An image processing system for predicting ovulation using a test channel for collecting saliva sample and a miniature camera for capturing the image of the saliva at dried state for analyzing the crystalline patterns for ovulation prediction. A rotary bristle element is attached to the drive head and a notch-like test channel traverses the width of the drive head. A conductivity sensor is mounted on a wall of the test channel for detecting filling and drying of the saliva sample. An algorithm in the microprocessor analyzes the image of the dried saliva and calculates the characteristic line length of line segments of connected saliva dots. A ferning index is also defined and calculated based on the percentage of area coverage of line segments which are exceeding the threshold line length. Trend curves are established based on the daily saliva analysis in a woman's menstrual cycle for predicting days from the ovulation.