In a method to improve backwards compatibility when decoding high-dynamic range images coded in a wide color gamut (WCG) space which may not be compatible with legacy color spaces, hue and/or saturation values of images in an image database are computed for both a legacy color space (say, YCbCr-gamma) and a preferred WCG color space (say, IPT-PQ). Based on a cost function, a reshaped color space is computed so that the distance between the hue values in the legacy color space and rotated hue values in the preferred color space is minimized HDR images are coded in the reshaped color space. Legacy devices can still decode standard dynamic range images assuming they are coded in the legacy color space, while updated devices can use color reshaping information to decode HDR images in the preferred color space at full dynamic range.

Methods and systems are described for processing an image captured with an image sensor, such as a camera. In one embodiment, an estimated ambient light level of the captured image is determined and used to compute an optical-optical transfer function (OOTF) that is used to correct the image to preserve an apparent contrast of the image under the estimated ambient light level in a viewing environment. The estimated ambient light level is determined by scaling pixel values from the image sensor using a function that includes exposure parameters and a camera specific parameter derived from a camera calibration.

An object of the invention is to provide an image display system and the like useful for a remote diagnosis and treatment using color information such as a skin color and a tongue color of a patient. There is provided an image display system including: a color chart including a plurality of patches that include at least three patches selected from a group consisting of first to seventh patches having specific colors; an imaging device configured to simultaneously image the color chart and a person to be imaged and acquire image data; and a display device configured to receive the image data and display the image data as an image on a display unit.

In a method to improve backwards compatibility when decoding high-dynamic range images coded in a wide color gamut (WCG) space which may not be compatible with legacy color spaces, hue and/or saturation values of images in an image database are computed for both a legacy color space (say, YCbCr-gamma) and a preferred WCG color space (say, IPT-PQ). Based on a cost function, a reshaped color space is computed so that the distance between the hue values in the legacy color space and rotated hue values in the preferred color space is minimized HDR images are coded in the reshaped color space. Legacy devices can still decode standard dynamic range images assuming they are coded in the legacy color space, while updated devices can use color reshaping information to decode HDR images in the preferred color space at full dynamic range.

Example methods, apparatus, systems and articles of manufacture (e.g., physical storage media) to implement global tone mapping of images based on luminance and chrominance are disclosed. Examples disclosed herein determine a chromatic gain to apply to input chrominance components corresponding to an input color of a pixel of the input image, the chromatic gain based on an input luminance component corresponding to the input color of the pixel and a luminance gain to be applied to the input luminance component of the pixel to determine an output luminance component of the pixel. Disclosed examples also apply the chromatic gain to the input chrominance components of the pixel to determine output chrominance components of the pixel. Disclosed examples further combine the output luminance component and the output chrominance components to determine an output color of the pixel.

The present disclosure relates to an image processing apparatus. The image processing apparatus according to an embodiment of the present disclosure includes a display having a plurality of pixels, and a controller, wherein the controller: calculates an average luminance value of a first frame of an image based on RGB data corresponding to the image; sets a criterion for determining an output level of the plurality of pixels according to the average luminance value of the first frame; controls the display to output a first frame group, including the first frame, according to the set criterion; calculates an average luminance value of a second frame of the image according to a predetermined cycle; resets a criterion for determining the output level of the plurality of pixels according to the average luminance value of the second frame; and controls the display to output a second frame group, including the second frame, according to the reset criterion. Accordingly, by dynamically changing the criteria for determining the output level of the plurality of pixels included in the display based on the luminance value of each frame of the image, the image may be displayed more clearly. Various other embodiments are possible.

Systems and methods are disclosed for image signal processing. For example, methods may include accessing an image from an image sensor; detecting an object area on the image; classifying the object area on the image; applying a filter to an object area of the image to obtain a low-frequency component image and a high-frequency component image; determining a first enhanced image based on a weighted sum of the low-frequency component image and the high-frequency component image, where the high-frequency component image is weighted more than the low-frequency component image; determining a second enhanced image based on the first enhanced image and a tone mapping; and storing, displaying, or transmitting an output image based on the second enhanced image.

Video presence systems are described that detect an area of interest (e.g., facial region) within captured image data and analyze the area of interest using known color information of the content currently being presented by a display, along with measured ambient light color information from a color sensor, to determine whether the area of interest (e.g., face) is currently illuminated by the display or whether the AOI is not affected by the display and instead only illuminated by the ambient light. Upon determining that the display casts color shade on the AOI, the video presence system pre-processes the image data of the detected area of interest to correct the color back to skin color under ambient light prior to performing general white balance correction.

A system is provided for generating video content with hue-preservation in virtual production. The system comprises a memory for storing instructions and a processor configured to execute the instructions. Based on the executed instructions, the processor is further configured to control a saturation of scene linear data based on mapping of a first color gamut corresponding to a first encoding format of raw data to a second color gamut corresponding to a defined color space. The processor is further configured to determine a standard dynamic range (SDR) video content in the defined color space based on the scene linear data. Based on a scaling factor that is applied to three primary color values that describe the first color gamut, hue of the SDR video content is preserved.

Embodiments are directed towards hue-based video enhancement. An example method includes processing low dynamic range (LDR) video content to generate an inverse tone map (ITM) for transforming the LDR video content to high dynamic range (HDR) video content, converting the LDR video content into Hue, Saturation and Lightness (HSY) color space to produce H-channel data, S-channel data, and Y-channel data, de-noising the H-channel data, remapping the de-noised H-channel data, the S-channel data, and the Y-channel data based on the ITM; and rendering the HDR video content based thereon.