Patent Description:
Processing of details of an image frame, and specifically applying of calculations on the image frame's data, is inherently in contradiction to at least one of computation resources and computation time. The higher the required resolution of frame details the larger is the required computation resources and/or the slower is the computation result. Applying high resolution computation to only a pre-selected portion of an image frame (e.g., a region of interest (ROI)) may shorten the processing result time and/or lower the computation load. However, the selected ROI may accidently not include at least some image details that may be of high importance, thereby the resulting benefit may not balance with the loss of important data.

For example, when the processed image frame is taken from a forward looking imaging device of a running train (for example in order to provide advance warning of threatening obstacles) there is a need for fast processing of the image frame's details along with ensuring that details included in a region encircling the rails forward of the train (e.g., also called 'safety zone' (SZ), or 'gabarit'), with probability of detection (PD) of an obstacle higher than a given threshold and false alarm rate (FAR) lower than a given second threshold.

In European Patent Application <CIT> (<NUM>-<NUM>-<NUM>), systems and methods for detecting an object in a field of view of an imaging device are disclosed. An object may be detected by an imaging device when the object is present along a trajectory in a target scene. In one example, a system includes a memory component to store a plurality of images of the target scene and a processor. The processor is configured to define the trajectory between two locations within the target scene and extract a subset of pixel values from each of successive images corresponding to the trajectory. The extracted subsets of pixel values are processed to detect an object within the target scene. Additional systems and methods are also provided. The document <CIT> discloses a system for alerting a driver of a vehicle of the presence of an obstacle in a track of the vehicle, comprising a sensor mounted on the vehicle for producing at least one sensor signal representative of a predetermined field of view of the track in front of the vehicle, and an obstacle detection device coupled to the sensor for processing the at least one sensor signal produced thereby so as to detect an obstacle in the track and produce an obstacle detect signal consequent thereto. An obstacle avoidance device is mounted in the vehicle and coupled to the obstacle detection device and is responsive to the obstacle detect signal for producing an obstacle avoidance signal. The track is a rail track, the vehicle is a railway engine and the sensor includes a video camera for imaging the track. The resulting image is processed so as to detect a potential obstacle on the tracks allowing the brakes to be applied either manually or automatically.

The present invention provides a system for enhancing a sampling rate of an imager detector for a selected region of interest, the system including: an imaging device; and a processing unit in communication with the imaging device; wherein the imaging device is configured to acquire a plurality of datasets of corresponding plurality of image frames by performing corresponding plurality of image frame handling cycles; wherein the processing unit is configured to define a special region of interest (SROI) in each of at least some of the plurality of the image frames, based on the datasets of the respective image frames; wherein the imaging device is further configured to acquire at least one partial dataset of the SROI, during each of at least some of the plurality of image frame handling cycles and within a residual time between an end of an image frame acquiring time and an end of the respective image frame handling cycle; and wherein the system is further configured to be disposed on a locomotive of a train such that the imaging device faces a direction of travel of the train, and wherein the processing unit further comprises a tracking module configured to: detect rails in each of at least some of the plurality of the image frames; define margins on both sides of the detected rails in each of at least some of the plurality of the image frames; define a safe braking line in each of at least some of the plurality of the image frames, based on a safe braking distance of the train; define a safe zone in each of at least some of the plurality of the image frames, based on the defined margins and the defined safe braking line; and define the SROI in each of at least some of the plurality of the image frames at a distal end of the defined safe zone.

The present invention also provides a method of enhancing a sampling rate of an imager detector for a selected region of interest, the method including: acquiring, by an imaging device, a plurality of datasets of corresponding plurality of image frames by performing corresponding plurality of image frame handling cycles; defining, by a processing unit, a special region of interest (SROI) in each of at least some of the plurality of the image frames, based on the datasets of the respective image frames; acquiring, by the imaging device, at least one partial dataset of the SROI, during each of at least some of the plurality of image frame handling cycles and within a residual time between an end of an image frame acquiring time and an end of the respective image frame handling cycle; detecting, by a tracking module of the processing unit, rails in each of at least some of the plurality of the image frames; defining, by the tracking module, margins on both sides of the detected rails in each of at least some of the plurality of the image frames; defining, by the tracking module, a safe braking line in each of at least some of the plurality of the image frames, based on a safe braking distance of the train; defining, by the tracking module, a safe zone in each of at least some of the plurality of the image frames, based on the defined margins and the defined safe braking line; and defining, by the tracking module, the SROI in each of at least some of the plurality of the image frames at a distal end of the defined safe zone.

