Abstract: A method for identifying missing map features in an electronic map, involving receiving telemetry probes indicating a geographic location of a mobile computing device, and identifying a subset of telemetry probes corresponding to an existing map feature. The identified subset is then removed from an aggregation of telemetry probes, and the remaining telemetry probes used to generate a density map and identify missing clusters of telemetry probes. A geometry of the missing clusters is determined, and a missing map feature defined from the geometry of the missing cluster. An electronic map may be updated with the missing map feature.

Abstract: A polygon Boolean operation and topology correction algorithm generates valid polygons despite polygon data containing self-intersecting polygons, overlapping polygons, polygons including a chain of holes, and/or polygons including complex intersections. A polygon Boolean operation and topology correction algorithm uses two variants of the Vatti algorithm along with a topology correction algorithm to address problematic areas within input data, such as the overlapping area shared between one or more polygons or a polygon having no area at all. Upon performing a variant of the Vatti algorithm to identify hot pixels within an arrangement of polygons, the polygon Boolean operation and topology correction algorithm runs a second variant of the Vatti algorithm to generate polygons within an integer coordinate system using snap-rounding.

Abstract: Digital data corresponding to a trace by a device is received. The digital data includes location data and time data obtained over a period of time and representing movement of the device. A set of derived values for the plurality of metrics are calculated from the sets of values corresponding to the metrics, and the set of derived values are compared to a binary classification model to determine whether the received digital data represents movement of a first type. The binary classification model was trained using a first set of traces representing the first type of movement and a second set of traces. In response to determining that the digital data represents movement of the first type, the received digital data corresponding to the trace is labelled with the first type of movement.

Abstract: Techniques are described for efficient duplicate label handling. A vector tile is added to a render tree of an electronic map, the vector tile comprising a first set of labels. A vector tile family of the vector tile is identified, each vector tile of the family comprising a second set of labels. For each label of the first set, for each vector tile in the vector tile family, second labels from the second set are identified, and for each identified label, coordinates of the label of the first set are compared to coordinates of the identified label to determine whether the coordinates are within a threshold similarity of each other. Responsive to the determination, the label of the first set of labels is associated with an identifier with which the identified label is associated.

Abstract: Techniques are described for efficiently generating terrain openness involve a digital elevation model comprising a texture representing a first geographic area and at least part of a plurality of mipmap levels representing geographic areas bordering the first geographic area. The texture and mipmap levels include pixels encoding elevation values for locations of geographic areas. For each pixel of the texture, derivatives are determined, as well as an openness factor based at least in part on the elevations at one or more pixels of the mipmap levels. The derivatives and openness factor are added to the texture. A hill shading factor is determined for each pixel based at least in part on the derivatives. An electronic map of the first geographic area is rendered using the openness and hill shading factors of each pixel of the texture. The rendering is sent for display.

Abstract: A method for displaying location information on a display of an electronic device as part of a graphical user interface involves accessing a reference geographical location. The method further involves receiving a set of geographical destinations, each destination of the set of destinations comprising a name and a location. The method further involves determining a set of travel times between the reference geographical location and each of the locations associated with the destinations in the set. The method further involves generating for display in a map display region of the graphical user interface a reference graphical element, a set of isochrone graphical elements, and a set of destination graphical elements.

Abstract: A process, and corresponding system for performing the process, is described herein for visual identification of label collision for a digital map. The process determines a set of labels to be rendered in a visual map corresponding to a digital map. For each label in the set, a label boundary is created around the label. If any of the label boundaries in the set of labels overlap, the process determines a display priority for each of the first label and the second label in an overlapping label pair. In response to the first label in the pair having a higher display priority than the second label in the pair, the boundary for the first label is rendered in a first visual style and the label boundary for the second label in a second visual style. As priorities or properties are changed, the visual map is updated to reflect the changes.

