Abstract: A multi-primary conversion (5) of input drive values (RGB) defines a color of a pixel (PI) of a multi-primary display(DP) in an M dimensional color space (XYZ) into N>M output drive values (di) in an N dimensional drive space. The N output drive values (di) drive N sub-pixels (SPi) of the pixel (PI). The color of the pixel (PI) in the color space (XYZ) is defined by linear combinations of N color primaries of the respective N sub-pixels (SPi).

Abstract: A method of converting a three-primary input color signal (IS) comprising three input components (R, G, B) per input sample into an N-primary color drive signal (DS) comprising N?4 drive components (D1, . . . , DN) per output sample for driving N sub-pixels (SP1, . . . , SPN) of a color additive display. The N sub-pixels (SP1, . . . , SPN) have N primary colors. The method comprises adding (10), to three equations defining a relation between the N drive components (D1, . . . , DN) and the three input components (R, G, B), at least one linear equation defining a value for a combination of a first subset of the N drive components (D1, . . . , DN) and a second subset of the N-drive components (D1, . . . , DN) to obtain an extended set of equations. The first subset comprises a first linear combination (LC1) of 1?M1<N of the N drive components (D1, . . . , DN), and the second subset comprises a second linear combination (LC2) of 1?M2<N of the N drive components (D1, . . . , DN).

Abstract: A method for processing color image data that enables to optimally render a color image on a target device. The method incorporates a color gamut mapping step, where the amount of gamut mapping is adapted dynamically, in dependence of at least a color saturation value of the input pixel. Preferably, also a luminance value of the input pixel is used. The adaptive gamut mapping incorporates correction of saturation, and preferably also hue and white point, of the image data. The color gamut of the target device is used to the fullest possible extent, while clipping and loss of local details in highly saturated areas of the input image is largely prevented.

Abstract: A method of mapping a four primary input signal to sets of four sub-pixels of a display device, the method including sub-sampling the input samples of the four primary input signal by assigning the first, second and third input signals of a particular input sample to the first, second and third sub-pixels, producing first, second and third primary colors of a particular set of four adjacent sub-pixels, respectively, and the fourth input signal of a further input sample to the fourth sub-pixel, producing a fourth color of said particular set of the four adjacent sub-pixels, wherein the particular input sample and the further input sample are associated with adjacent positions on the display device.

Abstract: To have a good resolution/sharpness for the displayed pictures (e.g. low interference banding in case of showing a pattern having Nyquist limit problems), the multiprimary display (100), has more than 3 additive primaries (R,C,G,B), in which that half of the primaries (C,G) having the highest output luminances of the more than 3 additive primaries (R,C,G,B) when a corresponding driving signal (r) for the respective primary is maximal, is generatable by subpixels (104, 108) of the display at approximately equidistant subpixel positions (Dd).

Abstract: A driver (106) for driving pixels (104) of a display (102), wherein the pixels are divided into a first group and a second group and the driver is constructed for supplying a first drive signal to a first pixel and a second drive signal to a second pixel, the first and second pixels being neighboring pixels. The driver (106) comprises means for generating a first upper value and a first lower value; and means for generating a second upper value and a second lower value. It comprises means for driving, in a first operating mode, the first pixel with the first lower value and driving the second pixel with the second upper value. In a second operating mode, driving the first pixel with the first upper value and driving the second pixel with the second lower value. Means (108) for controlling the operating mode alternates between the first operating mode and the second operating mode.

Abstract: A method of gamut mapping maps an input image composed of pixels and having an input gamut (IG) defined by input RGB primaries (Ri, Gi, Bi) to a reproduction gamut (RG) defined by reproduction RGB primaries (Ro, Go, Bo). The reproduction gamut (RG) is narrower than the input gamut (IG). An input signal (RGBin) defined with respect to the input RGB primaries (Ri, Gi, Bi) is color transformed (1) into a transformed signal (RGBt) defined with respect to the reproduction RGB primaries (Ro, Go, Bo), whereby color information of the pixels (P1, P2, P3) within the reproduction gamut (RG) is preserved. Scaling factors (SFi) indicating a distance between on the one hand pixels (P1, P2, P3) of the transformed signal (RGBt) which are outside the reproduction gamut (RG), and on the other hand an edge of the reproduction gamut (RG) are determined (2).

Abstract: A color mapping method maps an input image signal (IS) into an output image signal (OS) for a display (DD) with display pixels (Pi) having sub-pixels (RP, GP, BP, YP) with primary colors (RW, GW, BW, YW) defining a display color gamut (WG). A look-up table (1) comprises stored luminances (LU) of reflective spectra (RS) at different chromaticities (?O) within the display color gamut (WG). The reflective spectra (RS) are spectra of reflective objects (RO) having a substantial maximum reflectivity at the corresponding chromaticities (?O). The color mapping method comprises a gamut mapping (2), retrieving (3) a looked-up luminance (Y1), a factor determination (4), and adapting the mapped luminance (Ym; Y). The gamut mapping (2) maps the input image signal (IS) having input pixel colors defined by an input luminance (Y) and an input chromaticity (x, y) into a mapped image signal (MS) having corresponding mapped pixel colors defined by a mapped luminance (Ym; Y) and a mapped chromaticity (xm, ym).

