mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-11-30 13:41:48 +00:00
253 lines
7.3 KiB
C
253 lines
7.3 KiB
C
/******************************************************************
|
|
|
|
Copyright (C) 1996 by Brian Scearce
|
|
|
|
Permission is hereby granted, free of charge, to any person obtaining a
|
|
copy of this software and associated documentation files (the
|
|
"Software"), to deal in the Software without restriction, including
|
|
without limitation the rights to use, copy, modify, merge, publish,
|
|
and/or distribute copies of the Software, and to permit persons to whom
|
|
the Software is furnished to do so, subject to the following conditions:
|
|
|
|
1. The above copyright notice and this permission notice shall be
|
|
included in all copies or substantial portions of the Software.
|
|
|
|
2. Redistribution for profit requires the express, written permission of
|
|
the author.
|
|
|
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
|
|
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
|
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
|
|
IN NO EVENT SHALL BRIAN SCEARCE BE LIABLE FOR ANY CLAIM, DAMAGES OR
|
|
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
|
|
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
|
|
OTHER DEALINGS IN THE SOFTWARE.
|
|
******************************************************************/
|
|
|
|
/** Fixdark
|
|
Routine to repair dark current artifacts in qcam output.
|
|
Basic idea: the Qcam CCD suffers from "dark current";
|
|
that is, some of the CCD pixels will leak current under
|
|
long exposures, even if they're in the dark, and this
|
|
shows up as ugly speckling on images taken in low light.
|
|
|
|
Fortunately, the leaky pixels are the same from shot to
|
|
shot. So, we can figure out which pixels are leaky by
|
|
taking some establishing shots in the dark, and try to
|
|
fix those pixels on subsequent shots. The dark
|
|
establishing shots need only be done once per camera.
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <assert.h>
|
|
#include "qcam.h"
|
|
#define MAX_LOOPS 10
|
|
#define FNAME "qcam.darkfile"
|
|
|
|
static unsigned char master_darkmask1[MAX_HEIGHT][MAX_WIDTH];
|
|
static unsigned char master_darkmask2[MAX_HEIGHT/2+1][MAX_WIDTH/2+1];
|
|
static unsigned char master_darkmask4[MAX_HEIGHT/4+1][MAX_WIDTH/4+1];
|
|
|
|
/*
|
|
int
|
|
read_darkmask()
|
|
{
|
|
int x, y;
|
|
int min_bright;
|
|
char darkfile[BUFSIZ], *p;
|
|
FILE *fp;
|
|
|
|
strcpy(darkfile, CONFIG_FILE);
|
|
if ( (p = strrchr(darkfile, '/'))) {
|
|
strcpy(p+1, FNAME);
|
|
} else {
|
|
strcpy(darkfile, FNAME);
|
|
}
|
|
|
|
if (!(fp = fopen(darkfile, "r"))) {
|
|
#ifdef DEBUG
|
|
fprintf(stderr, "Can't open darkfile %s\n", darkfile);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
if (fread(master_darkmask1, sizeof(unsigned char), MAX_WIDTH*MAX_HEIGHT, fp) !=
|
|
MAX_WIDTH*MAX_HEIGHT) {
|
|
#ifdef DEBUG
|
|
fprintf(stderr, "Error reading darkfile\n");
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
for (y = 0; y < MAX_HEIGHT; y += 2) {
|
|
for (x = 0; x < MAX_WIDTH; x += 2) {
|
|
min_bright = master_darkmask1[y][x];
|
|
if (y < MAX_HEIGHT-1 && master_darkmask1[y+1][x] < min_bright)
|
|
min_bright = master_darkmask1[y+1][x];
|
|
if (x < MAX_WIDTH-1 && master_darkmask1[y][x+1] < min_bright)
|
|
min_bright = master_darkmask1[y][x+1];
|
|
if (y < MAX_HEIGHT-1 && x < MAX_WIDTH-1 && master_darkmask1[y+1][x+1] < min_bright)
|
|
min_bright = master_darkmask1[y+1][x+1];
|
|
master_darkmask2[y/2][x/2] = min_bright;
|
|
assert(y/2 < MAX_HEIGHT/2+1);
|
|
assert(x/2 < MAX_WIDTH/2+1);
|
|
}
|
|
}
|
|
|
|
for (y = 0; y < MAX_HEIGHT/2; y += 2) {
|
|
for (x = 0; x < MAX_WIDTH/2; x += 2) {
|
|
min_bright = master_darkmask2[y][x];
|
|
if (y < MAX_HEIGHT/2-1 && master_darkmask2[y+1][x] < min_bright)
|
|
min_bright = master_darkmask2[y+1][x];
|
|
if (x < MAX_WIDTH/2-1 && master_darkmask2[y][x+1] < min_bright)
|
|
min_bright = master_darkmask2[y][x+1];
|
|
if (y < MAX_HEIGHT/2-1 && x < MAX_WIDTH-1 && master_darkmask2[y+1][x+1] < min_bright)
|
|
min_bright = master_darkmask2[y+1][x+1];
|
|
master_darkmask4[y/2][x/2] = min_bright;
|
|
assert(y/2 < MAX_HEIGHT/4+1);
|
|
assert(x/2 < MAX_WIDTH/4+1);
|
|
}
|
|
}
|
|
|
|
fclose(fp);
|
|
return 1;
|
|
}
|
|
*/
|
|
|
|
|
|
/** fixdark
|
|
We first record a list of bad leaky pixels, by making a
|
|
number of exposures in the dark. master_darkmask holds
|
|
this information. It's a map of the CCD.
