图片的高斯模糊如何做？

[大可山人]

C#中图片的高斯模糊如何做？
我需要可以设置高斯模糊的参数值，就好象PHOTOSHOP中设置Radius值一样。

[大可山人]

顶一下

[大可山人]

晕！我要求最后得到图片的文件效果，而不是仅仅显示。

找到一段C++写的，那位可以翻译为C#的，我不懂C++。

// QGaussFilter.cpp
//
// MFC class to apply Unsharp Mask or Blur to a GDI+ Bitmap.
// Use at your own risk. Comments welcome.
//
// Version 1.1, 02/02/2004:
// Bug resolved in handling of small bitmaps. Thanks to Maik Wiege.
//
// Version 1.0 (c) 2003, Sjaak Priester, Amsterdam.
// mailto:[e-mail]

#include "StdAfx.h"
#include "QGaussFilter.h"
#include "Int.h"

#include <math.h>


const ColorMatrix QGaussFilter::MatRGBtoYUV =
{
0.5f, 0.3086f, -0.1681f, 0, 0,
-0.4407f, 0.6094f, -0.3391f, 0, 0,
-0.0593f, 0.082f, 0.5f, 0, 0,
0, 0, 0, 1, 0,
0.5f, 0, 0.5f, 0, 1
};

const ColorMatrix QGaussFilter::MatYUVtoRGB =
{
1.383f, -0.7002f, 0, 0, 0,
1, 1, 1, 0, 0,
0, -0.247f, 1.836f, 0, 0,
0, 0, 0, 1, 0,
-0.6914f, 0.4736f, -0.918f, 0, 1
};

QGaussFilter::QGaussFilter()
: m_FilterVector(NULL)
, m_Denominator(0)
, m_Dim(0)
, m_MaxDim(51)
, m_bStop(false)
, m_Flags(PlaneAll)
, m_pMsgWnd(NULL)
, m_Message(QM_GAUSSFILTER)
, m_pThread(NULL)
, m_pSource(NULL)
, m_bUnsharpMask(false)
, m_pRect(NULL)
{
}

QGaussFilter::~QGaussFilter(void)
{
Stop();
delete[] m_FilterVector;
delete m_pRect;
}

// Make Unsharp Mask bitmap in a separate worker thread
void QGaussFilter::MakeUnsharpMask(Bitmap * pSource, REAL radius, REAL depth,
CWnd * pMsgWnd, UINT message, Rect * pRect, UINT flags)
{
Stop();
m_pSource = pSource;
m_Radius = radius;
m_Depth = depth;
m_pMsgWnd = pMsgWnd;
m_Message = message;
m_Flags = flags;

delete m_pRect;
if (pRect) m_pRect = pRect->Clone();
else m_pRect = NULL;

m_bUnsharpMask = true;
m_pThread = ::AfxBeginThread(ThreadProc, this);
}

// Make Blur bitmap in a separate worker thread
void QGaussFilter::MakeBlur(Bitmap * pSource, REAL radius,
CWnd * pMsgWnd, UINT message, Rect * pRect, UINT flags)
{
Stop();
m_pSource = pSource;
m_Radius = radius;
m_pMsgWnd = pMsgWnd;
m_Message = message;
m_Flags = flags;

delete m_pRect;
if (pRect) m_pRect = pRect->Clone();
else m_pRect = NULL;

m_bUnsharpMask = false;
m_pThread = ::AfxBeginThread(ThreadProc, this);
}

// Stop calculation of Unsharp Mask or Blur in seperate thread
void QGaussFilter::Stop(void)
{
if (m_pThread)
{
m_bStop = true;
::WaitForSingleObject(m_pThread->m_hThread, INFINITE);
}
}

// Calculate and return Unsharp Mask bitmap
Bitmap * QGaussFilter::GetUnsharpMask(Bitmap * pSrc, REAL radius, REAL depth, Rect * pRect, UINT flags)
{
// Start with blur
Bitmap * pResult = GetBlur(pSrc, radius, pRect, flags, false);
if (pResult)
{
// Subtract blurred bitmap from original to get Unsharp Mask
Rect rcSrc(0, 0, pSrc->GetWidth(), pSrc->GetHeight());
if (pRect) rcSrc.Intersect(* pRect);

