Structured-light, triangulation-based three-dimensional digitizer

A system for determining a three dimensional profile of an object comprising:

• a first light-source unit for projecting a structured light pattern and a uniform illumination pattern for illumination of the object;
• a second light-source unit located symmetrically opposite to said first light-source unit and having a positional relationship with respect to said detector which mirrors the positional relationship between said first light-source unit and said detector;
• and
• an image-detecting device for detecting a sequence of images containing at least one of a structured light pattern image and a uniform illumination pattern image;
• wherein said structured light pattern comprises a plurality of light stripes each having a gradual variation in intensity of light, and wherein said image-capturing device is located relative to said first light-source unit at a known position, and wherein depth coordinates corresponding to two-dimensional coordinates of detected light stripes in each image are calculable by triangulation based on an angle of approach of each of said light stripes onto said object, whereby a plurality of three-dimensional coordinates representative of said three-dimensional profile of said object are determined,
• wherein said plurality of light stripes comprises light stripes of at least two different colors,
• wherein said structured light pattern and uniform illumination pattern are emitted from the same apparent optical source position, and
• wherein said first light-source unit and said second light-source unit each comprises two photographic flashes, and wherein said structured light pattern and said uniform illumination pattern are combined through a semitransparent mirror for each of said first light-source unit and said second light-source unit.

A system for determining a three dimensional profile of an object comprising:

• a first light-source unit for projecting a structured light pattern and a uniform illumination pattern for illumination of the object;
• a second light-source unit located symmetrically opposite to said first light-source unit and having a positional relationship with respect to said detector which mirrors the positional relationship between said first light-source unit and said detector;
• and
• an image-detecting device for detecting a sequence of images containing at least one of a structured light pattern image and a uniform illumination pattern image;
• wherein said structured light pattern comprises a plurality of light stripes each having a gradual variation in intensity of light, and wherein said image-capturing device is located relative to said first light-source unit at a known position, and wherein depth coordinates corresponding to two-dimensional coordinates of detected light stripes in each image are calculable by triangulation based on an angle of approach of each of said light stripes onto said object, whereby a plurality of three-dimensional coordinates representative of said three-dimensional profile of said object are determined,
• wherein said plurality of light stripes comprises light stripes of at least two different colors,
• wherein said structured light pattern and uniform illumination pattern are emitted from the same apparent optical source position, and
• wherein the image containing the structured light pattern is normalized by using the image containing uniform illumination pattern.

A system for determining a three dimensional profile of an object comprising:

• a first light-source unit for projecting a structured light pattern and a uniform illumination pattern for illumination of the object;
• and
• an image-detecting device for detecting a sequence of images containing at least one of a structured light pattern image and a uniform illumination pattern image;
• wherein said structured light pattern comprises a plurality of light stripes each having a gradual variation in intensity of light, and wherein said image-capturing device is located relative to said first light-source unit at a known position, and wherein depth coordinates corresponding to two-dimensional coordinates of detected light stripes in each image are calculable by triangulation based on an angle of approach of each of said light stripes onto said object, whereby a plurality of three-dimensional coordinates representative of said three-dimensional profile of said object are determined,
• wherein said plurality of light stripes comprises light stripes of at least two different colors, and
• wherein said first light-source unit comprises two photographic flashes, and wherein said structured light pattern and said uniform illumination pattern are combined through a semitransparent mirror.

A system for determining a three dimensional profile of an object comprising:

• a first light-source unit for projecting a structured light pattern and a uniform illumination pattern for illumination of the object;
• a second light-source unit located symmetrically opposite to said first light-source unit and having a positional relationship with respect to said detector which mirrors the positional relationship between said first light-source unit and said detector;
• and
• an image-detecting device for detecting a sequence of images containing at least one of a structured light pattern image and a uniform illumination pattern image;
• wherein depth coordinates corresponding to two-dimensional coordinates of detected light stripes in each image are calculable by triangulation based on an angle of approach of each of said light stripes onto said object, whereby a plurality of three-dimensional coordinates representative of said three-dimensional profile of said object are determined, and
• wherein said first light-source unit and said second light-source unit each comprises two photographic flashes, and wherein said structured light pattern and said uniform illumination pattern are combined through a semitransparent mirror for each of said first light-source unit and said second light-source unit.

A system for determining a three dimensional profile of an object comprising:

• a first light-source unit for projecting a structured light pattern and a uniform illumination pattern for illumination of the object;
• an image-detecting device for detecting a sequence of images containing at least one of a structured light pattern image and a uniform illumination pattern image;
• wherein said structured light pattern comprises a plurality of light stripes, and wherein depth coordinates corresponding to two-dimensional coordinates of detected light stripes in each image are calculable by triangulation based on an angle of approach of each of said light stripes onto said object, whereby a plurality of three-dimensional coordinates representative of said three-dimensional profile of said object are determined;
• wherein the image containing the structured light pattern is normalized by using the image containing uniform illumination pattern.

A system for determining a three dimensional profile of an object comprising:

• a first light-source unit for projecting a structured light pattern and a uniform illumination pattern for illumination of the object;
• and
• an image-detecting device for detecting a sequence of images containing at least one of a structured light pattern image and a uniform illumination pattern image;
• wherein said structured light pattern comprises a plurality of light stripes, and wherein depth coordinates corresponding to two-dimensional coordinates of detected light stripes in each image are calculable by triangulation based on an angle of approach of each of said light stripes onto said object, whereby a plurality of three-dimensional coordinates representative of said three-dimensional profile of said object are determined,
• wherein said first light-source unit comprises two photographic flashes, and wherein said structured light pattern and said uniform illumination pattern are combined through a semitransparent mirror.

A method for determining a three dimensional profile of an object, comprising:

• projecting a structured light pattern on an object, the structured light pattern including a plurality of stripes;
• capturing a structured light pattern image of the object;
• uniformly illuminating the object;
• capturing a uniform illumination image of the object;
• determining three-dimensional coordinates representative of the three-dimensional profile of the object as a function of the structured light pattern image;
• and
• determining a texture of the object as a function of at least the uniform illumination image.

A method for determining a three dimensional profile of an object using an image capturing device located at a known position relative to two light sources comprising:

• capturing a first image of the object while a structured light pattern including a plurality of light stripes is projected on the object from the first light source;
• capturing a second image of the object while a uniform illumination pattern is projected on the object from the first light source;
• capturing a third image of the object while a structured light pattern including a plurality of light stripes is projected on the object from the second light source;
• capturing a fourth image of the object while a uniform illumination pattern is projected on the object from the second light source;
• calculating, by triangulation based on an angle of approach of each of said light stripes, depth coordinates corresponding to two-dimensional coordinates of detected light stripes in the first and third captured images;
• and
• determining a plurality of three-dimensional coordinates representative of said three-dimensional profile of said object based on the two-dimensional coordinates of light stripes in the first and third captured images and corresponding calculated depth coordinates.