图像基本变换--- 平移、旋转、缩放、仿射变换、镜像
图像平移变换函数
[算法说明]
图像平移就是使图像沿水平方向和垂直方向移动。
如果把坐标原点(0,0)平移到点(x0,y0)处，则变换公式为：
(x,y)为原始图像坐标，(x', y')为变换后的图像坐标。而图像中的各个像素点移动了sqrt(x*x + y*y)距离。用矩阵表示为2-(22)：
[函数代码]
///
/// Translation process.
///
/// Source image.
/// Translate value of x.
/// Translate value of y.
///
public static WriteableBitmap TranslationProcess(WriteableBitmap src,int x,int y)////18 平移变换
{
if(src!=null )
{
int w = src.PixelWidth;
int h = src.PixelHeight;
WriteableBitmap translateImage = new WriteableBitmap(w, h);
byte[] temp = src.PixelBuffer.ToArray();
byte[] tempMask = new byte[w * h * 4];
for (int j = 0; j < h; j++)
{
for (int i = 0; i < w; i ++)
{
if (i + x < 0 || i + x >= w || j + y < 0 || j + y >= h)
{
tempMask[i * 4 + j * w * 4] = (byte)0;
tempMask[i * 4 + 1 + j * w * 4] = (byte)0;
tempMask[i * 4 + 2 + j * w * 4] = (byte)0;
}
else
{
tempMask[i * 4 + j * w * 4] = (byte)(temp[(i + x) * 4 + (j + y) * w * 4]);
tempMask[i * 4 + 1 + j * w * 4] = (byte)(temp[(i + x) * 4 + 1 + (j + y) * w * 4]);
tempMask[i * 4 + 2 + j * w * 4] = (byte)(temp[(i + x) * 4 + 2 + (j + y) * w * 4]);
tempMask[i * 4 + 3 + j * w * 4] = (byte)(temp[(i + x) * 4 + 3 + (j + y) * w * 4]);
}
}
}
Stream sTemp = translateImage.PixelBuffer.AsStream();
sTemp.Seek(0, SeekOrigin.Begin);
sTemp.Write(tempMask, 0, w * 4 * h);
return translateImage;
}
else
{
return null;
}
}
[图像效果]
Fig.1原图 Fig.2效果图(x=-20,y=-20)
图像水平镜像函数
[算法说明]
图像水平镜像就是将图像作如下矩阵变换:
[函数代码]
///
/// Horizontal mirror process.
///
/// Source image.
///
public static WriteableBitmap MirrorXProcess(WriteableBitmap src)////19 水平镜像
{
if(src!=null )
{
int w = src.PixelWidth;
int h = src.PixelHeight;
WriteableBitmap mirrorImage = new WriteableBitmap(w,h);
byte[] temp = src.PixelBuffer.ToArray();
byte[] tempMask = new byte[w * h * 4];
for (int j = 0; j < h; j++)
{
for (int i = 0; i < w; i++)
{
tempMask[i * 4 + j * w * 4] = temp[(w - 1 - i) * 4 + j * w * 4];
tempMask[i * 4 + 1 + j * w * 4] = temp[(w - 1 - i) * 4 + 1 + j * w * 4];
tempMask[i * 4 + 2 + j * w * 4] = temp[(w - 1 - i) * 4 + 2 + j * w * 4];
tempMask[i * 4 + 3 + j * w * 4] = temp[(w - 1 - i) * 4 + 3 + j * w * 4];
}
}
Stream sTemp = mirrorImage.PixelBuffer.AsStream();
sTemp.Seek(0, SeekOrigin.Begin);
sTemp.Write(tempMask, 0, w * 4 * h);
return mirrorImage;
}
else
{
return null;
}
}
[图像效果]
Fig.1原图 Fig.2效果图
图像垂直镜像函数
[算法说明]
图像垂直镜像就是将图像作如下矩阵变换:
[函数代码]
///
/// Vertical mirror process.
///
/// Source image.
///
public static WriteableBitmap MirrorYProcess(WriteableBitmap src)////20 垂直镜像
{
if(src!=null )
{
int w = src.PixelWidth;
int h = src.PixelHeight;
WriteableBitmap mirrorImage = new WriteableBitmap(w,h);
byte[] temp = src.PixelBuffer.ToArray();
byte[] tempMask = new byte[w * h * 4];
for (int i = 0; i < w; i++)
{
for (int j = 0; j < h; j++)
{
tempMask[i * 4 + j * w * 4] = temp[i * 4 + (h - 1 - j) * w * 4];
tempMask[i * 4 + 1 + j * w * 4] = temp[i * 4 + 1 + (h - 1 - j) * w * 4];
tempMask[i * 4 + 2 + j * w * 4] = temp[i * 4 + 2 + (h - 1 - j) * w * 4];
tempMask[i * 4 + 3 + j * w * 4] = temp[i * 4 + 3 + (h - 1 - j) * w * 4];
}
}
Stream sTemp = mirrorImage.PixelBuffer.AsStream();
sTemp.Seek(0, SeekOrigin.Begin);
sTemp.Write(tempMask, 0, w * 4 * h);
return mirrorImage;
}
else
{
return null;
}
}
[图像效果]
Fig.1原图 Fig.2效果图
demo 下载： http://www.zealfilter.com/forum.php?mod=viewthread&tid=17&extra=page%3D2