Abstract: A method, system, and computer-readable storage medium are disclosed for simulating brush behavior. In one embodiment, user input may be received to modify an image using a brush model, wherein the brush model comprises data stored in a memory of a computer system. The brush model may comprise a plurality of bristle representations. The user input may comprise a motion of the brush model. An effect of each of the plurality of bristle representations on the image throughout the motion may be determined. The image may be modified based on the determined effect of each of the plurality of bristle representations on the image throughout the motion.

Abstract: A method, system, and computer-readable storage medium for simulating bristle brush behavior in an image editing application may use stiffness-height parameterization to determine the height of a brush tool above a canvas during a brush stroke. The determination may be dependent on the pressure applied during the stroke (e.g., using a stylus on a pressure-sensitive tablet), and on the stiffness of the brush bristles. The system may select a standard-stiffness or high-stiffness mapping between stylus pressure values and brush height values dependent whether the bristle stiffness value is above or below a pre-determined threshold. The standard-stiffness mapping may apply a linear function to pressure values to determine height values. Using the high-stiffness mapping, the effect of increased pressure on corresponding brush height values may be reduced as bristle stiffness is increased.

Abstract: Systems and methods are provided for depth map estimation using normalized displacement of image pairs. In one embodiment, an image manipulation application identifies image pairs from an input image. Each of the image pairs includes an image portion from a first perspective and the image portion from a second perspective. The image manipulation generates displacement vectors for the image pairs. Each of the displacement vectors represents at least one of a horizontal displacement and a vertical displacement of the image portion from the first perspective to the second perspective. The image manipulation application generates normalized displacement vectors corresponding to the displacement vectors. Each of the normalized displacement vectors is generated by transforming a respective orientation of a corresponding one of the displacement vectors to a common reference direction. The image manipulation application generates a depth map based on the normalized displacement vectors.

Abstract: Systems and methods are provided for depth map estimation using three-dimensional epipolar data structures. The image manipulation application receives image data depicting an image space from a multiple perspectives. The image manipulation application generates at least one three-dimensional epipolar data structure from the image data. The at least one three-dimensional epipolar data structure includes data describing the difference in position of at least one object between the perspectives. The at least one three-dimensional epipolar data structure corresponds to at least one region of the image space. The image manipulation application generates a depth map based on the at least one three-dimensional epipolar data structure.

Abstract: Methods and apparatus for patch-based construction of an object shape from the shading of an image are disclosed. An image is divided into a set of image subregions. For each image subregion, a set of subregion dictionary entries is identified. Each of the set of subregion dictionary entries includes a subregion entry appearance matching an appearance of the respective image subregion and a subregion entry geometry. A set of optimal subregion dictionary entries is identified. Identifying the set of optimal subregion dictionary entries includes minimizing an energy function of the sets of subregion dictionary entries for all image subregions. Each optimal subregion dictionary entry is, for a respective one of the image subregions, a subregion entry associated with a minimum of the energy function. The shape includes a shape construction parameter from a subregion geometry entry of each optimal subregion geometry entry of the set of optimal subregion geometry entries.

Abstract: Systems, methods, and apparatus for simulating natural media painting in a digital painting application (or painting simulation module) may provide user interface elements and methods that allow a user to load a brush with non-uniform paint colors by directly sampling the digital canvas. For example, a user may hover the brush over an area on the canvas having a non-uniform color distribution, and the application (or module) may sample the colors of the pixels under the brush, and load the brush with a collection of paint values reflecting the non-uniform distribution of colors in the sample. The application may support two non-uniform paint loading modes, e.g., one that fills the brush with a distribution of paint matching a single sample, and one that fills the brush with paint continuously as it is swept over the canvas. Non-uniform paint loading may be applied to stamp-based brush models and/or bristle brush models.

Abstract: Methods and apparatus for construction of an object shape from an image using a light-space graphical model are disclosed. A set of normal vectors for a set of pixels in an image is defined. Each normal vector is defined in terms of an azimuth and a zenith measured in a spherical coordinate system centered on a light source illuminating the image. The zenith of each normal vector is constrained based on an observed shading of a respective pixel. A shape is constructed from the image. Constructing the shape includes minimizing an energy function to specify an azimuth value and a zenith value of each normal vector. Minimizing the energy function further includes constraining the azimuth of each normal vector based on an image gradient of the image at each respective pixel to enforce a coplanar assumption between the image gradient expressed in a three-dimensional space and the respective normal vector.

