PS的HSL控制算法是什么，请教高手

[花熊]

我在网上搜到这些：Photoshop中HSL调节滤镜的原理。一个RGB格式的图片，通过HSL颜色格式，可以将图片的整体色调进行调节。比如我们要调节 Hue色调值，增加50。首先，取出每个点的RGB颜色值，转换为HSL，将得到的Hue值加上50，然后转换到RGB颜色，覆盖原来点的颜色。就这样，将所有的点都做一回合的互转，就能够将整个图片的色调进行调整。

所以做了一个DEMO测试，DEMO上三个滑块:H,S,L,H的范围：[-180， 180]， S和L的范围[0, 200]，
1.取得滑块三个值m_H,m_S, m_L
2.取出每个点的RGB颜色值，转换为HSL，为HSor,SSor, LSor
HSor += m_H;
SSor = (SSor*m_L/100.0f);
LSor = (LSor*m_S/100.0f);
<自己估计这里算法控制不对，求指点>
3.转换回RGB.

结果滑动渐变不对，求高手指点，
以下为自己的RGB和HSL转换代码

void RgbWithHsl_Hgy::RgbToHsl_Hgy(void)
{
	double mn, mx; 
	int	   major;

	if (red < green)
	{
		mn = red; 
		mx = green;
		major = Green;
	}
	else
	{
		mn = green;
		mx = red; 
		major = Red;
	}

	if (blue < mn)
	{
		mn = blue;
	}
	else if (blue > mx)
	{
		mx = blue;
		major = Blue;
	}

	if (mn == mx) 
	{
		lightness    = mn/255;
		saturation   = 0;
		hue          = 0; 
	}   
	else 
	{ 
		lightness = (mn+mx) / 510;

		if (lightness <= 0.5)
		{
			saturation = (mx-mn) / (mn+mx); 
		}
		else
		{
			saturation = (mx-mn) / (510-mn-mx);
		}

		switch (major)
		{
		case Red:
			hue = (green-blue) * 60 / (mx-mn) + 360; 
			break;

		case Green: 
			hue = (blue-red) * 60  / (mx-mn) + 120;  
			break;

		case Blue : hue = (red-green) * 60 / (mx-mn) + 240;
			break;
		}

		if (hue >= 360)
		{
			hue = hue - 360;
		}
	}
}

unsigned char Value(double m1, double m2, double h)
{
	while (h >= 360) 
	{
		h -= 360;
	}
	while (h < 0) 
	{
		h += 360;
	}

	if (h < 60) 
	{
		m1 = m1 + (m2 - m1) * h / 60;   
	}
	else if (h < 180) 
	{
		m1 = m2;
	}
	else if (h < 240) 
	{
		m1 = m1 + (m2 - m1) * (240 - h) / 60;  
	}

	return (unsigned char)(m1 * 255);
}

void RgbWithHsl_Hgy::HslToRgb_Hgy(void)
{
	if (saturation == 0)
	{
		red = green = blue = (unsigned char) (lightness*255);
	}
	else
	{
		double m1, m2;

		if (lightness <= 0.5)
		{
			m2 = lightness + lightness * saturation;  
		}
		else       
		{
			m2 = lightness + saturation - lightness * saturation;
		}

		m1 = 2 * lightness - m2;   

		red   = Value(m1, m2, hue + 120);   
		green = Value(m1, m2, hue);
		blue  = Value(m1, m2, hue - 120);
	}
}

越详细越好，谢谢。求高手.

[花熊]

自己解决了，网页故障，发了两次贴，杯具，散分

[morrist1987]

多结点分给我。。。多谢楼主

[jixiang1983]

顶......