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aes1610: imaging improvements

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bz threshold is now 10 (instead of 15). I think it is ok for the moment.
If we manage to get higher image quality in the future, we'll change that.

max_frame is set to 350. 150 was too low => incomplete fingerprints

the driver was designed to stop the acquisition as soon as it gets a blank
frame (=> incomplete fingerprints). Now it waits to have at least 50 blank
frames before stopping.
This commit is contained in:
Anthony Bretaudeau 2007-11-26 17:51:31 +00:00 committed by Daniel Drake
parent 4e2be56db7
commit 8e0e8e4386
1 changed files with 14 additions and 23 deletions
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37
libfprint/drivers/aes1610.c
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@ -58,7 +58,7 @@
#define FRAME_SIZE (FRAME_WIDTH * FRAME_HEIGHT)
/* maximum number of frames to read during a scan */
/* FIXME reduce substantially */
#define MAX_FRAMES 150
#define MAX_FRAMES 350
struct aes1610_regwrite {
unsigned char reg;
@ -245,24 +245,6 @@ static int await_finger_on(struct fp_img_dev *dev)
return (r < 0) ? r : 0;
}
/* Read the value of a specific register from a register dump */
static int regval_from_dump(unsigned char *data, uint8_t target)
{
if (*data != FIRST_AES1610_REG) {
fp_err("not a register dump");
return -EILSEQ;
}
if (!(FIRST_AES1610_REG <= target || target >= LAST_AES1610_REG)) {
fp_err("out of range");
return -EINVAL;
}
target -= FIRST_AES1610_REG;
target *= 2;
return data[target + 1];
}
/* find overlapping parts of frames */
static unsigned int find_overlap(unsigned char *first_frame,
unsigned char *second_frame, unsigned int *min_error)
@ -494,6 +476,7 @@ static int capture(struct fp_img_dev *dev, gboolean unconditional,
unsigned char *imgptr;
unsigned char buf[665];
int sum;
unsigned int count_blank = 0;
int i;
/* FIXME can do better here in terms of buffer management? */
@ -521,9 +504,9 @@ static int capture(struct fp_img_dev *dev, gboolean unconditional,
memcpy(imgptr, buf + 1, 128*4);
imgptr += 128*4;
for (nstrips = 0; nstrips < MAX_FRAMES; nstrips++) {
int threshold;
/* we start at 2 because we captured 2 frames above. the above captures
* should possibly be moved into the loop below, or discarded altogether */
for (nstrips = 2; nstrips < MAX_FRAMES - 2; nstrips++) {
r = write_regv(dev, strip_scan_reqs, G_N_ELEMENTS(strip_scan_reqs));
if (r < 0)
goto err;
@ -552,6 +535,12 @@ static int capture(struct fp_img_dev *dev, gboolean unconditional,
}
fp_dbg("sum=%d", sum);
if (sum == 0)
count_blank++;
else
count_blank = 0;
/* if we got 50 blank frames, assume scan has ended. */
if (count_blank >= 50)
break;
}
@ -563,12 +552,14 @@ static int capture(struct fp_img_dev *dev, gboolean unconditional,
goto err;
memcpy(imgptr, buf + 1, 128*4);
imgptr += 128*4;
nstrips++;
r = read_data(dev, buf, 665);
if (r < 0)
goto err;
memcpy(imgptr, buf + 1, 128*4);
imgptr += 128*4;
nstrips++;
if (nstrips == MAX_FRAMES)
fp_warn("swiping finger too slow?");
@ -616,7 +607,7 @@ struct fp_img_driver aes1610_driver = {
* binarized scan quality is good, minutiae detection is accurate,
* it's just that we get fewer minutiae than other scanners (less scanning
* area) */
.bz3_threshold = 15,
.bz3_threshold = 10,
.init = dev_init,
.exit = dev_exit,