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lib: move line assembling routines out of vfs5011 into common code

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This commit is contained in:
Vasily Khoruzhick
2015-09-05 09:38:10 -07:00
parent 6fc5293e83
commit b51fa446e3
3 changed files with 183 additions and 138 deletions
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132
libfprint/assembling.c
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@@ -1,6 +1,7 @@
/*
* Image assembling routines
* Copyright (C) 2007-2008 Daniel Drake <dsd@gentoo.org>
* Copyright (C) 2013 Arseniy Lartsev <arseniy@chalmers.se>
* Copyright (C) 2015 Vasily Khoruzhick <anarsoul@gmail.com>
*
* This library is free software; you can redistribute it and/or
@@ -275,3 +276,134 @@ struct fp_img *fpi_assemble_frames(struct fpi_frame_asmbl_ctx *ctx,
return img;
}
static int cmpint(const void *p1, const void *p2, gpointer data)
{
int a = *((int *)p1);
int b = *((int *)p2);
if (a < b)
return -1;
else if (a == b)
return 0;
else
return 1;
}
static void median_filter(int *data, int size, int filtersize)
{
int i;
int *result = (int *)g_malloc0(size*sizeof(int));
int *sortbuf = (int *)g_malloc0(filtersize*sizeof(int));
for (i = 0; i < size; i++) {
int i1 = i - (filtersize-1)/2;
int i2 = i + (filtersize-1)/2;
if (i1 < 0)
i1 = 0;
if (i2 >= size)
i2 = size-1;
g_memmove(sortbuf, data+i1, (i2-i1+1)*sizeof(int));
g_qsort_with_data(sortbuf, i2-i1+1, sizeof(int), cmpint, NULL);
result[i] = sortbuf[(i2-i1+1)/2];
}
memmove(data, result, size*sizeof(int));
g_free(result);
g_free(sortbuf);
}
static void interpolate_lines(struct fpi_line_asmbl_ctx *ctx,
GSList *line1, float y1, GSList *line2,
float y2, unsigned char *output, float yi, int size)
{
int i;
unsigned char p1, p2;
if (!line1 || !line2)
return;
for (i = 0; i < size; i++) {
p1 = ctx->get_pixel(ctx, line1, i);
p2 = ctx->get_pixel(ctx, line2, i);
output[i] = (float)p1
+ (yi - y1)/(y2 - y1)*(p2 - p1);
}
}
static int min(int a, int b) {return (a < b) ? a : b; }
/* Rescale image to account for variable swiping speed */
struct fp_img *fpi_assemble_lines(struct fpi_line_asmbl_ctx *ctx,
GSList *lines, size_t lines_len)
{
/* Number of output lines per distance between two scanners */
int i;
GSList *row1, *row2;
float y = 0.0;
int line_ind = 0;
int *offsets = (int *)g_malloc0((lines_len / 2) * sizeof(int));
unsigned char *output = g_malloc0(ctx->line_width * ctx->max_height);
struct fp_img *img;
fp_dbg("%llu", g_get_real_time());
row1 = lines;
for (i = 0; (i < lines_len - 1) && row1; i += 2) {
int bestmatch = i;
int bestdiff = 0;
int j, firstrow, lastrow;
firstrow = i + 1;
lastrow = min(i + ctx->max_search_offset, lines_len - 1);
row2 = g_slist_next(row1);
for (j = firstrow; j <= lastrow; j++) {
int diff = ctx->get_deviation(ctx,
row1,
row2);
if ((j == firstrow) || (diff < bestdiff)) {
bestdiff = diff;
bestmatch = j;
}
row2 = g_slist_next(row2);
}
offsets[i / 2] = bestmatch - i;
fp_dbg("%d", offsets[i / 2]);
row1 = g_slist_next(row1);
if (row1)
row1 = g_slist_next(row1);
}
median_filter(offsets, (lines_len / 2) - 1, ctx->median_filter_size);
fp_dbg("offsets_filtered: %llu", g_get_real_time());
for (i = 0; i <= (lines_len / 2) - 1; i++)
fp_dbg("%d", offsets[i]);
row1 = lines;
for (i = 0; i < lines_len - 1; i++, row1 = g_slist_next(row1)) {
int offset = offsets[i/2];
if (offset > 0) {
float ynext = y + (float)ctx->resolution / offset;
while (line_ind < ynext) {
if (line_ind > ctx->max_height - 1)
goto out;
interpolate_lines(ctx,
row1, y,
g_slist_next(row1),
ynext,
output + line_ind * ctx->line_width,
line_ind,
ctx->line_width);
line_ind++;
}
y = ynext;
}
}
out:
img = fpi_img_new(ctx->line_width * line_ind);
img->height = line_ind;
img->width = ctx->line_width;
img->flags = FP_IMG_V_FLIPPED;
g_memmove(img->data, output, ctx->line_width * line_ind);
g_free(offsets);
g_free(output);
return img;
}