4. An information processing apparatus according to claim 1 , wherein the at least one processor is further configured to: output success/failure information showing whether extraction of token points that conform to the extraction criterion succeeded, and adjust a value of a gradient of the criterion line based on the success/failure information.
4. An information processing apparatus according to claim 1 , wherein the at least one processor is further configured to: output success/failure information showing whether extraction of token points that conform to the extraction criterion succeeded, and adjust a value of a gradient of the criterion line based on the success/failure information. 6. An information processing apparatus according to claim 4 , wherein the at least one processor is further configured to adjust the value of the gradient of the criterion line by one of adding a specified adjustment value to and subtracting a specified adjustment value from the value of the gradient of the criterion line.