>From what I understand, you need to compare big images to big images for the minutiae algo to work good. If the verification images are small, they simply won't have enough minutiae.
I think Hans had a good point when he mentioned that the existing stitching code could be used. libfprint has the advantage that it doesn't guarantee interoperability between different scanners - that you can enroll with one scanner and verify with another. It doesn't need to have a very generic algorithm like the ones that academic papers focus on. The same device (and we're not even talking about the same model - it's the same physical device) produces very similar images all the time. There is already a method to score an overlap of 2 images that's used for stitching. If the rotation is taken care of, the rest should be possible. I was at some point thinking whether minutiae can be used as sort of "anchor points" to find approximate coordinates and angle (e.g. we have 3 similar minutiae which is not enough to compare but we can match their coordinates on 2 scans and use them to check for overlap). This would still benefit greatly from an improved enrollment procedure, though. I imagine the one where you tap the sensor instead of swiping, as swiping stretches the skin and distorts the image. Such enrollment would also need to compare frames along x, y and account for rotation... On Tue, Jan 30, 2018 at 2:40 AM Vasily Khoruzhick <anars...@gmail.com> wrote: > I suggest improving enrollment procedure. It should stitch big image > from several small images and use it later for comparison (using > whatever algorithm - minutiae algo also may work). > > On Mon, Jan 29, 2018 at 7:38 AM, Hans de Goede <hdego...@redhat.com> > wrote: > > Hi, > > > > On 23-01-18 22:58, Igor Filatov wrote: > >> > >> I've updated the driver to support the devices known so far. Please see > if > >> it works for you. Please send me your logs if not. I've enabled all > commands > >> for all devices (except 0x4031 which I've enabled only on my 0x0907 -- > no > >> idea what it does, but the response is 0x01). > >> > >> There's a bit mask in each command which you can use to enable/disable > >> commands for a particular device. > >> > >> As for calibration, the driver doesn't expect 0x03 because not all > devices > >> seem to return 0x03 or 0x01. Instead it will retry *only* if the > response is > >> 0x03 and until it's different. > >> > >> I've enabled reset & fuse load for my device. Although I haven't seen it > >> done by the original driver, it doesn't seem to hurt. So please see if > it > >> cause problems for you. Let's disable it only for devices where it does. > >> > >> https://github.com/iafilatov/libfprint > > > > > > This works for me with both the 0c16 and 0c26 readers I've access too. > > > > But we really need someone (any takers?) to implement a different type > > of recognition algorithm for these, not using minutia and then not treat > > them as swipe readers. Basically what we need is some form of image > > correlation > > algorithm. Perhaps the stitching code (which does not seem to do a very > good > > job IMHO) can be used, to see if 2 images can be made to mostly overlap > > with an acceptable shift. > > > > Note that when I last looking into this I did a quick duckduckgo search > > on low resolution fingerprint recognition and there are a number of > > academic papers on how this can be done using image correlation, so > > ideally some-one would go and implement something like this. > > > > Regards, > > > > Hans > > > >> On Fri, Jan 19, 2018 at 3:33 PM TeEmZe <t...@teemze.de > >> <mailto:t...@teemze.de>> wrote: > >> > >> Hi, > >> > >> Sadly I won't be able to get the data until next week, as I > currently > >> don't have access to the Laptop. I'll notify you as soon as I manage to > get > >> the data. > >> > >> Regards, > >> > >> Timo > >> > >> -----Original Message----- > >> From: Hans de Goede [mailto:hdego...@redhat.com > >> <mailto:hdego...@redhat.com>] > >> Sent: Thursday, 18 January 2018 16:14 > >> To: Sebastien Bechet <sebastien.bec...@osinix.com > >> <mailto:sebastien.bec...@osinix.com>>; Igor Filatov < > ia.fila...@gmail.com > >> <mailto:ia.fila...@gmail.com>> > >> Cc: TeEmZe <t...@teemze.de <mailto:t...@teemze.de>>; > >> konachan....@gmail.com <mailto:konachan....