1. A method for generating a target perspective model referenced for depth map generation, comprising: receiving a first input image; utilizing a region-based analysis circuit for analyzing a plurality of regions in the first input image to extract image characteristics of the regions; and determining the target perspective model of the first input image according to at least the image characteristics, comprising: selecting a specific region with a specific image characteristic from the regions of the first input image; referring to at least the selected specific region to determine a first perspective model; and when temporal smoothing is performed, generating the target perspective model by a weighted sum of the first perspective model and at least one second perspective model, wherein the target perspective model is not a depth map of the first input image, and the depth map, the target perspective model and the image characteristics are generated for a same single image.