This article introduces a novel method for encoding polarization information using metasurfaces based on a generalized form of Malus' law (GML), which allows for universal 2D projections between arbitrary elliptical polarization pairs across the entire Poincaré sphere (PS). The approach enables versatile polarization image transformation functions, including histogram stretching, thresholding, and image encryption within non-orthogonal PS loci. The GML provides an infinite degeneracy in polarization projection, offering new degrees of freedom for arbitrary modulation mappings and parallel information channels. The modulation trajectory on the PS can be engineered using arbitrary analytic functions or aligned grids. The GML-based metasurfaces can be used to encode polarization information in a pixelated level by treating each unit cell as a local waveplate or polarizer. This method significantly expands the encoding dimensionality of polarization information, enabling new opportunities for metasurfaces in polarization optics for both quantum and classical regimes. The study demonstrates the feasibility of this approach through experimental results, including histogram stretching, thresholding, and dual information channel encoding for arbitrary non-orthogonal polarizations. The results show that the GML-based metasurfaces can achieve enhanced polarization manipulation functionalities, providing unprecedented opportunities for optical analog image transformation. The method is applicable to various platforms, including conventional liquid crystal displays and birefringent 2D materials, enabling new classical and quantum information encoding methodologies. The study also highlights the potential of this approach for practical applications such as optical recording and cryptography.This article introduces a novel method for encoding polarization information using metasurfaces based on a generalized form of Malus' law (GML), which allows for universal 2D projections between arbitrary elliptical polarization pairs across the entire Poincaré sphere (PS). The approach enables versatile polarization image transformation functions, including histogram stretching, thresholding, and image encryption within non-orthogonal PS loci. The GML provides an infinite degeneracy in polarization projection, offering new degrees of freedom for arbitrary modulation mappings and parallel information channels. The modulation trajectory on the PS can be engineered using arbitrary analytic functions or aligned grids. The GML-based metasurfaces can be used to encode polarization information in a pixelated level by treating each unit cell as a local waveplate or polarizer. This method significantly expands the encoding dimensionality of polarization information, enabling new opportunities for metasurfaces in polarization optics for both quantum and classical regimes. The study demonstrates the feasibility of this approach through experimental results, including histogram stretching, thresholding, and dual information channel encoding for arbitrary non-orthogonal polarizations. The results show that the GML-based metasurfaces can achieve enhanced polarization manipulation functionalities, providing unprecedented opportunities for optical analog image transformation. The method is applicable to various platforms, including conventional liquid crystal displays and birefringent 2D materials, enabling new classical and quantum information encoding methodologies. The study also highlights the potential of this approach for practical applications such as optical recording and cryptography.