实作色彩系统转换程序 (VB 6.0)
实作色彩系统转换程序 (VB 6.0)
下载原始码及执行档：
介绍
RGB转HSI
HSI转RGB
当0°≦H<120°时，B值最小，因此如下式：
当120°<H≦240°时。
CMYK转RGB
tCMYK = {C,M,Y,K}
转换成三分色
tCMY = {C',M',Y'} = {C(1 - K) + K,M(1 - K) + K,Y(1 - K) + K}
然后再转换成RGB
tRGB = {R,G,B} = {1 - C',1 - M',1 - Y'}
同理结果如下：
tRGB = {1 - (C(1 - K) + K),1 - (M(1 - K) + K),1 - (Y(1 - K) + K)} =
{1 - C(1 - K) - K,1 - M(1 - K) - K,1 - Y(1 - K) - K}
RGB转CMYK
tRGB = {R,G,B}
先转换成三分色
tCMY = {C',M',Y'} = {1 - R,1 - G,1 - B}
if min{C',M',Y'} = 1
tCMYK = {0,0,0,1}
再转换成四分色
K = min{C',M',Y'}
RGB转YUV
Y=0.299R+0.587G+0.114B
U=0.493(B-Y)=0.439(-0.29R-0.587G+0.886B)
V=0.877(0.701R-0.587G-0.114B)
YUV与RGB关系如下：
RGB与YUV关系如下：
将其正规化，可以将RGB和YUV都在0到255之间转换。所以可以采用下列的程序：
R = Y + (1.4075 *
(V - 128))
G = Y - (0.3455 *
(U - 128) - (0.7169 * (V - 128))
B = Y + (1.7790 *
(U - 128)
Y = R * .299 + G
* .587 + B * .114
U = R * -.169 + G
* -.332 + B * .500 + 128
V = R * .500 + G
* -.419 + B * -.0813 + 128
YIQ与RGB之间的关系如下：
RGB与YIQ之间的关系如下：
YCbCr与RGB的关系如下：
RGB与YCbCr关系如下：
环境
操作系统：Microsoft Windows 7 (64 bit)
开发工具：Microsoft Visual Basic 6.0
用法
'设定所有变量必须宣告才能使用
Option
Explicit
Private
Sub Form_Load()
'加载影像
Picture1.Picture = LoadPicture(App.Path
& "\Lai, Tai-Yu.bmp")
'设定picture1计算单位为像素
Picture1.ScaleMode = 3
'设定picture1自动重绘有效
Picture1.AutoRedraw = True
End Sub
'Picture1鼠标移动事件
Private
Sub Picture1_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As
Single)
'宣告RGB变量
Dim intR, intG, intB
'获取RGB值
intR = (Picture1.Point(X, Y) And &HFF)
intG = (Picture1.Point(X, Y) \ &H100)
And &HFF
intB = (Picture1.Point(X, Y) \ &H10000)
And &HFF
'显示RGB值
labRGB_R.Caption = "R = " &
intR
labRGB_G.Caption = "G = " &
intG
labRGB_B.Caption = "B = " &
intB
'宣告转换至HSV所需变量
Dim intS
Dim dobH, dobS, dobV
Dim intMax, intMin, intD
'开始转换HSV
intMin = min(intR, intG, intB)
intMax = max(intR, intG, intB)
dobV = intMax / 255
intD = intMax - intMin
If (intR = intG) And (intG = intB) Then
dobH = 0
Else
dobH = Arccos((0.5 * ((intR - intG) +
(intR - intB))) / _
(Sqr(((intR - intG) * (intR -
intG) + (intR - intB) * (intG - intB)))))
End If
If intB > intG Then
dobH = 2 * 3.1415 - dobH
End If
If intMax > 0 Then
dobS = intD / intMax
Else
dobS = 0
End If
'显示HSV数值
labHSV_H.Caption = "H = " &
Format(dobH, "0.##")
labHSV_S.Caption = "S = " &
Format(dobS, "0.##")
labHSV_V.Caption = "V = " &
Format(dobV, "0.##")
'宣告YUV变量
Dim YUV_Y, YUV_U, YUV_V
'开始转换，矩阵相乘
YUV_Y = 0.299 * intR + 0.587 * intG + 0.114
* intB
YUV_U = 0.439 * (-0.29 * intR - 0.587 *
