Convert cropped PDF to ePub

Hi,

i have some PDF with a text layer. With "PDFCropMargins" i can crop the page number together with the blank area around the text. That part of every page is not realy cropped, its still not visible in the PDF viewer. When Calibre is converter the cropped PDF it doesn't ignore the page numbers. How can i do that? Can Calibre only use the "cropped" pages as input exclude the cropped parts?

PDFCropMargins keeps the text layer and after convertion there are no problems with wrong OCR.