I took the file you provided and opened it with KPDF, the PDF viewer of KDE3 on a Linux system. I used the snapshot tool by marking the area to be copied with the mouse cursor and saved this extract directly to a PNG file. The same procedure can be done on a Windows system with the Adobe Reader and IrfanView, which is able to save the contents of the clipboard directly as PDF. But the loss in quality remains.gcheer3 wrote:[…] Thorsten, how did you extract the picture from the PDF file? Do you use some sofeware? I think this is the easier way. I am using windows, pdfcrop may not work very well as you said. […]
Stefan already provided a solution. Another approach could be to include the untouched file (Doc4.pdf) with the \inlcudegraphics command and use its trim or viewport option. This only works when compiling directly with pdflatex. Please refer to the documentation (Section 4 - Including graphics files, p. 9ff) of the graphicx package first. In case of occurring questions, feel free to ask.