computer vision utilization for detection of green house tomato under natural illumination

agricultural sector experiences the application of automated systems since two decades ago. these systems are applied to harvest fruits in agriculture. computer vision is one of the technologies that are most widely used in food industries and agriculture. in this paper, an automated system based on computer vision for harvesting greenhouse tomatoes is presented. a ccd camera takes images from workspace and tomatoes with over 50 percent ripeness are detected through an image processing algorithm. in this research three color spaces including rgb, hsi and ycbcr and three algorithms including threshold recognition, curvature of the image and red/green ratio were used in order to identify the ripe tomatoes from background under natural illumination. the average error of threshold recognition, red/green ratio and curvature of the image algorithms were 11.82%, 10.03% and 7.95% in hsi, rgb and ycbcr color spaces, respectively. therefore, the ycbcr color space and curvature of the image algorithm were identified as the most suitable for recognizing fruits under natural illumination condition.