|
|
master_darkmask[y][x] == val means that the pixel is
|
|
unreliable for brightnesses of "val" and above.
|
|
|
|
We go over the image. If a pixel is bad, look at the
|
|
adjacent four pixels, average the ones that have good
|
|
values, and use that instead.
|
|
*/
|
|
|
|
int
|
|
fixdark(const struct qcam *q, scanbuf *scan)
|
|
{
|
|
static int init = 0;
|
|
static int smallest_dm = 255;
|
|
unsigned char darkmask[MAX_HEIGHT][MAX_WIDTH];
|
|
unsigned char new_image[MAX_HEIGHT][MAX_WIDTH];
|
|
int width, height;
|
|
int max_width, max_height;
|
|
int x, y;
|
|
int ccd_x, ccd_y;
|
|
int pixelcount, pixeltotal;
|
|
int again, loopcount = 0;
|
|
int val;
|
|
int brightness = q->brightness;
|
|
int scale = q->transfer_scale;
|
|
|
|
if (!init) {
|
|
if (!read_darkmask()) return 0;
|
|
for (y = 0; y < MAX_HEIGHT; y++)
|
|
for (x = 0; x < MAX_HEIGHT; x++)
|
|
if (master_darkmask1[y][x] < smallest_dm) {
|
|
smallest_dm = master_darkmask1[y][x];
|
|
#ifdef DEBUG
|
|
fprintf(stderr, "Smallest mask is %d at (%d, %d)\n",
|
|
smallest_dm, x, y);
|
|
#endif
|
|
}
|
|
init = 1;
|
|
}
|
|
|
|
if (brightness < smallest_dm) {
|
|
#ifdef DEBUG
|
|
fprintf(stderr, "Brightness %d (dark current starts at %d), no fixup needed\n",
|
|
brightness, smallest_dm);
|
|
#endif
|
|
return 1;
|
|
}
|
|
|
|
width = q->width / scale;
|
|
height = q->height / scale;
|
|
|
|
max_height = MAX_HEIGHT / scale;
|
|
max_width = MAX_WIDTH / scale;
|
|
for (y = 0; y < max_height; y++)
|
|
for (x = 0; x < max_width; x++)
|
|
if (scale == 1) {
|
|
darkmask[y][x] = master_darkmask1[y][x];
|
|
} else if (scale == 2) {
|
|
darkmask[y][x] = master_darkmask2[y][x];
|
|
} else if (scale == 4) {
|
|
darkmask[y][x] = master_darkmask4[y][x];
|
|
} else {
|
|
#ifdef DEBUG
|
|
fprintf(stderr, "Bad transfer_scale in darkmask assignment!\n");
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
do {
|
|
again = 0;
|
|
ccd_y = (q->top-1)/scale;
|
|
for (y = 0; y < height; y++, ccd_y++) {
|
|
ccd_x = q->left-1;
|
|
ccd_x /= 2;
|
|
ccd_x *= 2;
|
|
ccd_x /= scale;
|
|
for (x = 0; x < width; x++, ccd_x++) {
|
|
val = scan[y*width + x];
|
|
if (brightness < darkmask[ccd_y][ccd_x]) { /* good pixel */
|
|
new_image[y][x] = val;
|
|
} else { /* bad pixel */
|
|
/* look at nearby pixels, average the good values */
|
|
pixelcount = 0;
|
|
pixeltotal = 0;
|
|
if (x > 0) { /* left */
|
|
if (brightness < darkmask[ccd_y][ccd_x-1]) {
|
|
pixelcount++;
|
|
pixeltotal += scan[y*width + x - 1];
|
|
}
|
|
}
|
|
if (x < width-1) { /* right */
|
|
if (brightness < darkmask[ccd_y][ccd_x+1]) {
|
|
pixelcount++;
|
|
pixeltotal += scan[y*width + x + 1];
|
|
}
|
|
}
|
|
if (y > 0) { /* above */
|
|
if (brightness < darkmask[ccd_y-1][ccd_x]) {
|
|
pixelcount++;
|
|
pixeltotal += scan[(y-1)*width + x];
|
|
}
|
|
}
|
|
if (y < height-1) { /* below */
|
|
if (brightness < darkmask[ccd_y+1][ccd_x]) {
|
|
pixelcount++;
|
|
pixeltotal += scan[(y+1)*width + x];
|
|
}
|
|
}
|
|
|
|
if (pixelcount == 0) { /* no valid neighbors! */
|
|
again = 1;
|
|
} else {
|
|
new_image[y][x] = pixeltotal / pixelcount;
|
|
/* mark this pixel as valid, so we don't loop forever */
|
|
darkmask[ccd_y][ccd_x] = 255;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
for (y = 0; y < height; y++)
|
|
for (x = 0; x < width; x++)
|
|
scan[y*width + x] = new_image[y][x];
|
|
|
|
} while (loopcount++ < MAX_LOOPS && again);
|
|
#ifdef DEBUG
|
|
fprintf(stderr, "Darkmask fix took %d loop%s\n",
|
|
loopcount, (loopcount == 1)?"":"s");
|
|
#endif
|
|
return 1;
|
|
}
|
|
|