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Image standardization

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Initially supports flipping and colour inversion
This commit is contained in:
Daniel Drake 2007-10-27 12:07:11 +01:00
parent 0ddfef6c21
commit 9960a7ff34
5 changed files with 75 additions and 0 deletions
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7
examples/img_capture.c
View file

@ -92,6 +92,13 @@ int main(void)
goto out_close;
}
fp_img_standardize(img);
r = fp_img_save_to_file(img, "finger_standardized.pgm");
if (r) {
fprintf(stderr, "standardized img save failed, code %d\n", r);
goto out_close;
}
r = 0;
out_close:
fp_dev_close(dev);

1
libfprint/drivers/uru4000.c
View file

@ -294,6 +294,7 @@ static int capture(struct fp_img_dev *dev, gboolean unconditional,
img = fpi_img_resize(img, image_size);
img->width = IMG_WIDTH;
img->height = IMG_HEIGHT;
img->flags = FP_IMG_V_FLIPPED | FP_IMG_H_FLIPPED | FP_IMG_COLORS_INVERTED;
*ret = img;
return 0;

6
libfprint/fp_internal.h
View file

@ -155,10 +155,16 @@ struct fp_print_data {
struct fp_print_data *fpi_print_data_new(struct fp_dev *dev, size_t length);
int fpi_print_data_compatible(struct fp_dev *dev, struct fp_print_data *data);
/* bit values for fp_img.flags */
#define FP_IMG_V_FLIPPED (1<<0)
#define FP_IMG_H_FLIPPED (1<<1)
#define FP_IMG_COLORS_INVERTED (1<<2)
struct fp_img {
int width;
int height;
size_t length;
uint16_t flags;
unsigned char data[0];
};

1
libfprint/fprint.h
View file

@ -97,6 +97,7 @@ int fp_img_get_height(struct fp_img *img);
int fp_img_get_width(struct fp_img *img);
unsigned char *fp_img_get_data(struct fp_img *img);
int fp_img_save_to_file(struct fp_img *img, char *path);
void fp_img_standardize(struct fp_img *img);
/* Library */
int fp_init(void);

60
libfprint/img.c
View file

@ -104,3 +104,63 @@ API_EXPORTED int fp_img_save_to_file(struct fp_img *img, char *path)
return 0;
}
static void vflip(struct fp_img *img)
{
int width = img->width;
int data_len = img->width * img->height;
unsigned char rowbuf[width];
int i;
for (i = 0; i < img->height / 2; i++) {
int offset = i * width;
int swap_offset = data_len - (width * (i + 1));
/* copy top row into buffer */
memcpy(rowbuf, img->data + offset, width);
/* copy lower row over upper row */
memcpy(img->data + offset, img->data + swap_offset, width);
/* copy buffer over lower row */
memcpy(img->data + swap_offset, rowbuf, width);
}
}
static void hflip(struct fp_img *img)
{
int width = img->width;
unsigned char rowbuf[width];
int i, j;
for (i = 0; i < img->height; i++) {
int offset = i * width;
memcpy(rowbuf, img->data + offset, width);
for (j = 0; j < width; j++)
img->data[offset + j] = rowbuf[width - j - 1];
}
}
static void invert_colors(struct fp_img *img)
{
int data_len = img->width * img->height;
int i;
for (i = 0; i < data_len; i++)
img->data[i] = 0xff - img->data[i];
}
API_EXPORTED void fp_img_standardize(struct fp_img *img)
{
if (img->flags & FP_IMG_V_FLIPPED) {
vflip(img);
img->flags &= ~FP_IMG_V_FLIPPED;
}
if (img->flags & FP_IMG_H_FLIPPED) {
hflip(img);
img->flags &= ~FP_IMG_H_FLIPPED;
}
if (img->flags & FP_IMG_COLORS_INVERTED) {
invert_colors(img);
img->flags &= ~FP_IMG_COLORS_INVERTED;
}
}