Abstract: A method, system, and computer-readable storage medium are disclosed for simulating bristle brush behavior and generating vector output from such simulations. User input may represent a stroke made by a paint brush comprising multiple bristles sweeping across a canvas. A vector representation of the brush stroke's effects may be generated by, for each of the plurality of bristles: determining a path along which the bristle has swept, and generating a vector representation of the path along which the bristle has swept (e.g., a set of Bézier curves, or straight line segments). The vector representation of the effects of the brush stroke may comprise the vector representations of the paths along which each of the plurality of bristles has swept. The vector representations of the paths of each bristle sweep may be composited over each other in an image editing application to depict the brush stroke for display and/or for printing.

Abstract: Systems, methods, and apparatus for simulating natural media painting in a digital painting application (or painting simulation module) may more accurately simulate real world painting techniques than conventional painting simulation applications. The digital painting application (or simulation module) may provide a small set of physically meaningful parameters (e.g., canvas wetness, drying rate, and pickup mix ratio). By setting the values of these parameters (or overriding default values for a selected paint type), the user may better control the appearance of brush strokes made by a virtual paint brush on a digital canvas. For example, the length of a brush stroke, the amount of streaking caused by paint picked up during the brush stroke, and/or the mix of paint deposited from a pickup buffer and a reservoir buffer of a brush model may be affected by changing the values of these parameters, thus allowing users to create different realistic painting effects.

Abstract: A curve editor may model a continuous curve as a finite collection of discrete mass points (among which the curve's mass is distributed) and associated springs. The springs may include damped axial springs between pairs of consecutive mass points, and damped bending springs representing interactions between sets of three consecutive mass points. In response to manipulation of the curve at various mass points, the curve editor may determine new positions and/or velocities of one or more mass points using a real time physical simulation of the spring forces acting at mass points involved in the editing operation. The simulation may be dependent on viscous drag forces and/or on constraints applied to individual mass points, angles defined by consecutive mass points, or an absolute direction of a segment between two mass points. Mass points may be added to or removed from the model by adaptive resampling, and the mass redistributed accordingly.

Abstract: Systems, methods, and apparatus for simulating natural media painting in a digital painting application (or painting simulation module) using a two-layer model of a virtual paint brush may more accurately simulate real world painting techniques than conventional painting simulations. A two-layer brush model may include a reservoir buffer and a pickup buffer to separately represent the paint stored in the belly of a paint brush tip and paint that has been picked up on the surface of the brush tip during a brush stoke, respectively. The two-layer brush model may also include methods that automatically control how virtual paint moves between these layers and a digital canvas. In simulations that employ this two-layer brush model, virtual paint may be deposited on the digital canvas directly from both of the buffers. The amount of paint deposited from each buffer (and/or the ratio of the amounts) may be configurable by a user.

Abstract: A method, system, and computer-readable storage medium are disclosed for determining characteristics of light sources. In one embodiment, an image comprising pixels may be received. The image may be affected by a plurality of light sources including a first light source and a second light source. The first light source and the second light source may overlap. The intensity and direction of each of the plurality of light sources in the image may be determined. In one embodiment, the color of each light source may also be determined.

Abstract: A curve editor may model a continuous curve as a finite collection of discrete mass points (among which the curve's mass is distributed) and associated springs. The springs may include damped axial springs between pairs of consecutive mass points, and damped bending springs representing interactions between sets of three consecutive mass points. In response to manipulation of the curve at various mass points, the curve editor may determine new positions and/or velocities of one or more mass points using a real time physical simulation of the spring forces acting at mass points involved in the editing operation. The simulation may be dependent on viscous drag forces and/or on constraints applied to individual mass points, angles defined by consecutive mass points, or an absolute direction of a segment between two mass points. Mass points may be added to or removed from the model by adaptive resampling, and the mass redistributed accordingly.

