This document presents a method for image segmentation using modified bacterial foraging optimization and RGB decomposition. The image is decomposed into R, G, and B color planes. Thresholds are calculated for each plane using the modified bacterial foraging algorithm. A final threshold is calculated as the average of the three thresholds and applied to the original image for segmentation. Performance is measured using metrics like PSNR, standard deviation, entropy, and class variance. The method is tested on several images and results show improved thresholds compared to other methods like Otsu thresholding. While computation time increases with image size, the segmentation accuracy is better than other thresholding techniques.