Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining a location relative to an object and a type of a light source that illuminated the object when the image was captured, are described. A method performed by a process executing on a computer system includes identifying an object of interest in a digital image. The method further includes projecting at least a portion of the digital image corresponding to the object of interest onto a three dimensional (3D) model that includes a polygon-mesh corresponding to the object's shape. The method further includes determining one or more properties of a light source that illuminated the object in the digital image at an instant that the image was captured based at least in part on a characteristic of one or more polygons in the 3D model onto which the digital image portion was projected.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, are disclosed for reducing the impact of lighting conditions and biometric distortions, while providing a low-computation solution for reasonably effective (low threshold) face recognition. In one aspect, the methods include processing a captured image of a face of a user seeking to access a resource by conforming a subset of the captured face image to a reference model. The reference model corresponds to a high information portion of human faces. The methods further include comparing the processed captured image to at least one target profile corresponding to a user associated with the resource, and selectively recognizing the user seeking access to the resource based on a result of said comparing.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining a location relative to an object and a type of a light source that illuminated the object when the image was captured, are described. A method performed by a process executing on a computer system includes identifying an object of interest in a digital image. The method further includes projecting at least a portion of the digital image corresponding to the object of interest onto a three dimensional (3D) model that includes a polygon-mesh corresponding to the object's shape. The method further includes determining one or more properties of a light source that illuminated the object in the digital image at an instant that the image was captured based at least in part on a characteristic of one or more polygons in the 3D model onto which the digital image portion was projected.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining a location relative to an object and a type of a light source that illuminated the object when the image was captured, are described. A method performed by a process executing on a computer system includes identifying an object of interest in a digital image. The method further includes projecting at least a portion of the digital image corresponding to the object of interest onto a three dimensional (3D) model that includes a polygon-mesh corresponding to the object's shape. The method further includes determining one or more properties of a light source that illuminated the object in the digital image at an instant that the image was captured based at least in part on a characteristic of one or more polygons in the 3D model onto which the digital image portion was projected.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, are disclosed relating to skin-tone filtering for reducing the impact of lighting conditions, while providing a low-computation solution for effective face detection. In one aspect, methods include sampling a digital image frame from among a series of digital image frames. The methods further include analyzing pixels within the sampled digital image frame to determine whether pixels in the sampled digital image frame have a hue, independent of lightness, that is within a range of hues corresponding to human skin tone. Further, the methods include deciding whether the sampled digital image frame includes a depiction of human skin based on a result of the analyzing.

Abstract: A method performed by a software process executing on a computer system includes selecting a first set of pixels in a digital image in the RGB color space. The pixels are selected such that, for each pixel in the set, a red component is a highest value component and a blue component is a lowest value component. The method also includes identifying at least a subset of the first set as a region of orange hue in the digital image.

Abstract: A method performed by a software process executing on a computer system, includes obtaining a digital image having a plurality of pixels encoded in a YUV color space. Each pixel has a luma component of value Y, a blue color-difference component of value U and a red color-difference component of value V. For a specified pixel, the method includes calculating whether U is less than a first threshold and V is greater than a second threshold. The method further includes determining whether the specified pixel potentially depicts an orange hue depending on a result of the calculation.

Abstract: A method performed by a software process executing on a computer system, includes obtaining a digital image having a plurality of pixels encoded in a YUV color space. Each pixel has a luma component of value Y, a blue color-difference component of value U and a red color-difference component of value V. For a specified pixel, the method includes calculating whether U is less than a first threshold and V is greater than a second threshold. The method further includes determining whether the specified pixel potentially depicts an orange hue depending on a result of the calculation.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, are described for rendering a mosaic from digital images using information about location and orientation of an image capturing device, and further about optics settings for the image capturing device when the digital images were captured. In one aspect, methods include generating respective virtual image sheets for frames captured from different camera locations and different camera orientations. Generating the virtual image sheets includes projecting texture maps of the captured frames over wire frames corresponding to optics settings of the camera. The methods further include positioning the generated virtual image sheets at locations and orientations within a viewing space that correspond to the different camera locations and the different orientations. The methods also include rendering the positioned virtual image sheets into a mosaic viewed from a reference point of the viewing space.

Abstract: A method, performed by a software process executing on a computer system, includes accessing a digital image comprising a plurality of pixels. The method also includes determining whether one or more pixels bounding a first rectangular sub-region of a predetermined size within the digital image satisfy a specified criterion. If a predetermined percentage of bounding pixels satisfy the specified criterion, the method assumes that all pixels within the first rectangular sub-region also satisfy the specified criterion. The method further includes selectively executing an image analysis algorithm on the digital image using the assumption that all pixels within the rectangular sub-region also satisfy the specified criterion.

