I at first think this a beginner' one but when I post there, nobody seems to work it out. So I put it here.

Now, I stuck on another point of convolution.

I have written the following code:

Code :
GLubyte convolutionTable3x3[3][3]=
{
	{1,1,1},
	{1,1,1},
	{1,1,1}
};
 
glPixelStorei(GL_UNPACK_ALIGNMENT,1);
glConvolutionFilter2D(GL_CONVOLUTION_2D,GL_LUMINANCE,3,3,GL_LUMINANCE,GL_UNSIGNED_BYTE,convolutionTable3x3);
glEnable(GL_CONVOLUTION_2D);
glWindowPos2i(0,0);
glDrawPixels(512,512,GL_STENCIL_INDEX,GL_UNSIGNED_BYTE,pboImageStore);
glDisable(GL_CONVOLUTION_2D);

The buffer pboImageStore has some value set 0 and some 2.
The result seems that the stencil buffer has all been set to zero.

Even when I set

Code :
GLubyte convolutionTable3x3[3][3]=
{
	{0,0,0},
	{0,1,0},
	{0,0,0}
};

The result seems that the stencil buffer has all been set to zero.

How can this be so? I just want to do some convolution on my stencil buffer.
Thanks in advance!