These, additional, and/or other aspects and/or advantages of the present invention are set forth in the detailed description which follows; possibly inferable from the detailed description; and/or learnable by practice of the present invention.

For a better understanding of embodiments of the invention and to show how the same can be carried into effect, reference will now be made, purely by way of example, to the accompanying drawings in which like numerals designate corresponding elements or sections throughout.

It will be appreciated that, for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale.

In the following description, various aspects of the present invention are described. For purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the present invention. However, it will also be apparent to one skilled in the art that the present invention can be practiced without the specific details presented herein. Furthermore, well known features can have been omitted or simplified in order not to obscure the present invention. With specific reference to the drawings, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention can be embodied in practice.

Before at least one embodiment of the invention is explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is applicable to other embodiments that can be practiced or carried out in various ways.

Unless specifically stated otherwise, as apparent from the following discussions, it is appreciated that throughout the specification discussions utilizing terms such as "processing", "computing", "calculating", "determining", "enhancing" or the like, refer to the action and/or processes of a computer or computing system, or similar electronic computing device, that manipulates and/or transforms data represented as physical, such as electronic, quantities within the computing system's registers and/or memories into other data similarly represented as physical quantities within the computing system's memories, registers or other such information storage, transmission or display devices. Any of the disclosed modules or units can be at least partially implemented by a computer processor.

The present invention provides a system and method for enhancing a sampling rate of an imaging device for a selected region of interest in an image frame.

The system includes an imaging device and a processing unit.

The imaging device is configured to acquire a plurality of datasets of corresponding plurality of image frames by performing corresponding plurality of image frame handling cycles.

The processing unit is configured to define a special region of interest (SROI) in each of at least some of the plurality of the image frames acquired by the imaging device, based on the datasets of the respective image frames. The SROI may be a region in the image frames in which extended image processing resolution (e.g., spatial resolution) may be needed.

The imaging device is further configured to acquire at least one partial dataset of the SROI, during each of at least some of the plurality of image frame handling cycles and within a residual time between an end of an image frame acquiring time and an end of the respective image frame handling cycle.

Advantageously, the disclosed system and method may enable to increase the rate of acquiring datasets of the SROI within full image frames while maintaining the frame rate of the imaging device at the given frame rate value.

Reference is made to <FIG>, which is a schematic illustration of an image frame <NUM> depicting rails <NUM> with side margins <NUM> and a safe braking line <NUM> defining a safe braking distance range <NUM>, according to some embodiments of the invention. Reference is also made to <FIG>, which is a schematic illustration of image frames 100a, 100b depicting rails <NUM> and a special region of interest (SROI) <NUM> within the image frames, according to some embodiments of the invention.

A safety zone <NUM> (e.g., depicted in <FIG> by light grey color) of a traveling train may be defined as an area with defined margins <NUM> on both sides of rails <NUM> ranging from the train's leading end (e.g., the locomotive of the train) to safe braking distance <NUM> along rails <NUM> forward of the train. Safety zone <NUM> may represent an area in which identified objects may be of a high probability to pose risk to the traveling train.

Typically, safety zone <NUM> may have in image frame <NUM> a shape that narrows from the bottom portion of the imaged area that is close to the bottom of image frame <NUM> as safe zone <NUM> progresses toward the top of image frame <NUM>. Safe braking distance <NUM> may be directly proportional to the traveling speed of the train (and, in a lower degree of importance, to the mechanical condition of the train and the rails and of certain weather aspects).

Horizontal line <NUM> drawn at a distance from safe braking line <NUM> (towards the travelling train) in <FIG> may define a special region of interest (SROI) <NUM> inside safety zone <NUM> in which, due to the distance from the train, extended image processing resolution may be needed, in order to ensure sufficient capability to identify objects that may threaten the train.

SROI <NUM> may, for example, have rectangular shape with width XSROI and height YSROI where the dimension XSROI is parallel to the horizontal dimension Xframe of image frame <NUM> and the dimension YSROI is parallel to the vertical dimension Yframe of image frame <NUM>. The location of SROI <NUM> within image frame <NUM> may be denoted by the <NUM>-dimensional distance of one of its corners from a reference corner of image frame <NUM>. For example, the location of SROI <NUM> within image frame <NUM> may be denoted by the horizontal distance X<NUM> and the vertical distance Y<NUM>.