intG + 0.886 * intB)
YUV_V = 0.877 * (0.701 * intR - 0.587 *
intG - 0.114 * intB)
'显示YUV数值
labYUV_Y.Caption = "Y = " &
Format(YUV_Y, "0.##")
labYUV_U.Caption = "U = " &
Format(YUV_U, "0.##")
labYUV_V.Caption = "V = " &
Format(YUV_V, "0.##")
'宣告YIQ变量
Dim YIQ_Y, YIQ_I, YIQ_Q
'开始转换，矩阵相乘
YIQ_Y = 0.299 * intR + 0.587 * intG + 0.114
* intB
YIQ_I = 0.596 * intR + (-0.275 * intG) +
(-0.321 * intB)
YIQ_Q = 0.212 * intR + (-0.523 * intG) +
0.311 * intB
'显示YIQ数值
labYIQ_Y.Caption = "Y = " &
Format(YIQ_Y, "0.##")
labYIQ_I.Caption = "I = " &
Format(YIQ_I, "0.##")
labYIQ_Q.Caption = "Q = " &
Format(YIQ_Q, "0.##")
'宣告YCbCr变量
Dim YCbCr_Y, YCbCr_Cb, YCbCr_Cr
'开始转换，矩阵相乘
YCbCr_Y = 0.299 * intR + 0.587 * intG +
0.114 * intB
YCbCr_Cb = (-0.1687 * intR) + (-0.3313 *
intG) + 0.5 * intB + 128
YCbCr_Cr = 0.5 * intR + (-0.4187 * intG) +
(-0.0813 * intB) + 128
'显示YCbCr数值
labYCbCr_Y.Caption = "Y = " &
Format(YCbCr_Y, "0.##")
labYCbCr_Cb.Caption = "Cb = "
& Format(YCbCr_Cb, "0.##")
labYCbCr_Cr.Caption = "Cr = "
& Format(YCbCr_Cr, "0.##")
'宣告CMYK变量
Dim CMYK_C, CMYK_M, CMYK_Y, CMYK_K
'开始转换CMYK
CMYK_C = 255 - intR
CMYK_M = 255 - intG
CMYK_Y = 255 - intB
If CMYK_C < CMYK_M Then
CMYK_K = CMYK_C
Else
CMYK_K = CMYK_M
End If
If CMYK_Y < CMYK_K Then
CMYK_K = CMYK_Y
End If
If CMYK_K > 0 Then
CMYK_C = CMYK_C - CMYK_K
CMYK_M = CMYK_M - CMYK_K
CMYK_Y = CMYK_Y - CMYK_K
End If
'显示CMYK数值
labCMYK_C.Caption = "C = " &
Format(CMYK_C, "0.##")
labCMYK_M.Caption = "M = " &
Format(CMYK_M, "0.##")
labCMYK_Y.Caption = "Y = " & Format(CMYK_Y, "0.##")
labCMYK_K.Caption = "K = " &
Format(CMYK_K, "0.##")
End Sub
'寻找最小值函式
Private Function min(intA As Variant, intB As
Variant, intC As Variant)
'宣告最小值变量
Dim
intMin As Integer
'A若小于等于B
If
intA <= intB Then
'最小值为A
intMin = intA
'反之
Else
'最小值为B
intMin = intB
End
If
'最小值变数大于C
If
intMin > intC Then
'最小值设定为C
intMin = intC
End
If
'回传最小值
min
= intMin
'结束函式
End Function
'搜寻最大值函式
Private Function max(intA As Variant, intB As
Variant, intC As Variant)
'宣告最大值变量
Dim
intMax As Integer
'当A值大于等于B值
If
intA >= intB Then
'最大值为A
intMax = intA
'反之
Else
'最大值为B
intMax = intB
End
If
'当最大值变数小于C
If
intMax < intC Then
'则最大值变量设定为C
intMax = intC
End
If
'回传最大值
max
= intMax
'结束函式
End Function
' Inverse Cosine (反余弦)函式
Private Function Arccos(X)
'避免零除的情况
On
Error Resume Next
' Inverse Cosine (反余弦)函式
Arccos = Atn(-X / Sqr(-X * X + 1)) + 2 * Atn(1)
'结束函式
End Function
例外
1. 如果执行档不能执行，请先安装vbrun60sp6.exe。
参考
致谢
感谢 (维基自由百科) 提供的知识。
