convert \ -verbose \ -density 150 \ -trim \ test.pdf \ -quality 100 \ -flatten \ -sharpen 0x1.0 \ 24-18.jpg

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gs -dPDFA -dBATCH -dNOPAUSE -sProcessColorModel=DeviceRGB -sDEVICE=pdfwrite -sPDFACompatibilityPolicy=1 -sOutputFile=output_filename.pdf input_filename.pdf

via Olivier DOSSMANN et OpenNews