BitmapData dataSrc;
Status s = pSrc->LockBits(& rcSrc, ImageLockModeRead,
PixelFormat24bppRGB, & dataSrc);
if (s != Ok)
{
delete pResult;
return NULL;
}

Rect rcResult(0, 0, pResult->GetWidth(), pResult->GetHeight());

BitmapData dataResult;
s = pResult->LockBits(& rcResult, ImageLockModeRead | ImageLockModeWrite,
PixelFormat24bppRGB, & dataResult);
if (s != Ok)
{
pSrc->UnlockBits(& dataSrc);
delete pResult;
return NULL;
}

const int nPlanes = 3;

// On modern systems, the difference is not big, but real math is still somewhat
// slower than integer math. But if this ever changes, you may define REAL_MATH.
#ifdef REAL_MATH
REAL depthPlus = depth + 1.0f;
#else
int denom = 10000; // use an arbitrary denominator, not too small
int dpt = Int((REAL) denom * depth);
int dptplus = dpt + denom;
#endif

BYTE * pStartSrc = (BYTE *) dataSrc.Scan0;
BYTE * pStartResult = (BYTE *) dataResult.Scan0;

for (int plane = 0; plane < nPlanes; plane++) // loop through color planes
{
bool bThisPlane = (flags & 1) != 0;
flags >>= 1;

BYTE * pLineSrc = pStartSrc;
BYTE * pLineResult = pStartResult;

if (bThisPlane)
{
for (UINT line = 0; line < dataResult.Height; line++) // loop through lines
{
BYTE * pPixelSrc = pLineSrc;
BYTE * pPixelResult = pLineResult;

for (UINT pxl = 0; pxl < dataResult.Width; pxl++) // loop through pixels
{
#ifdef REAL_MATH
REAL v = depthPlus * *pPixelSrc - depth * *pPixelResult;
if (v > 255.0f) v = 255.0f;
if (v < 0.0f) v = 0.0f;
#else
int v = dptplus * *pPixelSrc - dpt * *pPixelResult;
v /= denom;

// Clipping is very essential here. for large values of depth
// (> 5.0f) more than half of the pixel values are clipped.
if (v > 255) v = 255;
if (v < 0) v = 0;
#endif
* pPixelResult = (BYTE) v;
pPixelSrc += nPlanes;
pPixelResult += nPlanes;
}
if (m_bStop) break;
pLineSrc += dataSrc.Stride;
pLineResult += dataResult.Stride;
}
}
else // no subtraction, just copy
{
for (UINT line = 0; line < dataResult.Height; line++) // loop through lines
{
BYTE * pPixelSrc = pLineSrc;
BYTE * pPixelResult = pLineResult;

for (UINT pxl = 0; pxl < dataResult.Width; pxl++)
{
* pPixelResult = * pPixelSrc;
pPixelSrc += nPlanes;
pPixelResult += nPlanes;
}

if (m_bStop) break;
pLineSrc += dataSrc.Stride;
pLineResult += dataResult.Stride;
} // next line
}

if (m_bStop) break;
pStartSrc++;
pStartResult++;
} // next plane

pResult->UnlockBits(& dataResult);
pSrc->UnlockBits(& dataSrc);

if (m_bStop)
{
delete pResult;
pResult = NULL;
}
}
return pResult;
}

[大可山人]

// Calculate and return Blur bitmap
Bitmap * QGaussFilter::GetBlur(Bitmap * pSrc, REAL radius, Rect * pRect, UINT flags, bool bCopy)
{
if (! SetRadius(radius)) return NULL;

// Convolute in horizontal direction
Bitmap * pTemp = ConvoluteDimension(pSrc, pRect, flags, true, bCopy);

if (! pTemp) return NULL;

// Convolute the result in vertical direction
Bitmap * pResult = ConvoluteDimension(pTemp, pRect, flags, false, bCopy);
delete pTemp;
return pResult;
}

bool QGaussFilter::SetRadius(REAL radius)
{
delete[] m_FilterVector;
m_FilterVector = 0;
m_Dim = 0;

