormap = pipeline.create(dai.node.ImageManip)
colormap.initialConfig.setCropRect(0, 0, 1, 0.5)
colormap.initialConfig.setResizeThumbnail(300, 300)
could work. Essentially passing the preview through the imagemanip node.
Hope this helps,
Jaka