CV_<bit_depth>(S|U|F)C<number_of_channels>
1--bit_depth---比特数---代表8bite,16bites,32bites,64bites---举个例子吧--比如说,如
如果你现在创建了一个存储--灰度图片的Mat对象,这个图像的大小为宽100,高100,那么,现在这张
灰度图片中有10000个像素点,它每一个像素点在内存空间所占的空间大小是8bite,8位--所以它对
应的就是CV_8
2--S|U|F--S--代表---signed int---有符号整形
U--代表--unsigned int--无符号整形
F--代表--float---------单精度浮点型
3--C<number_of_channels>----代表---一张图片的通道数,比如:
1--灰度图片--grayImg---是--单通道图像
2--RGB彩色图像---------是--3通道图像
3--带Alph通道的RGB图像--是--4通道图像
//【1】CV_8UC1---则可以创建----8位无符号的单通道---灰度图片------grayImg
#define CV_8UC1 CV_MAKETYPE(CV_8U,1)
#define CV_8UC2 CV_MAKETYPE(CV_8U,2)
//【2】CV_8UC3---则可以创建----8位无符号的三通道---RGB彩色图像---colorImg
#define CV_8UC3 CV_MAKETYPE(CV_8U,3)
//【3】CV_8UC4--则可以创建-----8位无符号的四通道---带透明色的RGB图像
#define CV_8UC4 CV_MAKETYPE(CV_8U,4)
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;
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 );
uchar diff = saturate_cast<uchar>(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;
dst[i] = saturate_cast<uchar>(h);
dst[i+1] = (uchar)s;
dst[i+2] = (uchar)v;
}
}
int srccn, blueIdx, hrange;
};
struct RGB2HSV_f
{
typedef float channel_type;
RGB2HSV_f(int _srccn, int _blueIdx, float _hrange)
: srccn(_srccn), blueIdx(_blueIdx), hrange(_hrange) {}
void operator()(const float* src, float* dst, int n) const
{
int i, bidx = blueIdx, scn = srccn;
float hscale = hrange*(1.f/360.f);
n *= 3;
for( i = 0; i < n; i += 3, src += scn )
{
float b = src[bidx], g = src[1], r = src[bidx^2];
float h, s, v;
float vmin, diff;
v = vmin = r;
if( v < g ) v = g;
if( v < b ) v = b;
if( vmin > g ) vmin = g;
if( vmin > b ) vmin = b;
diff = v - vmin;
s = diff/(float)(fabs(v) + FLT_EPSILON);
diff = (float)(60./(diff + FLT_EPSILON));
if( v == r )
h = (g - b)*diff;
else if( v == g )
h = (b - r)*diff + 120.f;
else
h = (r - g)*diff + 240.f;
if( h < 0 ) h += 360.f;
dst[i] = h*hscale;
dst[i+1] = s;
dst[i+2] = v;
}
}
int srccn, blueIdx;
float hrange;
};
#define FLT_EPSILON 1.192092896e-07F // smallest such that 1.0+FLT_EPSILON != 1.0
/* helper tables */
extern const uchar icvSaturate8u_cv[];
#define CV_FAST_CAST_8U(t) ( (-256 <= (t) && (t) <= 512) ? icvSaturate8u_cv[(t)+256] : 0 )
#define CV_CALC_MIN_8U(a,b) (a) -= CV_FAST_CAST_8U((a) - (b))
#define CV_CALC_MAX_8U(a,b) (a) += CV_FAST_CAST_8U((b) - (a))