// d is the effective diameter in pixels; all weight factors outside d are assumed
// to be zero. The factor 5.0 is somewhat arbitrary; a value between 4.0 and 6.0
// is generally recommended.
UINT d = Int(5.0f * radius + 1.0f);

if (d > m_MaxDim) return false; // radius to great
d |= 1; // must be odd
m_Dim = d;

if (m_Dim == 0) return true; // radius 0 is acceptable; effectively no convolution

m_FilterVector = new int[m_Dim];
d /= 2;

REAL num = 2 * radius * radius;
REAL f = expf(d * d / num);
m_Denominator = Int(f);

m_FilterVector[d] = m_Denominator;

for (UINT i = 1; i <= d; i++)
{
int i2 = - (int)(i * i);
int v = Int(f * expf(i2 / num));
m_FilterVector[d - i] = v;
m_FilterVector[d + i] = v;
m_Denominator += 2 * v;
}

return true;
}

// This is the workhorse of QGaussFilter. It calculates the convolution either in
// horizontal direction, or in vertical direction (depending on bHorizontal).
Bitmap * QGaussFilter::ConvoluteDimension(Bitmap * pSrc, Rect * pRect, UINT flags,
bool bHorizontal, bool bCopy)
{
Rect rc(0, 0, pSrc->GetWidth(), pSrc->GetHeight());
if (pRect) rc.Intersect(* pRect);

if (m_Dim <= 1) return pSrc->Clone(rc, PixelFormat24bppRGB);
// m_Dim == 0 or 1: effectively no convolution, just return a copy

// LockBits on source
BitmapData dataSrc;
Status s = pSrc->LockBits(& rc, ImageLockModeRead, PixelFormat24bppRGB, & dataSrc);
if (s != Ok) return NULL;

UINT d = m_Dim / 2;
const int nPlanes = 3;

Bitmap * pDest = new Bitmap(rc.Width, rc.Height, PixelFormat24bppRGB);
if (! pDest)
{
pSrc->UnlockBits(& dataSrc);
return NULL;
}

// LockBits on destination
rc.X = 0;
rc.Y = 0;
BitmapData dataDest;
s = pDest->LockBits(& rc, ImageLockModeRead | ImageLockModeWrite,
PixelFormat24bppRGB, & dataDest);

if (s != Ok)
{
pSrc->UnlockBits(& dataSrc);
delete pDest;
return NULL;
}

BYTE * pStartSrc = (BYTE *) dataSrc.Scan0;
BYTE * pStartDest = (BYTE *) dataDest.Scan0;

UINT nLines; // number of lines (horizontal or vertical)
UINT nPixels; // number of pixels per line
UINT dPixelSrc; // pixel step in source
UINT dPixelDest; // pixel step in destination
UINT dLineSrc; // line step in source
UINT dLineDest; // line step in destination

if (bHorizontal)
{
nLines = dataDest.Height;
nPixels = dataDest.Width;
dPixelSrc = nPlanes;
dPixelDest = nPlanes;
dLineSrc = dataSrc.Stride;
dLineDest = dataDest.Stride;
}
else
{
nLines = dataDest.Width;
nPixels = dataDest.Height;
dPixelSrc = dataSrc.Stride;
dPixelDest = dataDest.Stride;
dLineSrc = nPlanes;
dLineDest = nPlanes;
}

// This line added in version 1.1: avoid overrun in small bitmaps.
if (d > nPixels / 2) d = nPixels / 2;

for (int plane = 0; plane < nPlanes; plane++) // loop through color planes
{
bool bThisPlane = (flags & 1) != 0;

flags >>= 1;

BYTE * pLineSrc = pStartSrc;
BYTE * pLineDest = pStartDest;

if (bThisPlane)
{
for (UINT line = 0; line < nLines; line++) // loop through lines
{
BYTE * pPixelDest = pLineDest;

for (UINT pxl = 0; pxl < d; pxl++) // loop through pixels in left/top margin
{
int * pFactors = m_FilterVector + d - pxl;

UINT xEnd = pxl + d;
if (xEnd > nPixels) xEnd = nPixels;

int denom = 0;
int sum = 0;

BYTE * pPixelSrc = pLineSrc;

for (UINT x = 0; x < xEnd; x++)
{
denom += *pFactors;
sum += *pFactors++ * *pPixelSrc;
pPixelSrc += dPixelSrc;
}

if (denom) sum /= denom;
* pPixelDest = (BYTE) sum;

pPixelDest += dPixelDest;
}

for (pxl = d; pxl < nPixels - d; pxl++) // loop through pixels in main area
{
int * pFactors = m_FilterVector;
int sum = 0;