The size, aspect ratio and location of SROI <NUM> within image frame <NUM> (collectively - SROI parameters) may be determined or selected, for example, so that it encompasses the distal end of safety zone <NUM>. The size of SROI <NUM> may be set so as to balance between the need to provide higher resolution for as large as possible details inside SROI <NUM> and the need to operate within the given performance figures of the system, such as frame rate and maximal data capacity. The rectangular shape of SROI <NUM> may be preferred in systems that, for example, support direct, easy and resources-saving setting of the location and size of SROI <NUM>.

One or more from the following considerations may be relied upon in deciding/defining the parameters of SROI <NUM>: (i) desired object resolution in the SROI, (ii) expected or desired probability of detection and false alarm rate figures, (iii) available computational resources for image processing, (iv) available frame rate of the imaging device, and the like. For example, the vertical dimension and the vertical position of SROI <NUM> may be selected to encompass safe braking line <NUM> and horizontal line <NUM>. The horizontal dimension and the horizontal position of SROI <NUM> may be selected to encompass the entire portion of safety zone <NUM> extending between safe braking line <NUM> and horizontal line <NUM>.

According to some embodiments, SROI <NUM> may be defined in the image frames using a tracking module (e.g., as described below with respect to <FIG>). The tracker module may be configured to define and track the locations in the image frames where rails <NUM> are imaged.

The tracking module may be further configured to define the locations of rails <NUM> in subsequent image frames <NUM> to thereby track the location of SROI <NUM> in image frames <NUM>. For example, <FIG> depicts a first image frame 100a with SROI <NUM> located around the distal end of rails <NUM>, substantially in the middle of first image frame 100a, and second image frame 100b with SROI <NUM> located around the distal end of rails <NUM>, located sideway of the center of second image frame 100b, as a result of the operation of the tracking module.

One way to reach high probability of detection of obstacles that may threaten the train and/or low false alarm rate thereof is to decrease the probability of events by selecting SROI <NUM> that is smaller than the entire image frame <NUM>. The disadvantage of this is that events outside SROI <NUM> will not be detected and some of them might be too important to be mis-detected.

Another way to reach high probability of detection of obstacles that may threaten the train and/or low false alarm rate thereof is to increase the sampling Band Width (BW) by increasing the frame rate of the imaging device. The consequences of this may include an increased load on the computational resources (e.g., processing unit) of the system.

According to some embodiments, the disclosed system and method may enable to increase the sampling rate of SROI <NUM> within full image frames while maintaining the frame rate of the imaging device at a given frame rate (e.g., as described below with respect to <FIG>).

In this manner, the disclosed system and method may, for example, enable increasing the probability of detection of obstacles that may threaten the train and/or decreasing false alarm rate thereof without substantially loading the computation resources and enabling use of existing interface of the imaging device.

Reference is now made now to <FIG>, which is a schematic time graph <NUM> of a common image frame handling by an imaging device.

Image frames are typically being acquired at a given frame rate (e.g., interchangeably referred hereinafter as "FR") with a given cycle time <NUM> between the image frames (e.g., interchangeably referred hereinafter as "tcyc"), wherein given cycle time <NUM> is inversely proportional to the given frame rate (e.g., tcyc=<NUM>/FR). Typically, acquiring of each image frame lasts an image frame acquiring time <NUM> (e.g., interchangeably referred hereinafter as "Δtat") and includes acquiring of data items (e.g., datasets) according to a maximal data capacity (DCM) <NUM> per time unit (e.g., pixel/time) of the imaging device.

Accordingly, the amount of acquired data items (e.g., interchangeably referred hereinafter as "pixel per frame" or "PPF") at each Δtat in normal mode of operation of the imaging device may be expressed by Equation <NUM> and the amount of acquired data items per second (e.g., interchangeably referred hereinafter as "DPS") at the given frame rate (FR) of the imaging device may be expressed by Equation <NUM>: <MAT> <MAT>.

Typical imaging device may have a certain maximum data handling capacity which involves image photons accumulation at an imager thereof, image data transfer from the imaging device, image data saving and image data processing. The specific performance of the imaging device may define image frame acquiring time <NUM> (Δtat) needed to acquire the data items of each full image frame. Typically, image frame acquiring time <NUM> (Δtat) is smaller than given cycle time <NUM> (tcyc), which stems that there is a residual time <NUM> (e.g., interchangeably referred hereinafter as "tres") during each given cycle time <NUM> (e.g., tcyc) at which the imaging device is not busy.

