# US 10,536,608 B1 · Dithering in sRGB space > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,536,608 B1 - Document ID: US10536608B1 - Status: Granted - Kind: B1 - Application number: 16/051,313 - Filed: 2018-07-31 - Granted: 2020-01-14 - Earliest claimed: 2018-07-31 - Assignees: Facebook Technologies, LLC - Applicants: Oculus VR, LLC - Inventors: Edward Buckley; Larry Seiler - Web page: https://patentgrep.com/patent/US10536608B1 ## CPC - H04N 1/4051: {producing a dispersed dots halftone pattern, the dots having substantially the same size (different sizes H04N1/4057)} - H04N 1/4057: {the pattern being a mixture of differently sized sub-patterns, e.g. spots having only a few different diameters (multi-toning H04N1/40087)} - H04N 1/40012: {Conversion of colour to monochrome} - H04N 1/40081: {Soft dot halftoning, i.e. producing halftone dots with gradual edges} - H04N 1/40087: {Multi-toning, i.e. converting a continuous-tone signal for reproduction with more than two discrete brightnesses or optical densities, e.g. dots of grey and black inks on white paper} - H04N 1/6008: {with primary colour signals, e.g. RGB or CMY(K)} - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract The disclosed computer-implemented method for performing dithering in non-linear space may include receiving, as an input, a non-linear sRGB-encoded data stream that includes pixel data that is to be displayed on a display screen. The disclosed method may next include generating a dithering mask for the non-linear sRGB-encoded data stream. Still further, the method may include dithering the non-linear sRGB-encoded data stream using the generated dithering mask according to a scalar dithering algorithm or a vector dithering algorithm. The method may also include linearizing the dithered non-linear sRGB-encoded data stream for display on the display screen, and may include providing the linearized RGB-encoded data stream to the display screen for display. Various other methods, systems, and computer-readable media are also disclosed. ## Claims ### Claim 1 A computer-implemented method comprising: receiving, as an input, a non-linear sRGB-encoded data stream that includes pixel data that is to be displayed on a display screen; generating a dithering mask for at least one of the non-linear sRGB-encoded data stream or a linear-encoded data stream; dithering the non-linear sRGB-encoded data stream using the generated dithering mask according to at least one of a scalar dithering algorithm or a vector dithering algorithm; linearizing the dithered non-linear sRGB-encoded data stream for display on the display screen; and providing the linearized RGB-encoded data stream to the display screen for display. ### Claim 2 (depends on 1) The computer-implemented method of claim 1, wherein generating the dithering mask for the non-linear sRGB-encoded data stream comprises creating one or more noise patterns and comparing pixel values in the non-linear sRGB-encoded data stream to one or more noise values in the noise patterns, the comparison resulting in a dither value for each pixel. ### Claim 3 (depends on 2) The computer-implemented method of claim 2, wherein generating the dithering mask for the non-linear sRGB-encoded data stream comprises implementing a mask pattern with a specified density. ### Claim 4 (depends on 1) The computer-implemented method of claim 1, wherein dithering the non-linear sRGB-encoded data stream using the generated dithering mask is performed using a scalar dithering algorithm, and wherein input values for the dither mask are provided such that a specified input value results in an expected optical density. ### Claim 5 (depends on 4) The computer-implemented method of claim 4, wherein the expected optical density comprises a specified value between 0 and 1, and wherein different values are identified for non-linear sRGB-encoded data to reach the specified optical density. ### Claim 6 (depends on 1) The computer-implemented method of claim 1, further comprising linearizing the non-linear sRGB-encoded data stream into a linear RGB-encoded data stream, the linearizing being performed using a piecewise linearizing function, wherein dithering the non-linear sRGB-encoded data stream using the generated dithering mask is performed using a vector dithering algorithm, wherein the dithering mask is generated using the linear-encoded data stream, and wherein the generated dithering mask is used to identify a color's position in a unit cube, the color position defining a tetrahedral which defines a dither pattern. ### Claim 7 (depends on 1) The computer-implemented method of claim 1, wherein dithering the non-linear sRGB-encoded data stream using the generated dithering mask includes the following: linearizing the non-linear sRGB-encoded data stream into a linear RGB-encoded data stream, the linearizing being performed using a piecewise linearizing function; determining, for each pixel, which tetrahedral encloses the pixel, the tetrahedral defining a dither pattern; dithering the linear RGB-encoded data steam using the defined dither pattern; non-linearly quantizing the linear RGB-encoded data stream into non-linear sRGB-encoded format; and scaling the dithered non-linear sRGB-encoded data steam according to a specified scaling factor. ### Claim 8 (depends on 7) The computer-implemented method of claim 7, wherein the piecewise linearizing function approximates one or more linear segments which are