UINT xBegin = pxl - d;
BYTE * pPixelSrc = & pLineSrc[xBegin * dPixelSrc];

for (UINT x = xBegin; x <= pxl + d; x++)
{
sum += *pFactors++ * *pPixelSrc;
pPixelSrc += dPixelSrc;
}

sum /= m_Denominator;
* pPixelDest = (BYTE) sum;

pPixelDest += dPixelDest;
}

for (pxl = nPixels - d; pxl < nPixels; pxl++)
// loop through pixels in right/bottom margin
{
int * pFactors = m_FilterVector;
int denom = 0;
int sum = 0;

int xBegin = pxl - d;
if (xBegin < 0) xBegin = 0;
BYTE * pPixelSrc = & pLineSrc[xBegin * dPixelSrc];

for (UINT x = xBegin; x < nPixels; x++)
{
denom += *pFactors;
sum += *pFactors++ * *pPixelSrc;
pPixelSrc += dPixelSrc;
}

if (denom) sum /= denom;

* pPixelDest = (BYTE) sum;

pPixelDest += dPixelDest;
}

if (m_bStop) break;
pLineSrc += dLineSrc;
pLineDest += dLineDest;
} // next line

if (m_bStop) break;
}
else if (bCopy) // no convolution, just copy
{
for (UINT line = 0; line < nLines; line++) // loop through lines
{
BYTE * pPixelSrc = pLineSrc;
BYTE * pPixelDest = pLineDest;

for (UINT pxl = 0; pxl < nPixels; pxl++) // loop through pixels
{
* pPixelDest = * pPixelSrc;
pPixelSrc += dPixelSrc;
pPixelDest += dPixelDest;
}

if (m_bStop) break;
pLineSrc += dLineSrc;
pLineDest += dLineDest;
} // next line

if (m_bStop) break;
}

pStartSrc++;
pStartDest++;
} // next plane

pDest->UnlockBits(& dataDest);
pSrc->UnlockBits(& dataSrc);

if (m_bStop)
{
delete pDest;
pDest = NULL;
}
return pDest;
}

/* static */
UINT QGaussFilter::ThreadProc(LPVOID pParam)
{
QGaussFilter * pThis = (QGaussFilter *) pParam;

ASSERT(pThis->m_pMsgWnd);
Bitmap * pResult = pThis->Calculate();
pThis->m_pThread = NULL;
pThis->m_bStop = false;

pThis->Notify(pResult);
return 0;
}

// Called by ThreadProc
Bitmap * QGaussFilter::Calculate(void)
{
m_bStop = false;
if (m_bUnsharpMask) return GetUnsharpMask(m_pSource, m_Radius, m_Depth, m_pRect, m_Flags);
else return GetBlur(m_pSource, m_Radius, m_pRect, m_Flags);
}

// Called by ThreadProc
void QGaussFilter::Notify(Bitmap * pResult)
{
if (pResult && m_pMsgWnd) m_pMsgWnd->PostMessage(m_Message, 0, (LPARAM) pResult);
}

/* static */
void QGaussFilter::ToColorSpace(Bitmap * pBitmap, const ColorMatrix& mat)
{
Rect rc(0, 0, pBitmap->GetWidth(), pBitmap->GetHeight());

ImageAttributes attr;
attr.SetColorMatrix(& mat);

// Although undocumented, it seems perfectly legal to draw a bitmap on itself.
Graphics g(pBitmap);
g.DrawImage(pBitmap,
rc,
0, 0, rc.Width, rc.Height,
UnitPixel,
& attr);
}

[大可山人]

如果需要以下头文件，请留下Email，MSN或QQ号。
#include "StdAfx.h"
#include "QGaussFilter.h"
#include "Int.h"
#include <math.h>
可以共同解决此问题

[fkphp]

用CSS可以实现

[alliat]

CSS中有这样的滤镜

[johnsunac]

牛人们都到哪里去了？

[xiaohutushen]

up

[paul8765]

就用photoshop做算了。

[大可山人]

楼上没有研究精神哟

[大可山人]

再顶一下。