Small pyqt application to crop the margins and compress the pdf.

1. Use Tool -> Crop

1. Use Tool -> Compress

1. pyqt5
2. pymupdf
3. ghostscript==9.25 (version 10.0 not working)

• All pages in the pdf will be cropped according to the area you selected.
• Instead of setting visible area of the pdf, the texts beyond visible area are removed by ghost script.
• Destructive crop pdf by ghost script: https://stackoverflow.com/questions/457207/cropping-pages-of-a-pdf-file#comment95568261_465901
• Compress by ghost script: https://gist.github.com/ahmed-musallam/27de7d7c5ac68ecbd1ed65b6b48416f9