Abstract: An illuminating member (4) that, independent of any image content, comprises a central region (5) and an enclosing region (6), wherein said enclosing region (6) is adapted to emit light of lower quality than the light emitted by the central region (5). The illuminating member is adapted to illuminate a display panel (2) of a display device. By having the enclosing region emit light of lower brightness (dimming) a significant power reduction can be achieved for a wide range of typical images while largely maintaining the perceived image quality. Further, by using light emitting elements of lower quality for the enclosing region, manufacturing costs may be reduced while largely maintaining the perceived image quality.

Abstract: An improved subpixel arrangement for pixelated displays, wherein cross-shaped elements comprising a yellow subpixel surrounded by blue subpixels are distributed over the surface of the display. Further red and green subpixels can be arranged such that white light is emitted from three adjacent rows and three adjacent columns of a pixel comprising said cross-shaped element.

Abstract: To have an optimal use of a display for displaying particular, e.g.

Abstract: A method of displaying an image on a color display comprises receiving image data to be displayed, forming a first sub image and a second sub image from said image data, said first sub image comprising a first set of colors and said second sub image comprising a second set of colors, wherein said first set of colors and said second set of colors are disjoint sets, and wherein said first set of colors and said second set of colors comprise a metamer formed by at least a first color in said first set of colors and at least a second color in said second set of colors, and displaying said image using said first sub image and said second sub image, or a representation thereof, on a color display.

Abstract: The conversion unit (501) for processing an input video signal (Vin) to yield an output video signal (Vout) manifesting less color break-up when displayed on a temporal color display than the input video signal, the conversion unit comprises: an input (508) for a temporal color video signal;—a primary selection unit (511) arranged to obtain at least one picture-adaptive new color primary (IP) being determined striving for an optimization of a portion of a picture energy allocatable to the new color primary, in at least a picture region of the input video signal (Vin); and a color transformation unit (521) arranged to convert the input video signal to the output video signal represented in a color space comprising the at least one new color primary (IP), at least in the at least one picture region.

Abstract: The invention relates to a color display device for display a color image and a method of operating such display. The color display device is provided with a plurality of picture elements, two selectable light sources having different predetermined radiance spectra, color selection means which in combination with the selectable light sources is able to produce respective first and second primary colors on the display panel and control means arranged to select alternately one of the selectable light sources and to provide a portion of the picture elements with image information corresponding to the respective primary colors obtainable with the selected light source. The primary colors of the display device can be selected in a time sequential and space sequential way which enable a reduction of a color break-up.

Abstract: A method of redistributing an N-primary color input signal (IS) having a particular number?4 (N) of input components (I1, . . . , IN) into N-primary color output signal (OS) having the particular number (N) of output components (P1, . . . , PN) under a constraint (CON2). The method comprises defining (MPRC) three functions (F1, F2, F3) representing three (P1, P2, P3) of the output components (P1, . . . , PN) as a function of the remaining N-3 output components (P4, . . . , PN). Substituting (MPRC) the values of the input components (I1, . . . , IN) into the three functions (F1, F2, F3) to determine unknown coefficients (P1?, P2?, P3?) of the three functions (F1, F2, F3). And, determining (MPRC) optimal values of the output components (P1, . . . , PN) by applying the constraint (CON2) to the three functions (F1, F2, F3).

Abstract: A method of converting a three-primary input color signal (IS) comprising three input components (R, G, B) per input sample into an N-primary color drive signal (DS) comprising N?4 drive components (D1, . . . , DN) per output sample for driving N sub-pixels (SP1, . . . , SPN) of a color additive display. The N sub-pixels (SP1, . . . , SPN) have N primary colors. The method comprises adding (10), to three equations defining a relation between the N drive components (D1, . . . , DN) and the three input components (R, G, B), at least one linear equation defining a value for a combination of a first subset of the N drive components (D1, . . . , DN) and a second subset of the N-drive components (D1, . . . , DN) to obtain an extended set of equations. The first subset comprises a first linear combination (LC1) of 1?M1<N of the N drive components (D1, . . . , DN), and the second subset comprises a second linear combination (LC2) of 1?M2<N of the N drive components (D1, . . . , DN).

Abstract: A method of mapping a four primary input signal (IS) to sets (Pij) of four sub-pixels (RPij, GPij, BPij, WPij) of a display device (DD). The four primary input signal (IS) comprises a sequence of input samples (Sij) each comprising a value for a first input signal (Rlij), a value for a second input signal (Glij), a value for a third input signal (Blij), and a value for a fourth input signal (Wlij). The sets (Pij) of the four sub-pixels comprise a first sub-pixel (RPij) to supply light having a first primary color (R), a second sub-pixel (GPij) to supply light having a second primary color (G), a third sub-pixel (BPij) to supply light having a third primary color, and a fourth sub-pixel (WPij) to supply fourth light having a fourth color (W), the first, second, third and fourth color all being different, and the fourth color being within the color gamut of the first, second, and third color.

Abstract: The color gamut of a image display device is improved by the introduction of a broad band stop filter in combination with a band pass filter, a first light field and a second light field. The first light field is generated by a first and a second light source, emitting blue and green light, respectively. The second light field is generated by said second light source and a third light source emitting red light. The color gamut is improved since the band pass filter facilitates a displacement of the color point of said second light source towards shorter wavelengths, as the band pass filter transmits some of the blue light in the first light field. Similarly, a displacement towards longer wavelengths is facilitated, as the filter transmits some of the red light of said second light field. Hence, four primary colors are generated by only three light sources.