@gmail.com>; > >> fprint@lists.freedesktop.org <mailto:fprint@lists.freedesktop.org> > >> Subject: Re: [fprint] elan patch + poc 0x903 and 0x0C03 > >> > >> Hi, > >> > >> On 18-01-18 16:03, Sebastien Bechet wrote: > >> > Thank you Igor. Hans, you can try again with last version. > >> > >> Not tested, but looking at the code, it will loop in the > calibration, > >> my 2 devices both need a: > >> > >> if (result == 0x03) break; > >> > >> Directly after the: > >> > >> printf("Calibration Status: 0x%x\n", result); > >> > >> Line, currently the code only checks for result == 0x03 for the > result > >> of the get_cmd_status command, while it should check (for my devices) > the > >> result of the get_cmd_calibration command. > >> > >> Regards, > >> > >> Hans > >> > >> > >> > >> > > >> > I also tried to remove reset+fuseload then calibration not > working > >> > anymore for 0x0903. It seems it is a part for calibration (same > pdf > >> > file for reset _and_ calibration or .... reset _then_ > >> calibration?). > >> > > >> > https://github.com/sbechet/elanfp > >> > > >> > Konata and timo, can you give us width, height, firmware version > >> and > >> > calibration status using elanfp.c please? > >> > >> > >> > > >> > > >> > > >> > Le jeudi 18 janvier 2018 à 14:02 +0000, Igor Filatov a écrit : > >> >>> square and seems to contain the image 3 times > >> >> Could be because convert is hardcoded at 96x96. > >> >> > >> >> On Thu, 18 Jan 2018, 12:04 Hans de Goede, <hdego...@redhat.com > >> <mailto:hdego...@redhat.com>> > >> > >> >> wrote: > >> >>> Hi, > >> >>> > >> >>> On 18-01-18 10:48, Sébastien Béchet wrote: > >> >>>> On 17-01-18 19:21, Igor Filatov wrote: > >> >>>>> We didn't have the spec before so I had no idea how different > >> >>> devices worked. Especially given that some commands which > worked > >> >>> fine for me produced errors one other devices. Now that we have > >> the > >> >>> docs I'll work on adapting the driver. Naturally, any info you > >> have > >> >>> is welcome and so is any help with testing. > >> >>>> > >> >>>> I have done the > >> [synthesis](https://github.com/sbechet/elanfp/blo > >> >>> b/master/README.md) about all informations we have a prepare > >> >>> questions for KT. > >> >>> > >> >>> My 0x0c16 id reader has firmware version 1.56, resolution 96x96 > >> >>> > >> >>> I also have bought a stand-alone USB reader for when I would > find > >> >>> time to work on this, this has an usb-id of: 0x0c26. > >> >>> > >> >>> After aking these changes: > >> >>> > >> >>> --- elanfp.c~ 2018-01-18 10:58:59.919912347 +0100 > >> >>> +++ elanfp.c 2018-01-18 11:01:50.346280668 +0100 > >> >>> @@ -71,7 +71,8 @@ > >> >>> (desc.idVendor == 0x04f3) && (desc.idProduct > >> == > >> >>> 0x0903) || > >> >>> (desc.idVendor == 0x04f3) && (desc.idProduct > >> == > >> >>> 0x0907) || > >> >>> (desc.idVendor == 0x04f3) && (desc.idProduct > >> == > >> >>> 0x0c03) || > >> >>> - (desc.idVendor == 0x04f3) && (desc.idProduct > == > >> >>> 0x0c16) ) { > >> >>> + (desc.idVendor == 0x04f3) && (desc.idProduct > == > >> >>> 0x0c16) || > >> >>> + (desc.idVendor == 0x04f3) && (desc.idProduct > == > >> >>> 0x0c26) ) { > >> >>> r0 = 0; > >> >>> printf("Device with vid %x pid %x found.\n", > >> >>> desc.idVendor, desc.idProduct); > >> >>> break; > >> >>> @@ -156,7 +157,7 @@ > >> >>> printf("CMD Get Image Size sent\n"); > >> >>> } > >> >>> r0 = libusb_bulk_transfer(handle, BULK_EP3_IN, img_buf, > 4, > >> >>> &transferred, 0); > >> >>> - printf("Width x height = %dx%d\n", img_buf[0], > img_buf[2]); > >> >>> + printf("Width x height = %dx%d\n", (unsigned > >> char)img_buf[0], > >> >>> (unsigned char)img_buf[2]); > >> >>> > >> >>> /* calibration */ > >> >>> > >> >>> @@ -180,6 +181,7 @@ > >> >>> } > >> >>> r0 = libusb_bulk_transfer(handle, BULK_EP3_IN, > >> &result, > >> >>> 1, &transferred, 0); > >> >>> printf("Calibration Status: 0x%x\n", result); > >> >>> + if (result == 0x03) break; > >> >>> > >> >>> r0 = libusb_bulk_transfer(handle, BULK_EP1_OUT, > >> >>> get_cmd_status, 2, &transferred, 0); > >> >>> if((r0 == 0) && (transferred == 2)) { > >> >>> > >> >>> This one works with the POC too, although for some reason the > >> >>> generated out.png is square and seems to contain the image 3 > >> times? > >> >>> > >> >>> This one has firmware version 1.64, resolution 64x144 and as > >> shown > >> >>> in the necessary changes this one does report a calibration > >> status > >> >>> of 0x03 when it is done with the calibration, I think we should > >> add > >> >>> an extra column for this to the hardware report table. > >> >>> > >> >>> Regards, > >> >>> > >> >>> Hans > >> > > _______________________________________________ > > fprint mailing list > > fprint@lists.freedesktop.org > > https://lists.freedesktop.org/mailman/listinfo/fprint >
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