A projection device, including an illumination system, a control element, a driving element, a light valve, and a projection lens, is provided. The illumination system includes multiple light sources for providing multiple light beams to be combined into an illumination light beam. The driving element respectively drives the light sources in a first mode or a second mode, so that the light beams have respective luminous brightness, and the driving element is switched from the first mode to the second mode according to a first signal. The control element provides the first signal to the driving element according to an optical state or a time state of the projection device. The light valve is adapted to convert the illumination light beam into an image light beam. The projection lens is adapted to project the image light beam out of the projection device.

A projection device, including an illumination system, a control element, a driving element, a light valve, and a projection lens, is provided. The illumination system includes multiple light sources for providing multiple light beams to be combined into an illumination light beam. The driving element respectively drives the light sources in a first mode or a second mode, so that the light beams have respective luminous brightness, and the driving element is switched from the first mode to the second mode according to a first signal. The control element provides the first signal to the driving element according to an optical state or a time state of the projection device. The light valve is adapted to convert the illumination light beam into an image light beam. The projection lens is adapted to project the image light beam out of the projection device.

The present disclosure generally relates to a method and device of converting a high-dynamic-range (HDR) version of a picture to a standard-dynamic-range (SDR) version of this picture. The method is characterized in that it converts the high-dynamic-range version to the standard-dynamic-range version of the picture according to: a first indicator (I1) that indicates the presence of color mapping parameters; a second indicator (I2) that indicates whether a device is configured to convert the high-dynamic-range version to the standard-dynamic-range version of the picture by taking into account said color mapping parameters; and a third indicator (I3) that indicates whether converting without taking into account said color mapping parameters is inhibited.

The processing of RGB image data can be optimized by performing optimization operations on the image data when it is converted into the YCbCr color space. First, a raw RGB color space is converted into a YCbCr color space, and raw RGB image data is converted into YCbCr image data using the YCbCr color space. For each Y-layer of the YCbCr image data, a 2D LUT is generated. The YCbCr image data is converted into optimized CbCr image data using the 2D LUTs, and optimized YCbCr image data is generated by blending CbCr image data corresponding to multiple Y-layers. The optimized YCbCr image data is converted into sRGB image data, and a tone curve is applied to the sRGB image data to produce optimized sRGB image data.

For obtaining good quality luminance dynamic range conversion, we describe an image color processing apparatus (200) arranged to transform an input color (R,G,B) of a pixel of an input image (Im_R2) having a first luminance dynamic range into an output color (Rs, Gs, Bs) of a pixel of an output image (Im_res) having a second luminance dynamic range, which first and second dynamic ranges differ in extent by at least a multiplicative factor 1.5, comprising: a maximum calculation unit (201) arranged to calculate the maximum (M) of at least three components of the input color; a brightness mapper (202) arranged to apply a function (F) to the maximum, yielding an output value (F(M)), whereby the function is predetermined having a constraint that the output value for the highest value of the maximum (M) cannot be higher than 1.0; a scaling parameter calculator (203) arranged to calculate a scaling parameter (a) being equal to the output value F(M)) divided by the maximum (M); and a multiplier (204) arranged to multiply the three color components of the input color (R,G,B) by the scaling parameter (a), yielding the color components of the output color, wherein the color processing apparatus (200) comprises at least one component multiplier (303) arranged to multiply a component (B) of the input color with a weight (wB) being a real number yielding a scaled component (Bw) prior to input of that component in the maximum calculation unit (201).

For obtaining good quality luminance dynamic range conversion, we describe an image color processing apparatus (200) arranged to transform an input color (R,G,B) of a pixel of an input image (Im_R2) having a first luminance dynamic range into an output color (Rs, Gs, Bs) of a pixel of an output image (Im_res) having a second luminance dynamic range, which first and second dynamic ranges differ in extent by at least a multiplicative factor 1.5, comprising: a maximum calculation unit (201) arranged to calculate the maximum (M) of at least three components of the input color; a brightness mapper (202) arranged to apply a function (F) to the maximum, yielding an output value (F(M)), whereby the function is predetermined having a constraint that the output value for the highest value of the maximum (M) cannot be higher than 1.0; a scaling parameter calculator (203) arranged to calculate a scaling parameter (a) being equal to the output value F(M)) divided by the maximum (M); and a multiplier (204) arranged to multiply the three color components of the input color (R,G,B) by the scaling parameter (a), yielding the color components of the output color, wherein the color processing apparatus (200) comprises at least one component multiplier (303) arranged to multiply a component (B) of the input color with a weight (wB) being a real number yielding a scaled component (Bw) prior to input of that component in the maximum calculation unit (201).

An image processing apparatus is provided, that is configured to: extract a first pixel value corresponding to a first viewpoint that is one of a plurality of viewpoints to capture a subject image, at a target pixel position from image data having the first pixel value; extract second and third luminance values corresponding to second and third viewpoints that are different from the first viewpoint, at the target pixel position from luminance image data having the second and third luminance values; and calculate at least any of second and third pixel values of the second and third viewpoints such that a relational expression between the second or third pixel value and the first pixel value extracted by the pixel value extracting unit remains correlated with a relational expression defined by the second and third luminance values.

A method for wide dynamic range imaging is illustrated. A region mapping operation having steps as follows is applied to an image using a plurality of region mapping curves for compensating different luminance associated with a plurality of regions in the image. A low frequency image is obtained. A reference value for each region in the image is obtained according to the low frequency image. One region mapping curve is selected according to the reference value of the region. A gain curve is obtained according to the selected region mapping curve, a gain value of a pixel value or a luminance value of the region is obtained according to the gain curve, an adjusted gain value is obtained according to the luminance corresponding to the pixel value, and the pixel value is adjusted according to the luminance value, the gain value, and the adjusted gain value.

A method for wide dynamic range imaging is illustrated. A region mapping operation having steps as follows is applied to an image using a plurality of region mapping curves for compensating different luminance associated with a plurality of regions in the image. A low frequency image is obtained. A reference value for each region in the image is obtained according to the low frequency image. One region mapping curve is selected according to the reference value of the region. A gain curve is obtained according to the selected region mapping curve, a gain value of a pixel value or a luminance value of the region is obtained according to the gain curve, an adjusted gain value is obtained according to the luminance corresponding to the pixel value, and the pixel value is adjusted according to the luminance value, the gain value, and the adjusted gain value.

Provided is an image combination method that can represent the texture of a drawing medium such as paper without causing a foreground fading problem. The image combination method includes a step of acquiring an illumination-light component and a reflectance component from an input image, a step of generating a texture-combined image by combining the reflectance component or the corrected reflectance component and a texture image representing a desired texture, and a step of acquiring a combined image by combining the illumination-light component or the corrected illumination-light component and the texture-combined image.