Hey, Im trying to get a gaussian blur effect to work on a video source. I currently have it up and running, but i dont think i understand how its ment to work, all refrences i find use alot of greek symbols which i do not understand. But through some examples and source code i am using this..

float dif = 159;

float gaussianMask[5][5];

gaussianMask[0][0] = 2/dif; gaussianMask[0][1] =  4/dif; gaussianMask[0][2] =  5/dif; gaussianMask[0][3] =  4/dif; gaussianMask[0][4] = 2/dif;	
	gaussianMask[1][0] = 4/dif; gaussianMask[1][1] =  9/dif; gaussianMask[1][2] = 12/dif; gaussianMask[1][3] =  9/dif; gaussianMask[1][4] = 4/dif;	
	gaussianMask[2][0] = 5/dif; gaussianMask[2][1] = 12/dif; gaussianMask[2][2] = 15/dif; gaussianMask[2][3] = 12/dif; gaussianMask[2][4] = 2/dif;	
	gaussianMask[3][0] = 4/dif; gaussianMask[3][1] =  9/dif; gaussianMask[3][2] = 12/dif; gaussianMask[3][3] =  9/dif; gaussianMask[3][4] = 4/dif;	
	gaussianMask[4][0] = 2/dif; gaussianMask[4][1] =  4/dif; gaussianMask[4][2] =  5/dif; gaussianMask[4][3] =  4/dif; gaussianMask[4][4] = 2/dif;	

This is a 5x5 mask i am using - i then multiply each value to a each corisponding pixel in a 5x5 area, and then add it to the original pixel

And what i end up with is a nice light show :P

Im not asking for a full explanation of all the theory on this, as i am currently reading up on it anyways, but simply want a summary of what needs to be done, so i know im going in the right direction. Or just some clarification

Thanks for any help ;)

This is a 5x5 mask i am using - i then multiply each value to a each corisponding pixel in a 5x5 area, and then add it to the original pixel

This sounds very suspicious. You should be writing to a separate buffer (otherwise you will get behavior depending on the order in which you process pixels) and you should be summing up the weighted values and write the sum to a single pixel

Yea, this is the part i had seen while reading up on it and was unsure of, i have to get an average, but was unsure what to do with the average. Am i ment to average all of these results for the 5x5 area, and then apply it to each of pixel in the sample area ?

This is how im obtaining the sample: (excuse the messy code ;) )

for( int loop = 0; loop < m_width*(m_height*3); loop+=5 ) {
	
	data[loop+0] += ( data[loop+0] * gaussianMask[0][0] );
	data[loop+1] += ( data[loop+1] * gaussianMask[0][1] );
	data[loop+2] += ( data[loop+2] * gaussianMask[0][2] );
	data[loop+3] += ( data[loop+3] * gaussianMask[0][3] );
	data[loop+4] += ( data[loop+4] * gaussianMask[0][4] );
	
	data[loop+0+offset] += ( data[loop+0+offset] * gaussianMask[1][0] );
	data[loop+1+offset] += ( data[loop+1+offset] * gaussianMask[1][1] );
	data[loop+2+offset] += ( data[loop+2+offset] * gaussianMask[1][2] );
	data[loop+3+offset] += ( data[loop+3+offset] * gaussianMask[1][3] );
	data[loop+4+offset] += ( data[loop+4+offset] * gaussianMask[1][4] );
	
	data[loop+0+(offset*2)] += ( data[loop+0+(offset*2)] * gaussianMask[2][0] );
	data[loop+1+(offset*2)] += ( data[loop+0+(offset*2)] * gaussianMask[2][1] );
	data[loop+2+(offset*2)] += ( data[loop+0+(offset*2)] * gaussianMask[2][2] );
	data[loop+3+(offset*2)] += ( data[loop+0+(offset*2)] * gaussianMask[2][3] );
	data[loop+4+(offset*2)] += ( data[loop+0+(offset*2)] * gaussianMask[2][4] );

	data[loop+0+(offset*3)] += ( data[loop+0+(offset*3)] * gaussianMask[3][0] );
	data[loop+1+(offset*3)] += ( data[loop+0+(offset*3)] * gaussianMask[3][1] );
	data[loop+2+(offset*3)] += ( data[loop+0+(offset*3)] * gaussianMask[3][2] );
	data[loop+3+(offset*3)] += ( data[loop+0+(offset*3)] * gaussianMask[3][3] );
	data[loop+4+(offset*3)] += ( data[loop+0+(offset*3)] * gaussianMask[3][4] );

	data[loop+0+(offset*4)] += ( data[loop+0+(offset*4)] * gaussianMask[4][0] );
	data[loop+1+(offset*4)] += ( data[loop+0+(offset*4)] * gaussianMask[4][1] );
	data[loop+2+(offset*4)] += ( data[loop+0+(offset*4)] * gaussianMask[4][2] );
	data[loop+3+(offset*4)] += ( data[loop+0+(offset*4)] * gaussianMask[4][3] );
	data[loop+4+(offset*4)] += ( data[loop+0+(offset*4)] * gaussianMask[4][4] );
	}

Where data is a unsigned char array of the pixel colors.

I know now that this isint right, and had tought this was causing my crazy colors because its just increasing the color values really.

Thanks for the help lads !

One follow up question. The character array is stored in pixels .. r,g,b,r,g,b,r,g,b

Is the mask applied to each color or each pixel ? as in.. should it be - r * gaussianMask[0][0] g * gaussianMask[0][1] b *gaussianMask[0][2]

or r * gaussianMask[0][0] g * gaussianMask[0][0] b * gaussianMask[0][0].. r * gaussianMask[0][1] g * gaussianMask[0][1] b * gaussianMask[0][1]