Reference is now made to <FIG>, which is a time graph <NUM> of an image frame handling, according to embodiments of the present invention.

A handling cycle of an image frame may last a given cycle time <NUM> (e.g., tcyc) and may include an image frame acquiring time <NUM> (e.g., Δtat) during which data items (e.g., dataset) of a full image frame are being acquired and a residual time <NUM> (e.g., tres) during which the imaging device is not busy. For example, given cycle time <NUM>, image frame acquiring time <NUM> and residual time <NUM> may be similar to given cycle time <NUM>, image frame acquiring time <NUM> and residual time <NUM>, respectively, described above with respect to <FIG>.

According to embodiments, during residual time <NUM> of at least one image frame handling cycle, at least one additional cycle of acquiring data items of a selected portion of the image frame may be performed (e.g., as shown in <FIG>). The data items acquired from the selected portion of the image frame are interchangeably referred hereinafter as "partial data items" or "partial dataset" or "partial datasets". The acquiring of the partial data items / partial datasets of the selected portion of the image frame may last a partial acquiring time <NUM> (interchangeably referred hereinafter as "Δtpat"). The selected portion of the image frame may be a region in the image frames in which extended image processing resolution may be needed. The selected portion of the image frame may, for example, be a special region of interest in the image frame, such as SROI <NUM> described above with respect to <FIG> and <FIG>.

Partial acquiring time <NUM> (Δtpat) required for acquiring partial data items of the selected portion of the image frame may depend on, for example, the size of the selected portion and the acquiring data rate (pixel/ms). Assuming that the acquiring data rate of the selected portion is the same as the acquiring data rate of the full image frame acquiring, the ratio Δtpda/Δtda equals to the ratio of the area of the selected portion of the image frame to the area of the full image. In some embodiments, the selected portion of the image frame is significantly smaller as compared to the full image frame such that Δtpda<<Δtda (e.g., as shown in <FIG>). For example, the selected portion of the image frame may be 200x200 pixels as compared to, for example, a full image frame that has 1024x720 pixels. In this example, the partial amount of data items acquired from the selected portion of the image frame may be only <NUM>% of the amount of data items that need to be acquired from the full image frame.

Accordingly, one or more additional cycles of acquiring partial data items / partial datasets of the selected portion of the image frame may be performed during residual time <NUM> of each of one or more image frame handling cycle, thereby increasing the image resolution for details in the selected portion of the image frame, without changing the frame rate or having to exceed a given maximal data capacity (DCM) <NUM> (like DCM <NUM> described above with respect to <FIG>) of the imaging device.

For example, for the embodiment depicted in <FIG> the amount of acquired data items per second (DPS) at the given frame rate (FR) of the imaging device may be expressed by Equation <NUM>: <MAT>.

Reference is now made to <FIG>, which is a schematic illustration of a system <NUM> for enhancing a sampling rate of an imager detector for a selected region of interest in an image frame, according to some embodiments of the invention.

System <NUM> includes an imaging device <NUM> and a processing unit <NUM>. System <NUM> is disposed on a locomotive of a train such that imaging device <NUM> faces the direction of travel of the train. However, system <NUM> may be applicable in other applications as well (such as, for example, automobiles, etc.).

Imaging device <NUM> is configured to acquire a plurality of datasets of corresponding plurality of image frames by performing corresponding plurality of image frame handling cycles. For example, the image frames acquired by imaging device <NUM> may be similar to image frame <NUM> described above with respect to <FIG>.

Processing unit <NUM> is configured to define a special region of interest (SROI) in each of at least some of the plurality of the image frames acquired by imaging device <NUM>, based on the datasets of the respective image frames. The SROI may be a region in the image frames in which extended image processing resolution may be needed. For example, the SROI may be SROI <NUM> described above with respect to <FIG> and <FIG>.

Imaging device <NUM> is further configured to acquire at least one partial dataset of the SROI, during each of at least some of the plurality of image frame handling cycles and within a residual time between an end of an image frame acquiring time and an end of the respective image frame handling cycle (e.g., as described above with respect to <FIG>).

Reference is now made to <FIG>, which is a flowchart of a method <NUM> of for enhancing a sampling rate of an imager detector for a selected region of interest in an image frame, according to some embodiments of the invention.

