In this paper, we will discuss the Quality of Edge Detected at different threshold values. For the purpose we will compare among Bacterial Foraging Algorithm, Canny Edge detector and Sobel Edge Detector. The Algorithm Bacterial Foraging also uses a thickness constraint and follows the Swarm intelligence feature and works like the behavior of bacteria in the search of food, Whereas Canny uses eliminates noise then apply Gaussian Filter and Sobel uses the concept of Image Gradient for Edge detection. In this paper we will observe a common image with different thresholds with different techniques. In the end we will find the optimal values of threshold for each techniques.