Abstract: Methods and apparatus for construction of an object shape from an image using a light-space graphical model are disclosed. A set of normal vectors for a set of pixels in an image is defined. Each normal vector is defined in terms of an azimuth and a zenith measured in a spherical coordinate system centered on a light source illuminating the image. The zenith of each normal vector is constrained based on an observed shading of a respective pixel. A shape is constructed from the image. Constructing the shape includes minimizing an energy function to specify an azimuth value and a zenith value of each normal vector. Minimizing the energy function further includes constraining the azimuth of each normal vector based on an image gradient of the image at each respective pixel to enforce a coplanar assumption between the image gradient expressed in a three-dimensional space and the respective normal vector.

Abstract: Methods and apparatus for patch-based construction of an object shape from the shading of an image are disclosed. An image is divided into a set of image subregions. For each image subregion, a set of subregion dictionary entries is identified. Each of the set of subregion dictionary entries includes a subregion entry appearance matching an appearance of the respective image subregion and a subregion entry geometry. A set of optimal subregion dictionary entries is identified. Identifying the set of optimal subregion dictionary entries includes minimizing an energy function of the sets of subregion dictionary entries for all image subregions. Each optimal subregion dictionary entry is, for a respective one of the image subregions, a subregion entry associated with a minimum of the energy function. The shape includes a shape construction parameter from a subregion geometry entry of each optimal subregion geometry entry of the set of optimal subregion geometry entries.

Abstract: Systems, methods, and apparatus for simulating natural media painting in a digital painting application (or painting simulation module) may more accurately simulate real world painting techniques than conventional painting simulation applications. The digital painting application (or simulation module) may provide a small set of physically meaningful parameters (e.g., canvas wetness, drying rate, and pickup mix ratio). By setting the values of these parameters (or overriding default values for a selected paint type), the user may better control the appearance of brush strokes made by a virtual paint brush on a digital canvas. For example, the length of a brush stroke, the amount of streaking caused by paint picked up during the brush stroke, and/or the mix of paint deposited from a pickup buffer and a reservoir buffer of a brush model may be affected by changing the values of these parameters, thus allowing users to create different realistic painting effects.

Abstract: Systems, methods, and apparatus for simulating natural media painting in a digital painting application (or painting simulation module) using a two-layer model of a virtual paint brush may more accurately simulate real world painting techniques than conventional painting simulations. A two-layer brush model may include a reservoir buffer and a pickup buffer to separately represent the paint stored in the belly of a paint brush tip and paint that has been picked up on the surface of the brush tip during a brush stoke, respectively. The two-layer brush model may also include methods that automatically control how virtual paint moves between these layers and a digital canvas. In simulations that employ this two-layer brush model, virtual paint may be deposited on the digital canvas directly from both of the buffers. The amount of paint deposited from each buffer (and/or the ratio of the amounts) may be configurable by a user.

Abstract: A method, system, and computer-readable storage medium for simulating bristle brush behavior in an image editing application may use stiffness-height parameterization to determine the height of a brush tool above a canvas during a brush stroke. The determination may be dependent on the pressure applied during the stroke (e.g., using a stylus on a pressure-sensitive tablet), and on the stiffness of the brush bristles. The system may select a standard-stiffness or high-stiffness mapping between stylus pressure values and brush height values dependent whether the bristle stiffness value is above or below a pre-determined threshold. The standard-stiffness mapping may apply a linear function to pressure values to determine height values. Using the high-stiffness mapping, the effect of increased pressure on corresponding brush height values may be reduced as bristle stiffness is increased.

Abstract: A method, system, and computer-readable storage medium are disclosed for determining characteristics of light sources. In one embodiment, an image comprising pixels may be received. The image may be affected by a plurality of light sources including a first light source and a second light source. The first light source and the second light source may overlap. The intensity and direction of each of the plurality of light sources in the image may be determined. In one embodiment, the color of each light source may also be determined.

Abstract: A method, system, and computer-readable storage medium are disclosed for simulating bristle brush behavior and generating vector output from such simulations. User input may represent a stroke made by a paint brush comprising multiple bristles sweeping across a canvas. A vector representation of the brush stroke's effects may be generated by, for each of the plurality of bristles: determining a path along which the bristle has swept, and generating a vector representation of the path along which the bristle has swept (e.g., a set of Bézier curves, or straight line segments). The vector representation of the effects of the brush stroke may comprise the vector representations of the paths along which each of the plurality of bristles has swept. The vector representations of the paths of each bristle sweep may be composited over each other in an image editing application to depict the brush stroke for display and/or for printing.