Question: Please help me write a C# program to double or quadruple the size of an image using the SINC FUNCTION from the slides below .

Please help me write a C# program to double or quadruple the size of an image using the SINC FUNCTION from the slides below.

Please help me write a C# program to double or quadruple the

INTERPOLATION USING THE SINC FUNCTION An image with resolution NM pixels can be thought of as a group of M signals each one having period of (1/N). Thus to interpolate along a scan line we can use the Sinc function: N-1 sin(T(x-n)) f(x) = (x-n) n=0 sin(nt(x-n)) f(x) = EN=f(n) (x-n) Thus N-1 sin(T(K-n)) f(K) = TT (K-n) f(n) rn) n) 1. 2. n=0 N-1 f(x+2) = {f(n) sin(n(*+-n) f (K +) = f(0) K+1/2 n=0 TE ... (2k-3) sin" (2+1) sin (2k-1) sin" ( 2-3) f(1) + f(2) (2k+1) (2k-1) 2 311 25T sin sin sin f(k)+2+ f(k + 1) + f(k+2) 37+ f(k + 3) 57 + f(k + N-1 sin(TE f(n) (r(K +-n) f(x +) - 2 sin TE P=0 2 3. 4. The normalized coefficients are (-2/7na), (2/ 5a), (-2/3a), (2/ta), (2a).(-2/3na), (2/51a), (-2/7sta) where, In order to reduce the number of operations, if we need to double the resolution of the line, we can use 4 coefficients to the left and 4 to the right of the mid point to be interpolated. In order to do that the coefficients (- 2/71), (2/5), (-2/37), (2/7), (2/1), (-2/31), (2/5), (-2/77) must be normalized. a=4/(1-1/3 + 1/5 - 1/7) 5. 6. a = (4/) * (76/105) Thus, the normalized coefficients are, (-105 / 14 *76), (105 / 10 *76), (-105 / 6 *76), (105 / 2 *76), (105 / 2 *76), (-105 / 6*76), (105 / 10 *76), (-105 / 14 *76) So the coefficients are, -0.0986842, 0.138158,-0.230263, 0.690789, 0.690789,-0.230263, 7. 0.138158,-0.0986842 The coefficients are: -0.0986842, 0.138158,-0.230263, 0.690789, 0.690789,-0.230263, 0.138158,-0.0986842 And = -0.09868421k-3)+0.138158f{k-2)-0.230263f(k-1)+0.6907891(k)+0.690789f{k+1) 8.-0.230263f(k+2)+0.138158(k+3)-0.0986842f(k+4) For interpolating in the y-direction the same filter can be used for the vertical direction. For arbitrary x either the Sinc formula can be used directly or if we interested in fast execution a look up function can be used Interpolation is also called Supersampling. Subsampling by 2 can be attained by obtaining every other sample, or p. by interpolation using the existing samples. Floating point operations are computationally expensive, an integer approximation to the above formula is: f(K+/2=1/100 (-10f(k-3)+14f(k-2)-23f(k-1) +69f(k)+69f(k+1)-23f(k+2)+14f(k+3)- 10f(k+4)+50] 10. INTERPOLATION USING THE SINC FUNCTION An image with resolution NM pixels can be thought of as a group of M signals each one having period of (1/N). Thus to interpolate along a scan line we can use the Sinc function: N-1 sin(T(x-n)) f(x) = (x-n) n=0 sin(nt(x-n)) f(x) = EN=f(n) (x-n) Thus N-1 sin(T(K-n)) f(K) = TT (K-n) f(n) rn) n) 1. 2. n=0 N-1 f(x+2) = {f(n) sin(n(*+-n) f (K +) = f(0) K+1/2 n=0 TE ... (2k-3) sin" (2+1) sin (2k-1) sin" ( 2-3) f(1) + f(2) (2k+1) (2k-1) 2 311 25T sin sin sin f(k)+2+ f(k + 1) + f(k+2) 37+ f(k + 3) 57 + f(k + N-1 sin(TE f(n) (r(K +-n) f(x +) - 2 sin TE P=0 2 3. 4. The normalized coefficients are (-2/7na), (2/ 5a), (-2/3a), (2/ta), (2a).(-2/3na), (2/51a), (-2/7sta) where, In order to reduce the number of operations, if we need to double the resolution of the line, we can use 4 coefficients to the left and 4 to the right of the mid point to be interpolated. In order to do that the coefficients (- 2/71), (2/5), (-2/37), (2/7), (2/1), (-2/31), (2/5), (-2/77) must be normalized. a=4/(1-1/3 + 1/5 - 1/7) 5. 6. a = (4/) * (76/105) Thus, the normalized coefficients are, (-105 / 14 *76), (105 / 10 *76), (-105 / 6 *76), (105 / 2 *76), (105 / 2 *76), (-105 / 6*76), (105 / 10 *76), (-105 / 14 *76) So the coefficients are, -0.0986842, 0.138158,-0.230263, 0.690789, 0.690789,-0.230263, 7. 0.138158,-0.0986842 The coefficients are: -0.0986842, 0.138158,-0.230263, 0.690789, 0.690789,-0.230263, 0.138158,-0.0986842 And = -0.09868421k-3)+0.138158f{k-2)-0.230263f(k-1)+0.6907891(k)+0.690789f{k+1) 8.-0.230263f(k+2)+0.138158(k+3)-0.0986842f(k+4) For interpolating in the y-direction the same filter can be used for the vertical direction. For arbitrary x either the Sinc formula can be used directly or if we interested in fast execution a look up function can be used Interpolation is also called Supersampling. Subsampling by 2 can be attained by obtaining every other sample, or p. by interpolation using the existing samples. Floating point operations are computationally expensive, an integer approximation to the above formula is: f(K+/2=1/100 (-10f(k-3)+14f(k-2)-23f(k-1) +69f(k)+69f(k+1)-23f(k+2)+14f(k+3)- 10f(k+4)+50] 10

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