i = Import["http://i.stack.imgur.com/Ac8m0.png"];

img = Import["http://i.stack.imgur.com/Ac8m0.png"];

pts = Table[{x, y}, {x, 65, 598, 33}, {y, 64, 810, 24}];
key = Table[{697, y}, {y, 60, 810, 30}];

HighlightImage[img, {Flatten[pts, 1], ImageMarker[key, "Circle"]}]

keycols = ImageValue[img, key];

Row[RGBColor /@ keycols]

nf = Nearest[keycols -> Automatic];

data = Map[First[nf@ImageValue[img, #]] &, pts, {2}];

Graphics @ Raster[Map[keycols[[#]] &, Transpose[data], {2}]]