Edge Count Heuristic

Implement a simple edge detection technique to count the number of edges in a grayscale image. This task involves applying a basic heuristic to identify pixels with significant intensity changes.

The concept of edge detection is crucial in computer vision as it helps in identifying boundaries and structures within an image. A grayscale image can be represented as a 2D array of intensity values, where each pixel's value is a scalar between 0 and 255. The absolute difference between neighboring pixels can be used to determine the presence of an edge.

To detect edges, follow these steps:

1. Iterate over each pixel in the image, excluding border pixels.
2. For each pixel, calculate the absolute difference with its 4-neighbors.
3. If any of these differences exceed a given threshold, mark the pixel as an edge.

This technique is widely used in image processing applications.