combined using a specified function, the combination of linear segments resulting in the linear RGB-encoded data stream. ### Claim 9 (depends on 1) The computer-implemented method of claim 1, wherein dithering the non-linear sRGB-encoded data stream using the generated dithering mask includes the following: linearizing the non-linear sRGB-encoded data stream into a linear RGB-encoded data stream, the linearizing being performed using a piecewise linearizing function; determining, for each pixel, which tetrahedral encloses the pixel, the tetrahedral defining a dither pattern; dithering the non-linear sRGB-encoded data steam using the defined dither pattern; linearly quantizing the linear RGB-encoded data stream into linear sRGB-encoded format using a lookup table; and scaling the dithered non-linear sRGB-encoded data steam according to a specified scaling factor. ### Claim 10 (depends on 1) The computer-implemented method of claim 1, wherein linearly quantizing the linear RGB-encoded data stream into non-linear sRGB-encoded format using a lookup table is performed on a programmable hardware microprocessor. ### Claim 11 A system comprising: a display screen; a receiving module that receives, as an input, a non-linear sRGB-encoded data stream that includes pixel data that is to be displayed on the display screen; a mask generating module that generates a dithering mask for at least one of the non-linear sRGB-encoded data stream or a linear-encoded data stream; a dithering module that dithers the non-linear sRGB-encoded data stream using the generated dithering mask according to at least one of a scalar dithering algorithm or a vector dithering algorithm; a linearizing module that linearizes the dithered non-linear sRGB-encoded data stream for display on the display screen; and a data transmission module that sends the linearized RGB-encoded data stream to the display screen for display. ### Claim 12 (depends on 11) The system of claim 11, wherein dithering the non-linear sRGB-encoded data stream using the generated dithering mask includes the following: linearizing the non-linear sRGB-encoded data stream into a linear RGB-encoded data stream, the linearizing being performed using a piecewise linearizing function; determining, for each pixel, which tetrahedral encloses the pixel, the tetrahedral defining a dither pattern; dithering the linear RGB-encoded data steam using the defined dither pattern; non-linearly quantizing the linear RGB-encoded data stream into non-linear sRGB-encoded format; and scaling the dithered non-linear sRGB-encoded data steam according to a specified scaling factor. ### Claim 13 (depends on 12) The system of claim 12, wherein non-linearly quantizing provides non-linear sRGB-encoded pixel values along a specified sRGB curve. ### Claim 14 (depends on 13) The system of claim 13, wherein bit depth for the linearized RGB-encoded data stream is reduced without reducing image quality. ### Claim 15 (depends on 13) The system of claim 13, wherein dithering the non-linear sRGB-encoded data stream adds two mathematical operations over dithering linear RGB-encoded data. ### Claim 16 (depends on 12) The system of claim 12, wherein dithering the non-linear sRGB-encoded data stream using the generated dithering mask includes the following: linearizing the non-linear sRGB-encoded data stream into a linear RGB-encoded data stream, the linearizing being performed using a piecewise linearizing function; determining, for each pixel, which tetrahedral encloses the pixel, the tetrahedral defining a dither pattern; dithering the linear RGB-encoded data steam using the defined dither pattern; linearly quantizing the linear RGB-encoded data stream into non-linear sRGB-encoded format using a lookup table; and scaling the dithered non-linear sRGB-encoded data steam according to a specified scaling factor. ### Claim 17 (depends on 16) The system of claim 16, wherein the piecewise linearizing function approximates one or more linear segments which are combined using a specified function, the combination of linear segments resulting in the linear RGB-encoded data stream. ### Claim 18 (depends on 12) The system of claim 12, wherein generating the dithering mask for the non-linear sRGB-encoded data stream comprises creating one or more noise patterns and comparing pixel values in the non-linear sRGB-encoded data stream to one or more noise values in the noise patterns, the comparison resulting in a dither value for each pixel. ### Claim 19 (depends on 18) The system of claim 18, wherein generating the dithering mask for the non-linear sRGB-encoded data stream comprises implementing a mask pattern with a specified density. ### Claim 20 A computer-readable medium comprising: computer-readable instructions that, when executed by at least one processor of a computing device, cause the computing device to: receive, as an input, a non-linear sRGB-encoded data stream that includes pixel data that is to be displayed on a display screen; generate a dithering mask for at least one of the non-linear sRGB-encoded data stream or a linear-encoded data stream; dither the non-linear sRGB-encoded data stream using the generated dithering mask according to at least one of a scalar dithering algorithm or a vector dithering algorithm; linearize the dithered non-linear sRGB-encoded data stream for display on the display screen; and send the linearized RGB-encoded data stream to the display screen for display.