Did i get you right, there is no way to use my device with libfprint matching alorythm, unless I try to use my scanner as a swipe-type one? That's exactly what you did with your Elan driver, right? The scan area is indeed very small. And i am curious why does it return several images instead of one? Isn't it simplier to process in any case, especially when it is press-type sensor? Just saying.
2018-02-12 4:57 GMT+07:00 Igor Filatov <ia.fila...@gmail.com>: > Hi, > > 1. You need to find out the correct format of returned data. By correct I > mean the one that allows to decode an image of a fingerprint. This is > necessary for the matching algorithm to work. The .pgm files in your repo > don't look like fingerprints, right? They look like noise because the > dimensions are incorrect. > 2. Raw data is not fine. I've tried a few variant and it looks like your > device returns 8bit 114x57 images. And it returns 5 of them together. Not > sure, maybe the driver is supposed to combine them in some way. > 3. libfrpint doesn't care that much about pixel dimensions. What is does > very much care about is the physical size of the fingerptint that a device > can scan. In your case it's very small. It won't work. Welcome to the > club... See the recent discussions in the mailing list about the Elan > driver I'm writing. It has the same problem tldr: libfprint uses a fp > matching algo that detects minutiae (notable elements of a fingerprint) and > needs to see 60+% of a print surface (from my observations, ymmv) to work > reliably. Your reader covers maybe 15%. That's not enough. Original drivers > for such devices for Windows, phones etc. probably have a different > matching algo. > > On Sun, Feb 11, 2018 at 1:25 PM Indev <inde...@gmail.com> wrote: > >> Hello, >> >> I am writing a driver for Egis Technology Inc. sensor (ID 1c7a:0570), but >> having few problems. >> First of all, i have no idea what is the model of my sensor. I've checked >> USB.org product lists as well as manufacturer's website and Acer website (I >> am using Acer Swift 1 SF-113-31 with this sensor integrated). >> I failed to find any kind of information about my device and started to >> write driver without that. >> I was managed to recreate driver exchange process and get data from the >> sensor. >> This is the press-type sensor and it returns 32512 bytes of data in one >> packet, which seem to be raw image data. >> I don't know what is the size of the returned image, so i've picked up >> the most suitable one for libfprint driver. >> Couple days ago i finished libfprint driver and it works fine, except of >> the fact that the verify_live example from libfprint is not able to do >> correct verification. It can't recognize same finger again and allows to >> pass verification by another finger, which is kinda funny. >> >> I have absolutely no experience with fingerprint scanner and I was hoping >> that someone here could help me. >> This is the repository of my driver: https://github.com/indev29/egis0570 >> The 'scans' directory contains examples of fingerprint scans converted >> into different sized .pgm images as well as raw binary data, received from >> sensor. >> Directories names ("scans/finger_avg_NUM") indicate average color value, >> which is more, when i press harder on sensor. >> >> My questions are: >> 1. Should i use this raw image data in my libfprint driver or should i >> process it somehow first? >> 2. If raw data is fine, why am i not able to do verification correctly? >> 3. Does libfprint care about image size? Can the wrong image size be the >> thing in my case (i am using 254x128) >> >> Thanks in advance, >> Indev >> _______________________________________________ >> fprint mailing list >> fprint@lists.freedesktop.org >> https://lists.freedesktop.org/mailman/listinfo/fprint >> >
_______________________________________________ fprint mailing list fprint@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/fprint
