An image processing circuit for multi-illumination white balance with thumbnail processing. The image processing circuit determines a set of initial weights for a source pixel in a thumbnail image by determining component values for multiple color channels of the source pixel. The image processing circuit determines a set of weights for the source pixel in a weight map for the thumbnail image. Each weight in the set of weights is determined based on corresponding initial weights from the set of initial weights. Each weight in the set of weights represents an intensity level of a respective chrominance class of multiple chrominance classes for the source pixel. The image processing circuit applies the set of weights to values of the color channels of the source pixel to generate color component values of the color channels of a target pixel in a target thumbnail image.

A method performed by a server can include sending a first webpage to a first computing device, the first computing device including a camera, the first webpage including an image-capturing function and including an instruction for a user to obtain a second webpage via a second computing device, the second webpage including a calibration image file; receiving, from the first computing device, multiple captured images that were captured by the camera, the multiple calibration images including instances of a calibration image presented by a display included in the second computing device, the calibration image being a representation of the calibration image file; and based on the multiple captured images, calibrating the camera.

A method performed by a server can include sending a first webpage to a first computing device, the first computing device including a camera, the first webpage including an image-capturing function and including an instruction for a user to obtain a second webpage via a second computing device, the second webpage including a calibration image file; receiving, from the first computing device, multiple captured images that were captured by the camera, the multiple calibration images including instances of a calibration image presented by a display included in the second computing device, the calibration image being a representation of the calibration image file; and based on the multiple captured images, calibrating the camera.

A method for converting an initial datum between a colour space of a first colorimetric system and a colour space of a second colorimetric system, the initial datum being formed of at least one element expressed in a colorimetric reference system, the method includes: converting the initial datum into a projected datum, by expressing the at least one element in the colour space of the first colorimetric system; adapting the projected datum into an adapted datum, by expressing the at least one element in the colour space of the second colorimetric system. The colour space of the first colorimetric system and of the second colorimetric system are each a hyperbolic space defined by a hyperbolic metric projective reference system.

A method for converting an initial datum between a colour space of a first colorimetric system and a colour space of a second colorimetric system, the initial datum being formed of at least one element expressed in a colorimetric reference system, the method includes: converting the initial datum into a projected datum, by expressing the at least one element in the colour space of the first colorimetric system; adapting the projected datum into an adapted datum, by expressing the at least one element in the colour space of the second colorimetric system. The colour space of the first colorimetric system and of the second colorimetric system are each a hyperbolic space defined by a hyperbolic metric projective reference system.

A distributed image signal processing (ISP) system for a head-mounted device reduces the power load on the battery of the head-mounted device. The distributed ISP system includes a Bayer image processing engine, an RGB image processing engine, and a YUV image processing engine. The Bayer image processing engine is operated by, for example, processing logic of the head-mounted device. The Bayer image processing engine provides Bayer image data from raw image data. The YUV image processing engine is operated by, for example, processing logic of a (companion) computing device (e.g., a phone, tablet, laptop, compute puck, personal computer). The computing device is communicatively coupled (e.g., wired or wirelessly) to the head-mounted device to receive image data. The RGB image processing engine may be operated by the head-mounted device or the computing device.

Apparatuses, systems, and methods related to an image processor formed in an array of memory cells are described. An image processor as described herein is configured to reduce complexity and power consumption and/or increase data access bandwidth by performing image processing in the array of memory cells relative to image processing by a host processor external to the memory array. For instance, one apparatus described herein includes sensor circuitry configured to provide an input vector, as a plurality of bits that corresponds to a plurality of color components for an image pixel, and an image processor formed in an array of memory cells. The image processor is coupled to the sensor circuitry to receive the plurality of bits of the input vector. The image processor is configured to perform a color correction operation in the array by performing matrix multiplication on the input vector and a parameter matrix to determine an output vector that is color corrected.

A method for generating color conversion information including providing a user with color sample information for determining a color sample of which color characteristic information is known, receiving, from the user, an image including the color sample determined by the color sample information in a lighting environment, and generating color conversion information which corresponds to the lighting environment and is correlated with the user, based on the image and the color characteristic information of the color sample determined by the color sample information. The color conversion information converts between color information and color characteristic information, the color information is information which corresponds to a lighting environment and indicates colors of an object in the lighting environment, and the color characteristic information indicates color characteristics of the object.

A color calibration method includes acquiring first pictures in a first color space, a first picture being generated by one pure color; converting brightness of the first pictures from the first color space to a second color space to obtain second pictures in the second color space to display through a display device; acquiring photographed pictures by photographing the second pictures, the photographed pictures corresponding to a third color space; converting the photographed pictures from the third color space to the first color space to obtain photographed pictures in the first color space, and determining photographing color information corresponding to the photographed pictures in the first color space; and determining a difference between standard color information of the first color space and the photographing color information, and determining color calibration information according to the difference, the color calibration information being used for performing color calibration on a picture.

A color calibration method includes acquiring first pictures in a first color space, a first picture being generated by one pure color; converting brightness of the first pictures from the first color space to a second color space to obtain second pictures in the second color space to display through a display device; acquiring photographed pictures by photographing the second pictures, the photographed pictures corresponding to a third color space; converting the photographed pictures from the third color space to the first color space to obtain photographed pictures in the first color space, and determining photographing color information corresponding to the photographed pictures in the first color space; and determining a difference between standard color information of the first color space and the photographing color information, and determining color calibration information according to the difference, the color calibration information being used for performing color calibration on a picture.