NEDI Edge Interpolation

In digital image processing, edge interpolation, bilinear interpolation, and weighted interpolation are commonly employed techniques. Specifically, when interpolating flat regions, bilinear interpolation serves as an appropriate method that calculates pixel values by averaging adjacent pixels in both horizontal and vertical directions. However, when dealing with edge regions requiring interpolation, weighted interpolation becomes necessary, where edge-aware weights are assigned based on local gradient magnitudes to preserve sharp transitions. To effectively distinguish between different region characteristics during the interpolation process, gradient information is typically utilized as a key metric - areas with low gradient values indicating flat regions while high gradient values signaling edge presence. The algorithm implementation typically involves computing gradient maps using operators like Sobel or Prewitt, then applying conditional interpolation: bilinear for low-gradient areas and edge-directed interpolation for high-gradient zones. These techniques play crucial roles in digital image processing by maintaining image quality during resizing or resolution enhancement operations.