Spectral reconstruction is an important way to acquire a high-spatial-resolution multispectral image, and the spectral reconstruction algorithm is the key to its implementation. This work conducts a comparative study of spectral reconstruction algorithms under different asymmetric influencing factors to provide an overview of their performance. Seventeen spectral reconstruction algorithms with different mathematical bases were implemented and compared regarding their adaptability to response format, imaging noise, spectra type, exposure change, and the quality of the reconstructed images. Based on the principles and characteristics of the algorithm, qualitative and quantitative statistical analyses of the results were carried out. Results show that most of the current algorithms: (1) are adaptive to raw and image signal processing (ISP) responses for spectral reconstruction, (2) decrease their spectral reconstruction accuracy with an increase in imaging noise, (3) give poor performance in reconstructing smooth spectra using non-smooth spectra, and (4) exhibit different degrees of sensitivity to exposure changes. In addition, the image quality reconstructed using the raw response is superior to the ISP response.

To overcome the complexity of yarn color measurement using spectrophotometry with yarn winding techniques and to enhance consistency with human visual perception, a yarn color measurement method based on digital photography is proposed. This study employs a photographic colorimetry system to capture digital images of single yarns. The yarn and background are segmented using the K-means clustering algorithm, and the centerline of the yarn is extracted using a skeletonization algorithm. Spectral reconstruction and colorimetric principles are then applied to calculate the color values of pixels along the centerline. Considering the nonlinear characteristics of human brightness perception, the final yarn color is obtained through a nonlinear texture-adaptive weighted computation. The method is validated through psychophysical experiments using six yarns of different colors and compared with spectrophotometry and five other photographic measurement methods. Results indicate that among the seven yarn color measurement methods, including spectrophotometry, the proposed method—based on centerline extraction and nonlinear texture-adaptive weighting—yields results that more closely align with actual visual perception. Furthermore, among the six photographic measurement methods, the proposed method produces most similar to those obtained using spectrophotometry. This study demonstrates the inconsistency between spectrophotometric measurements and human visual perception of yarn color and provides methodological support for developing visually consistent color measurement methods for textured textiles.