Extension of DCT sign phase correlation to subpixel registration

We present a subpixel estimation technique for DCT sign phase correlation (DCT-SPC). The DCT-SPC requires only the signs of DCT coefficients and can be used in order to estimate the translation between signals. However, the translation values estimated by DCT-SPC were limited to integer numbers. The proposed technique enables DCT-SPC to estimate translation with subpixel accuracy. Considering the relation between DCT-SPC and phase-only correlation, we derive a subpixel estimation technique for DCT-SPC. Experimental results are shown to confirm the appropriateness and effectiveness of the proposed technique.