The contourlet coefficients corresponding to an image have strong correlations both at the same scale and between neighboring scales. Therefore, an adaptive threshold is firstly constructed by the intra-scale correlation property of contourlet coefficients. After the adaptive thresholding denoising, the inter-scale correlation of the contourlet coefficients is utilized to decide what processed coefficients to use. Based on the two above correlation properties of contourlet coefficients, a new adaptive conto...