1. A robot control apparatus that controls a robot having multiple joints, based on an image feature amount captured by a camera, the robot control apparatus comprising: an actuator configured to drive a joint shaft of the robot in each control cycle; a joint shaft angle sensor sensing a joint shaft angle of the joint shaft; an image capturing unit configured to obtain the image captured by the camera; an image feature amount calculating unit configured to calculate a first image feature amount representing a feature of an object, from the image captured by the camera; an image feature amount estimating unit configured to temporally interpolate the first image feature amount, and estimate a second image feature amount in each control cycle of the robot; an image Jacobian calculating unit configured to calculate an image Jacobian representing a ratio between a change in the second image feature amount and a change in the joint shaft angle; a target value input unit configured to set a target value in the image of the object; a target trajectory generating unit configure to generate a target trajectory in the image in each control cycle of the robot, using the target value and the second image feature amount; a joint shaft angle difference calculating unit configured to calculate a difference in the joint shaft angle, using the generated target trajectory and the image Jacobian; a torque command value calculating unit configured to determine a command value of the joint shaft angle based on the difference in the joint shaft angle, and calculate a torque command value of the joint shaft by using the command value of the joint shaft angle and the joint shaft angle sensed by the joint shaft angle sensor; a drive unit configured to drive the actuator, based on the torque command value; and a position and posture evaluating unit configured to calculate a correction amount for the target trajectory of the image feature amount from the joint shaft angle sensed by the joint shaft angle sensor, based on a hardware constraint on the robot, the correction amount for the target trajectory being used to perform feedback-control on the robot.