ffmpeg – How do I upscale a 720×576 [SAR 16:15 DAR 4:3] video to crop out black bars?

I have a movie from one of my DVDs looking like the following after having imported it and muxed it to a .mkv container:
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`ffprobe“ provides me with the following information:
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I recently imported another one of my DVDs, which completely fills out the picture at 720x480 [SAR 32:27 DAR 16:9]. What specifically causes the black bars to appear and at what ratio would I need to upscale the movie without cropping out parts of the frames and is it possible at all? I read somewhere I should upscale based on multiples of the source file pixels.

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