Abstract: Techniques are described for efficient label insertion and collision handling. A bounding geometry for a label to be graphically displayed on a display screen as part of an electronic map is determined, wherein the bounding geometry comprises a circle. The bounding geometry is inserted into a grid index, wherein the grid index represents a viewport of the electronic map. Disjoint regions of the grid index intersected by the bounding geometry are identified, wherein each disjoint region represents a different portion of the viewport. For each intersected disjoint region, it is identified whether there is at least one collision between the bounding geometry and one or more existing bounding geometries in the disjoint region; and responsive to identifying whether there is at least one collision in the intersected disjoint region, a target opacity of the label is set.

Abstract: A process and system allow for visually representing style layer properties of a digital map across various zoom levels. From a style sheet for a digital map, a plurality of style layer properties for a style layer corresponding to the digital map are determined for rendering in the form of a visual map, including various property values for different zoom levels. From these, a zoom level function is generated between pairs of the values for a particular style layer property, by assigning property values (a continuous range or finite set) between the first property value and the second property value in the pair. A visual map based on vector map tiles rendered according to the zoom level function is displayed according to the selected zoom level. As values are changed, the visual map is updated to reflect the changes.

Abstract: Digital data corresponding to a trace by a device is received. The digital data includes a set of values for each of a plurality of metrics. A set of derived values for the plurality of metrics are calculated from the sets of values corresponding to the metrics, and the set of derived values are compared to a machine learning model trained using a plurality of travel modes. A plurality of confidence scores for the derived values are calculated. The plurality of confidence scores correspond to the plurality of travel modes. In response to a confidence score for a first travel mode of the plurality of confidence scores for the plurality of travel modes meeting a threshold value for the first travel mode, the received digital data corresponding to the trace is labelled with the first travel mode.

Abstract: Systems and methods for identifying a visual center of a polygon associated with map data for use in a map application are provided. The method involves receives electronic map data describing a shape with a boundary, and generating a first plurality of cells, each cell corresponding to a respective portion of the shape. The method further involves selecting the first plurality of cells as a selected set of cells to process, and recursively processing the selected set of cells to determine a maximum distance cell that corresponds to a portion of a cell of the first plurality of cells. The maximum distance cell has a highest distance to the boundary of the shape, and is located within the boundary of the shape. An electronic map is provided with an image of the shape and additional data that is displayed at the location of the maximum distance cell within the shape.

Abstract: Disclosed is an online system that generates a density map of a particular location based records received from one or more reporting devices. To this end, the online system determines a relationship between time and a raster density for each unit area in a density map. The determined relationship between time and a raster density may be used to store, and transmit records as parameters of a parametrized function.

Abstract: In an embodiment, a data processing method providing an improvement in filtering telemetry data received from mobile devices comprises receiving, from a mobile device, telemetry data comprising a plurality of probes, each probe identifying a location of the mobile device at a time of the probe, wherein the plurality of probes form first digital trace data identifying a path of the mobile device; determining, for a particular probe of the plurality of probes, a first attribute of the particular probe; determining whether the first attribute of the particular probe satisfies a first threshold; in response to satisfying the first threshold, deleting the particular probe from the plurality of probes and dividing the first digital trace data into second digital trace data and third digital trace data; performing an action using the second digital trace data and the third digital trace data.

Abstract: A data processing method comprising receiving a digital image file comprising a plurality of digital channel datasets corresponding to a plurality of image channels, wherein the digital image file includes an image region and a non-image region; determining a boundary for the image region; for each channel in the plurality of channels, generating a buffer region by using the digital channel datasets, identifying a plurality of pixels along the boundary and for each pixel of the plurality of pixels, copying the pixel one or more times outward into the non-image region in digital memory; and storing a modified digital image file that includes the buffer region.

Abstract: A method comprises identifying, in an electronic map, road data and intersection data, wherein the intersection data specifies an approach and two or more exits from the approach, bounding the approach using a bounding box around the entrance to an approach, identifying, using the bounding box, traces associated with the approach, wherein each trace identifies a path of a vehicle on one or more of the roads, for each trace of the plurality of traces, identifying which of the two or more exits most closely matches the particular trace, generating histograms based on a time period and which of the two or more exits most closely matches each trace of the plurality of traces, determining, using the histograms, whether one or more threshold values associated with one of the two or more exits is satisfied, sending a notification signal when the one or more threshold values is satisfied.