#define labXr_32f 0.433953f /* = xyzXr_32f / 0.950456 */

#define labXg_32f 0.376219f /* = xyzXg_32f / 0.950456 */

#define labXb_32f 0.189828f /* = xyzXb_32f / 0.950456 */

#define labYr_32f 0.212671f /* = xyzYr_32f */

#define labYg_32f 0.715160f /* = xyzYg_32f */

#define labYb_32f 0.072169f /* = xyzYb_32f */

#define labZr_32f 0.017758f /* = xyzZr_32f / 1.088754 */

#define labZg_32f 0.109477f /* = xyzZg_32f / 1.088754 */

#define labZb_32f 0.872766f /* = xyzZb_32f / 1.088754 */

#define labRx_32f 3.0799327f /* = xyzRx_32f * 0.950456 */

#define labRy_32f (-1.53715f) /* = xyzRy_32f */

#define labRz_32f (-0.542782f)/* = xyzRz_32f * 1.088754 */

#define labGx_32f (-0.921235f)/* = xyzGx_32f * 0.950456 */

#define labGy_32f 1.875991f /* = xyzGy_32f */

#define labGz_32f 0.04524426f /* = xyzGz_32f * 1.088754 */

#define labBx_32f 0.0528909755f /* = xyzBx_32f * 0.950456 */

#define labBy_32f (-0.204043f) /* = xyzBy_32f */

#define labBz_32f 1.15115158f /* = xyzBz_32f * 1.088754 */

#define labT_32f 0.008856f

#define labSmallScale_32f 7.787f

#define labSmallShift_32f 0.13793103448275862f /* 16/116 */

#define labLScale_32f 116.f

#define labLShift_32f 16.f

#define labLScale2_32f 903.3f

typedef union Cv32suf

{

int i;

unsigned u;

float f;

}

Cv32suf;

#define cvCbrt cuCubeRoot

DEVICE float cuCubeRoot( float value )

{

return __powf(value,1.0f/3.0f);

}

DEVICE void cuCvRGBtoLab( unsigned char pixR, unsigned char pixG, unsigned char pixB,

float4 *g_result)

{

float4 lab;

float b = pixB/255.0, g = pixG/255.0, r = pixR/255.0;

float x_, y_, z;

x_ = b*labXb_32f + g*labXg_32f + r*labXr_32f;

y_ = b*labYb_32f + g*labYg_32f + r*labYr_32f;

z = b*labZb_32f + g*labZg_32f + r*labZr_32f;

if( x_ > labT_32f )

x_ = cvCbrt(x_);

else

x_ = x_*labSmallScale_32f + labSmallShift_32f;

if( z > labT_32f )

z = cvCbrt(z);

else

z = z*labSmallScale_32f + labSmallShift_32f;

if( y_ > labT_32f )

{

y_ = cvCbrt(y_);

lab.x = y_*labLScale_32f - labLShift_32f; // L

}

else

{

lab.x = y_*labLScale2_32f; // L

y_ = y_*labSmallScale_32f + labSmallShift_32f;

}

lab.y = 500.f*(x_ - y_); // a

lab.z = 200.f*(y_ - z); // b

*g_result = lab;

}

DEVICE void cuCvLabtoRGB( float L, float a, float b,

unsigned char *r_, unsigned char *g_, unsigned char *b_) {

float x, y, z;

L = (L + labLShift_32f)*(1.f/labLScale_32f);

x = (L + a*0.002f);

z = (L - b*0.005f);

y = L*L*L;

x = x*x*x;

z = z*z*z;

float g, r;

b = x*labBx_32f + y*labBy_32f + z*labBz_32f;

*b_ = ROUND(b*255);

g = x*labGx_32f + y*labGy_32f + z*labGz_32f;

*g_ = ROUND(g*255);

r = x*labRx_32f + y*labRy_32f + z*labRz_32f;

*r_ = ROUND(r*255);

}