On 1/22/07, abel deuring <adeur...@gmx.net> wrote: > m. allan noah wrote: > > >> > But back to the problem I have/had with Etienne's suggstion for the > >> > "relations" between page size and scan window coordinates: It does > >> > not make much sense to allow to set a scan window in overscan mode: > >> > The backend should calculate the scan window settings automatically > >> > from the page size, and disable the options tl-x, tl-y, br-x, br-y. > >> > >> No ! If a user want to scan only a portion of the paper, he must be able > >> to set scan area, but as long as there is no scan surface, we use paper > >> size as scan surface. That make sense ! > > > > you missed the point here. we are talking about an overscan option, which > > causes the scanner to add space all around the scan, such that the back- > > ground shows thru. > > > > but i think a person might want to overscan and still have only a > > small area of the page (one of the corners?) i think i can work this > > out, and still be compatible with the text of our suggestion. > > Since the "level" of page size and skew detection is quite low in > the scanners we're talking about, I think a backend does not need to > do much here: In overscan mode, the backend simply returns the image > of the document surrounded by "easily distinguishable", typically > "dark" pixels; it is up to the frontend to detect the page borders > and rotation angle. > > All this does not mean that the frontend cannot let the user select > a smaller scan window within the page area -- but the clipping of > the image must be done by the frontend. >
i agree completely other than the last sentence. it should be possible for the backend to let the user select overscan mode, and then adjust the scan area/papersize as needed to set tl-x/y 0,0 to the black area 16mm outside of the paper. i dont think this violates the spirit of the standard proposal, and it keeps overscan mode as similar to the other modes as possible. in fact, i think this is the right thing to do in sane1, given recent user complaints on this mailing list. allan -- "The truth is an offense, but not a sin"
