int coeff_id=0;  //index used to cycle through the different sets of coefficients

    //note - the 0th entry here is multiplied by two to avoid the 0.5's

    alt_8   C_m1_m1[7]  = {2, 1, 1, 1,-1, 0,-1};  //coeffs0 byte 1
    alt_8   C_m1_0[7]   = {2, 1, 1,-2,-1,-1,-2};  //coeffs0 byte 0
    alt_8   C_m1_p1[7]  = {2, 1, 2, 1,-1, 0,-1};  //coeffs1 byte 3
    alt_8   C_0_m1[7]   = {1, 1, 2,-2,-1,-1,-2};  //coeffs1 byte 2
    alt_8   C_0_0[7]    = {2, 8, 4, 5, 9, 5, 28}; //coeffs1 byte 1
    alt_8   C_0_p1[7]   = {1, 1, 2,-2,-1,-1,-2};  //coeffs1 byte 0
    alt_8   C_p1_m1[7]  = {2, 1, 2, 1,-1, 0,-1};  //coeffs2 byte 3
    alt_8   C_p1_0[7]   = {2, 1, 1,-2,-1,-1,-2};  //coeffs2 byte 2
    alt_8   C_p1_p1[7]  = {2, 1, 1, 1,-1, 0,-1};  //coeffs2 byte 1
    alt_8   scale[7]    = {16,16,16,1, 1, 1, 16}; //coeffs2 byte 0

    alt_u32 coeffs0=0x0000, coeffs1=0x0000, coeffs2=0x0000;


-------------------------------------------------------------------------------------


            // when push button 3 pressed
            case 3 :

            	coeffs0=0x0000; //reset all coefficients to zero
            	coeffs1=0x0000;
            	coeffs2=0x0000;


            	//we use three 32-bit variables here
            	//we have 8*10 = 80 bits of coefficient data we need to transfer
            	//we use all 32 bits of coeffs1 and coeffs2
            	//we only need 16 bits of coeffs0

            	//all of this shifting and ORing below fills the coeffs variables with the coefficient
            	//data we've set above.

                coeffs0 = C_m1_m1[coeff_id] & 0xFF;           //coeffs0 contains 2 8-bit values
                coeffs0 <<= 8;
                coeffs0 = coeffs0 | (C_m1_0[coeff_id] & 0xFF);

                coeffs1 = C_m1_p1[coeff_id] & 0xFF;		       //coeffs1 contains 4 8-bit values
                coeffs1 <<= 8;
                coeffs1 = coeffs1 | (C_0_m1[coeff_id] & 0xFF);
                coeffs1 <<= 8;
                coeffs1 = coeffs1 | (C_0_0[coeff_id] & 0xFF);
                coeffs1 <<= 8;
                coeffs1 = coeffs1 | (C_0_p1[coeff_id] & 0xFF);

                coeffs2 = C_p1_m1[coeff_id] & 0xFF;		           //coeffs2 contains 4 8-bit values
                coeffs2 <<= 8;
                coeffs2 = coeffs1 | (C_p1_0[coeff_id] & 0xFF);
                coeffs2 <<= 8;
                coeffs2 = coeffs1 | (C_p1_p1[coeff_id] & 0xFF);
                coeffs2 <<= 8;
                coeffs2 = coeffs1 | (scale[coeff_id] & 0xFF);

                printf("ID: %d\nCoeffs0: %.8X \nCoeffs1: %.8X \nCoeffs1: %.8X\n\n",coeff_id,coeffs0, coeffs1, coeffs2);

                IOWR(NIOS_LCD_CAMERA_COMPONENT_0_IMAGELINE_BASE, 4, 5);         //filter_config=5 for the verilog files

                //write the coefficients to the new registers we've created

                IOWR(NIOS_LCD_CAMERA_COMPONENT_0_IMAGELINE_BASE, 5, coeffs0);
                IOWR(NIOS_LCD_CAMERA_COMPONENT_0_IMAGELINE_BASE, 6, coeffs1);
                IOWR(NIOS_LCD_CAMERA_COMPONENT_0_IMAGELINE_BASE, 7, coeffs2);

                coeff_id ++; //increment the coeff_id, so the next time you press key 3, it uses the next set of coefficients


                if(coeff_id==7)coeff_id=0;