opencv里边的一段源码,有点看不懂,求指点!
opencv里面的一段源码,有点看不懂,求指点!!!
struct RGB2HSV_b
{
typedef uchar channel_type;
RGB2HSV_b(int _srccn, int _blueIdx, int _hrange)
: srccn(_srccn), blueIdx(_blueIdx), hrange(_hrange)
{
CV_Assert( hrange == 180 || hrange == 256 );
}
void operator()(const uchar* src, uchar* dst, int n) const
{
int i, bidx = blueIdx, scn = srccn;
const int hsv_shift = 12;
static int sdiv_table[256];
static int hdiv_table180[256];
static int hdiv_table256[256];
static volatile bool initialized = false;
int hr = hrange;
const int* hdiv_table = hr == 180 ? hdiv_table180 : hdiv_table256;
n *= 3;
if( !initialized )
{
sdiv_table[0] = hdiv_table180[0] = hdiv_table256[0] = 0;
for( i = 1; i < 256; i++ )
{
sdiv_table[i] = saturate_cast<int>((255 << hsv_shift)/(1.*i));
hdiv_table180[i] = saturate_cast<int>((180 << hsv_shift)/(6.*i));
hdiv_table256[i] = saturate_cast<int>((256 << hsv_shift)/(6.*i));
}
initialized = true;
}
for( i = 0; i < n; i += 3, src += scn )
{
int b = src[bidx], g = src[1], r = src[bidx^2];
int h, s, v = b;
int vmin = b, diff;
int vr, vg;
CV_CALC_MAX_8U( v, g );
CV_CALC_MAX_8U( v, r );
CV_CALC_MIN_8U( vmin, g );
CV_CALC_MIN_8U( vmin, r );
diff = v - vmin;
vr = v == r ? -1 : 0;
vg = v == g ? -1 : 0;
s = (diff * sdiv_table[v] + (1 << (hsv_shift-1))) >> hsv_shift;
h = (vr & (g - b)) +
(~vr & ((vg & (b - r + 2 * diff)) + ((~vg) & (r - g + 4 * diff))));
h = (h * hdiv_table[diff] + (1 << (hsv_shift-1))) >> hsv_shift;
h += h < 0 ? hr : 0;
struct RGB2HSV_b
{
typedef uchar channel_type;
RGB2HSV_b(int _srccn, int _blueIdx, int _hrange)
: srccn(_srccn), blueIdx(_blueIdx), hrange(_hrange)
{
CV_Assert( hrange == 180 || hrange == 256 );
}
void operator()(const uchar* src, uchar* dst, int n) const
{
int i, bidx = blueIdx, scn = srccn;
const int hsv_shift = 12;
static int sdiv_table[256];
static int hdiv_table180[256];
static int hdiv_table256[256];
static volatile bool initialized = false;
int hr = hrange;
const int* hdiv_table = hr == 180 ? hdiv_table180 : hdiv_table256;
n *= 3;
if( !initialized )
{
sdiv_table[0] = hdiv_table180[0] = hdiv_table256[0] = 0;
for( i = 1; i < 256; i++ )
{
sdiv_table[i] = saturate_cast<int>((255 << hsv_shift)/(1.*i));
hdiv_table180[i] = saturate_cast<int>((180 << hsv_shift)/(6.*i));
hdiv_table256[i] = saturate_cast<int>((256 << hsv_shift)/(6.*i));
}
initialized = true;
}
for( i = 0; i < n; i += 3, src += scn )
{
int b = src[bidx], g = src[1], r = src[bidx^2];
int h, s, v = b;
int vmin = b, diff;
int vr, vg;
CV_CALC_MAX_8U( v, g );
CV_CALC_MAX_8U( v, r );
CV_CALC_MIN_8U( vmin, g );
CV_CALC_MIN_8U( vmin, r );
diff = v - vmin;
vr = v == r ? -1 : 0;
vg = v == g ? -1 : 0;
s = (diff * sdiv_table[v] + (1 << (hsv_shift-1))) >> hsv_shift;
h = (vr & (g - b)) +
(~vr & ((vg & (b - r + 2 * diff)) + ((~vg) & (r - g + 4 * diff))));
h = (h * hdiv_table[diff] + (1 << (hsv_shift-1))) >> hsv_shift;
h += h < 0 ? hr : 0;