relate image pixel intensity with each row of table

I have a table of 256x482x2 and I have converted image intensity values to 1D array. Now I want to relate each pixel value to each row of table which includes elliptic curve pointsso we get point for each pixel vaue and for repeating pixel value we move to next column of same row. I need help with code.

disp('y^2 = x^3 + 5376x + 2438 mod 123457')
a=0:123456;
left_side = mod(a.^2,123457);
right_side = mod(a.^3+5376*a+2438,123457);
points = [];
for i = 1:length(right_side)
I = find(left_side == right_side(i));
for j=1:length(I)
    points = [points;a(i),a(I(j))];
end
end
plot(points(:,1),points(:,2),'ro')
set(gca,'XTick',0:1:123456)
set(gca,'YTick',0:1:123456)
grid on;
pad_needed = 256 - (mod(size(points,1) - 1, 256) + 1);
if pad_needed > 0
points(end+pad_needed,:) = 0;
end
T = points;
Z = reshape(T,256,482,2);
img=rgb2gray(imread('lena.jpg'));
V=img(:);
V=V';