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aes: unify image processing code for AuthenTec devices

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Move overlap detection and assembling code into aeslib to prevent
code duplication

https://bugs.freedesktop.org/show_bug.cgi?id=57426
This commit is contained in:
Vasily Khoruzhick
2012-11-17 15:32:25 +03:00
committed by Bastien Nocera
parent 5b20892dd4
commit 8c5f2e6434
5 changed files with 144 additions and 356 deletions
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138
libfprint/drivers/aes1610.c
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@@ -4,6 +4,7 @@
* Copyright (C) 2007 Cyrille Bagard
* Copyright (C) 2007 Vasily Khoruzhick
* Copyright (C) 2009 Guido Grazioli <guido.grazioli@gmail.com>
* Copyright (C) 2012 Vasily Khoruzhick <anarsoul@gmail.com>
*
* Based on code from libfprint aes2501 driver.
*
@@ -147,131 +148,6 @@ static void generic_read_ignore_data(struct fpi_ssm *ssm, size_t bytes)
}
}
/****** IMAGE PROCESSING ******/
/* find overlapping parts of frames */
static unsigned int find_overlap(unsigned char *first_frame,
unsigned char *second_frame, unsigned int *min_error)
{
unsigned int dy;
unsigned int not_overlapped_height = 0;
*min_error = 255 * FRAME_SIZE;
for (dy = 0; dy < FRAME_HEIGHT; dy++) {
/* Calculating difference (error) between parts of frames */
unsigned int i;
unsigned int error = 0;
for (i = 0; i < FRAME_WIDTH * (FRAME_HEIGHT - dy); i++) {
/* Using ? operator to avoid abs function */
error += first_frame[i] > second_frame[i] ?
(first_frame[i] - second_frame[i]) :
(second_frame[i] - first_frame[i]);
}
/* Normalize error */
error *= 15;
error /= i;
if (error < *min_error) {
*min_error = error;
not_overlapped_height = dy;
}
first_frame += FRAME_WIDTH;
}
return not_overlapped_height;
}
/* assemble a series of frames into a single image */
static unsigned int assemble(struct aes1610_dev *aesdev, unsigned char *output,
gboolean reverse, unsigned int *errors_sum)
{
uint8_t *assembled = output;
int frame;
uint32_t image_height = FRAME_HEIGHT;
unsigned int min_error;
size_t num_strips = aesdev->strips_len;
GSList *list_entry = aesdev->strips;
*errors_sum = 0;
if (num_strips < 1)
return 0;
/* Rotating given data by 90 degrees
* Taken from document describing aes1610 image format
* TODO: move reversing detection here */
if (reverse)
output += (num_strips - 1) * FRAME_SIZE;
for (frame = 0; frame < num_strips; frame++) {
aes_assemble_image(list_entry->data, FRAME_WIDTH, FRAME_HEIGHT, output);
if (reverse)
output -= FRAME_SIZE;
else
output += FRAME_SIZE;
list_entry = g_slist_next(list_entry);
}
/* Detecting where frames overlaped */
output = assembled;
for (frame = 1; frame < num_strips; frame++) {
int not_overlapped;
output += FRAME_SIZE;
not_overlapped = find_overlap(assembled, output, &min_error);
*errors_sum += min_error;
image_height += not_overlapped;
assembled += FRAME_WIDTH * not_overlapped;
memcpy(assembled, output, FRAME_SIZE);
}
return image_height;
}
static void assemble_and_submit_image(struct fp_img_dev *dev)
{
struct aes1610_dev *aesdev = dev->priv;
size_t final_size;
struct fp_img *img;
unsigned int errors_sum, r_errors_sum;
fp_dbg("");
BUG_ON(aesdev->strips_len == 0);
/* reverse list */
aesdev->strips = g_slist_reverse(aesdev->strips);
/* create buffer big enough for max image */
img = fpi_img_new(aesdev->strips_len * FRAME_SIZE);
img->flags = FP_IMG_COLORS_INVERTED;
img->height = assemble(aesdev, img->data, FALSE, &errors_sum);
img->height = assemble(aesdev, img->data, TRUE, &r_errors_sum);
if (r_errors_sum > errors_sum) {
img->height = assemble(aesdev, img->data, FALSE, &errors_sum);
img->flags |= FP_IMG_V_FLIPPED | FP_IMG_H_FLIPPED;
fp_dbg("normal scan direction");
} else {
fp_dbg("reversed scan direction");
}
/* now that overlap has been removed, resize output image buffer */
final_size = img->height * FRAME_WIDTH;
img = fpi_img_resize(img, final_size);
/* FIXME: ugly workaround */
if (img->height < 12)
img->height = 12;
fpi_imgdev_image_captured(dev, img);
/* free strips and strip list */
g_slist_foreach(aesdev->strips, (GFunc) g_free, NULL);
g_slist_free(aesdev->strips);
aesdev->strips = NULL;
aesdev->strips_len = 0;
aesdev->blanks_count = 0;
}
/****** FINGER PRESENCE DETECTION ******/
@@ -732,11 +608,19 @@ static void capture_read_strip_cb(struct libusb_transfer *transfer)
/* stop capturing if MAX_FRAMES is reached */
if (aesdev->blanks_count > 10 || g_slist_length(aesdev->strips) >= MAX_FRAMES) {
struct fp_img *img;
fp_dbg("sending stop capture.... blanks=%d frames=%d", aesdev->blanks_count, g_slist_length(aesdev->strips));
/* send stop capture bits */
aes_write_regv(dev, capture_stop, G_N_ELEMENTS(capture_stop), stub_capture_stop_cb, NULL);
/* assemble image and submit it to library */
assemble_and_submit_image(dev);
aesdev->strips = g_slist_reverse(aesdev->strips);
img = aes_assemble(aesdev->strips, aesdev->strips_len,
FRAME_WIDTH, FRAME_HEIGHT);
g_slist_free_full(aesdev->strips, (GFunc) g_free);
aesdev->strips = NULL;
aesdev->strips_len = 0;
aesdev->blanks_count = 0;
fpi_imgdev_image_captured(dev, img);
fpi_imgdev_report_finger_status(dev, FALSE);
/* marking machine complete will re-trigger finger detection loop */
fpi_ssm_mark_completed(ssm);