Abstract: A method performed by a software process executing on a computer system includes selecting a first set of pixels in a digital image in the RGB color space. The pixels are selected such that, for each pixel in the set, a red component is a highest value component and a blue component is a lowest value component. The method also includes identifying at least a subset of the first set as a region of orange hue in the digital image.

Abstract: Methods, systems , and apparatus, including computer programs encoded on a computer storage medium, are disclosed for reducing the impact of lighting conditions and biometric distortions, while providing a low-computation solution for reasonably effective (low threshold) face recognition. In one aspect, the methods include processing a captured image of a face of a user seeking to access a resource by conforming a subset of the captured face image to a reference model. The reference model corresponds to a high information portion of human faces. The methods further include comparing the processed captured image to at least one target profile corresponding to a user associated with the resource, and selectively recognizing the user seeking access to the resource based on a result of said comparing.

Abstract: A method, performed by a software process executing on a computer system, includes accessing a digital image comprising a plurality of pixels. The method also includes determining whether one or more pixels bounding a first rectangular sub-region of a predetermined size within the digital image satisfy a specified criterion. If a predetermined percentage of bounding pixels satisfy the specified criterion, the method assumes that all pixels within the first rectangular sub-region also satisfy the specified criterion. The method further includes selectively executing an image analysis algorithm on the digital image using the assumption that all pixels within the rectangular sub-region also satisfy the specified criterion.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining a location relative to an object and a type of a light source that illuminated the object when the image was captured, are described. A method performed by a process executing on a computer system includes identifying an object of interest in a digital image. The method further includes projecting at least a portion of the digital image corresponding to the object of interest onto a three dimensional (3D) model that includes a polygon-mesh corresponding to the object's shape. The method further includes determining one or more properties of a light source that illuminated the object in the digital image at an instant that the image was captured based at least in part on a characteristic of one or more polygons in the 3D model onto which the digital image portion was projected.

Abstract: A method performed by a software process executing on a computer system, includes obtaining a digital image having a plurality of pixels encoded in a YUV color space. Each pixel has a luma component of value Y, a blue color-difference component of value U and a red color-difference component of value V. For a specified pixel, the method includes calculating whether U is less than a first threshold and V is greater than a second threshold. The method further includes determining whether the specified pixel potentially depicts an orange hue depending on a result of the calculation.

Abstract: A method performed by a software process executing on a computer system, includes accessing a digital image having a plurality of pixels encoded in a color space that defines hue as a pair of Cartesian coordinates. The method also includes calculating a chroma value for a specified pixel by determining a distance between a point corresponding to a hue coordinate pair value for the specified pixel and a Cartesian origin point. The calculated chroma value is compared to a predetermined threshold and an image processing operation is performed on the digital image based on a result of the comparison.

Abstract: A method, performed by a software process executing on a computer system, includes accessing a digital image comprising a plurality of pixels. The method also includes determining whether one or more pixels bounding a first rectangular sub-region of a predetermined size within the digital image satisfy a specified criterion. If a predetermined percentage of bounding pixels satisfy the specified criterion, the method assumes that all pixels within the first rectangular sub-region also satisfy the specified criterion. The method further includes selectively executing an image analysis algorithm on the digital image using the assumption that all pixels within the rectangular sub-region also satisfy the specified criterion.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, are described for immersive navigation and for rendering of dynamically reassembled panoramas, e.g., for rendering panoramas corresponding to user specified views of a scene depicted in a captured sequence of timed digital images. By dynamically altering reassembly of panoramic slices, a viewer can in effect navigate and pivot in and about a represented space, and can experience new viewing perspectives not apparent in individual panoramic frames.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, are described for rendering a mosaic from digital images using information about location and orientation of an image capturing device, and further about optics settings for the image capturing device when the digital images were captured. In one aspect, methods include generating respective virtual image sheets for frames captured from different camera locations and different camera orientations. Generating the virtual image sheets includes projecting texture maps of the captured frames over wire frames corresponding to optics settings of the camera. The methods further include positioning the generated virtual image sheets at locations and orientations within a viewing space that correspond to the different camera locations and the different orientations. The methods also include rendering the positioned virtual image sheets into a mosaic viewed from a reference point of the viewing space.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, are disclosed relating to skin-tone filtering for reducing the impact of lighting conditions, while providing a low-computation solution for effective face detection. In one aspect, methods include sampling a digital image frame from among a series of digital image frames. The methods further include analyzing pixels within the sampled digital image frame to determine whether pixels in the sampled digital image frame have a hue, independent of lightness, that is within a range of hues corresponding to human skin tone. Further, the methods include deciding whether the sampled digital image frame includes a depiction of human skin based on a result of the analyzing.