Apparatus and method for generating depth image

An apparatus for generating a depth image, the apparatus comprising:

• an optical modulator which optically modulates reflective light which is reflected light from an object to which light modulated using N first pseudorandom (PN) sequences having, respectively, N different time shifts is irradiated, by use of a second PN-sequence which has a same PN sequence as that of the first PN-sequences but has a time shift different from those of the first PN-sequences;
• an optical sensor which senses the optically modulated reflective light;
• and
• a depth image process unit which samples N intensity images from light signals sensed by the optical sensor and generates a depth image of the object using the sampled N intensity images,
• wherein the depth image process unit individually determines respective depth extraction errors of each of a plurality of depths when the plurality of depths are determined according to a plurality of times of flight of light that are predicted using the N sampled intensity images, and selects a depth of the plurality of depths having a smallest error deviation estimate of the errors as a final depth of the depth image,
• wherein the depth image process unit calculates a time of flight of light that is irradiated from a light source and reaches the optical sensor based on the N sampled intensity images, and
• wherein when N is a number that is equal to or greater than 3, the depth image process unit determines whether an intensity image IM havin a minimum intensity among the three or more sampled intensity images is a first captured intensity image I1 or a thirdly captured intensity image I3, and calculates a depth according to the determination result.

A method of generating a depth image, the method comprising:

• performing optical modulation on reflective light which is reflected light from an object to which light modulated using a first pseudorandom (PN) sequence is irradiated, by use of a second PN-sequence which has a same PN sequence as a first PN-sequence but the second PN-sequence has N different time shifts;
• sensing the optically modulated reflective light using an optical sensor;
• sampling N intensity images obtained from the sensed optically modulated reflective light;
• and
• generating a depth image of the object using the N sampled intensity images,
• wherein the generating comprises individually determining respective depth extraction errors of each of a plurality of depths when the plurality of depths are determined according to a plurality of times of flight of light that are predicted using the N sampled intensity images, and selecting a depth of the plurality of depths having a smallest error deviation estimate of the errors as a final depth of the depth image, and
• wherein the method further comprises:
• calculating a time of flight of light that is irradiated from a light source and reaches the optical sensor based on the N sampled intensity images, and
• when N is a number that is equal to or greater than 3, determining whether an intensity inriageavin a minimum intensity among the three or more sampled intensity images is a first captured intensity image I1 or a thirdly captured intensity image I3, and calculating a depth according to the determination result.

A method of generating a depth image, the method comprising:

• irradiating light modulated using a first pseudorandom (PN) sequence toward an object;
• optically modulating, using a plurality of second PN-sequences, light that is reflected off of the object, the second PN-sequences having a same PN-sequence as the first PN sequence;
• sensing the optically modulated light using an optical sensor;
• sampling N intensity images from the sensed optically modulated light;
• and
• generating a depth image of the object using the N sampled intensity images,
• wherein the second PN-sequences have N different time shifts, and
• wherein the generating comprises individually determining respective depth extraction errors of each of a plurality of depths when the plurality of depths are determined according to a plurality of times of flight of light that are predicted using the N sampled intensity images, and selecting a depth of the plurality of depths having a smallest error deviation estimate of the errors as a final depth of the depth image, and
• wherein the method further comprises:
• calculating a time of flight of light that is irradiated from a light source and reaches the optical sensor based on the N sampled intensity images, and
• wherein when N is a number that is equal to or greater than 3, determining whether an intensity image IM having a minimum intensity among the three or more sampled intensity images is a first captured intensity image I1 or a thirdly captured intensity image I3, and calculating a depth according to the determination result.