Image generating method and image generating apparatus

A camera comprising:

• a light source configured to emit an infrared (IR) signal;
• a receiver configured to receive the IR signal that is reflected from an object;
• and
• a processor configured to generate an IR image based on the reflected IR signal, determine whether the IR image is saturated based on comparison between at least one pixel value of the IR image and a reference pixel value, and control an intensity of the IR signal emitted by the light source based on a result of the determination,
• wherein the light source is further configured to emit plurality of IR signals having different phases, the plurality of IR signals being reflected from the object, and
• the processor is further configured to determine whether the IR image is saturated based on at least one of the reflected plurality of IR signals.