Method <NUM> may be implemented by system <NUM> (e.g., as described above with respect to <FIG>), which may be configured to implement method <NUM>. It is noted that method <NUM> is not limited to the flowcharts illustrated in <FIG> and to the corresponding description.

Method <NUM> includes acquiring, by an imaging device, a plurality of datasets of corresponding plurality of image frames by performing corresponding plurality of image frame handling cycles (stage <NUM>). For example, imaging device <NUM> described above with respect to <FIG>.

Method <NUM> includes defining, by a processing unit, a special region of interest (SROI) in each of at least some of the plurality of the image frames acquired by the imaging device, based on the datasets of the respective image frames (stage <NUM>). For example, the SROI described above with respect to <FIG>.

Method <NUM> includes acquiring, by the imaging device, at least one partial dataset of the SROI, during each of at least some of the plurality of image frame handling cycles and within a residual time between an end of an image frame acquiring time and an end of the respective image frame handling cycle (stage <NUM>) (e.g., as described above with respect to <FIG>).

Advantageously, system <NUM> and method <NUM> may enable to increase the rate of acquiring datasets of the SROI within full image frames while maintaining the frame rate of the imaging device at the given frame rate.

Reference is now made to <FIG>, which is a schematic illustration of an optical system <NUM> for an obstacle detection by a moving vehicle <NUM>, such as a train and capable of enhancing a sampling rate of an imager detector for a selected region of interest in an image frame, according to some embodiments of the invention.

System <NUM> includes an imaging device <NUM> and a processing unit <NUM>. System <NUM> is disposed on a locomotive <NUM> of a train <NUM> such that imaging device <NUM> faces the direction of travel of train <NUM>.

Imaging device <NUM> is configured to acquire a plurality of datasets of corresponding plurality of image frames by performing corresponding plurality of image frame handling cycles. For example, the image frames acquired by imaging device <NUM> may be similar to image frame <NUM> described above with respect to <FIG> and <FIG>. In some embodiments, imaging device <NUM> is an infrared detector.

The image frames may depict at least rails <NUM> in front of moving locomotive <NUM>. The image frame handling cycles may be performed by imaging device <NUM> at a given frame rate and with a given cycle time between the image frames. For example, the given frame rate FR, given cycle time <NUM> (e.g., tcyc) and the image frame handling cycles as described above with respect to <FIG>.

Processing unit <NUM> includes a tracking module <NUM>.

Tracking module <NUM> is configured to detect rails in each of at least some of the plurality of the image frames acquired by imaging device <NUM>. For example, the rails may be such as rails <NUM> described above with respect to <FIG>.

The rails may be detected in the image frames using any technique known in the art. For example, the rails may be detected based on temperature differences between the rails and their background (e.g., when imaging device <NUM> is the infrared detector).

Tracking module <NUM> is configured to define margins on both sides of the detected rails in each of at least some of the plurality of the image frames. For example, the margins may be margins <NUM> described above with respect to <FIG>. The margins may be defined according to efficiency/quality of the rail's detection. For example, the better detection of the rails the smaller the distance of the margins to the rails may be. Yet in this example, if the rails are not well detected, the margins may be set at a larger distance from the rails to compensate for poor rails detection.

Tracking module <NUM> is configured to define a safe braking line in each of at least some of the plurality of the image frames, based on a safe braking distance of train <NUM>. For example, the safe braking line and the safe braking distance may be similar to safe braking line <NUM> and safe braking distance <NUM> described above with respect to <FIG>. The safe braking distance may be determined based on, for example, a speed of train <NUM>.

Tracking module <NUM> is configured to define a safe zone in each of at least some of the plurality of the image frames, based on the defined margins and the defined safe braking line. For example, the safety zone may safety zone <NUM> described above with respect to <FIG>.

Tracking module <NUM> is configured to define a special region of interest (SROI) in each of at least some of the plurality of the image frames at a distal end of the defined safe zone. For example, the SROI may be SROI <NUM> described above with respect to <FIG>. The SROI may be a zone in which, due to the distance from train <NUM>, extended image processing resolution may be needed, in order to ensure sufficient capability to detect objects that may threaten train <NUM>.

In some embodiments, tracking module <NUM> may be configured to define the SROI in subsequent image frames to thereby track the location of the SROI in the image frames thereof (e.g., as described above with respect to <FIG>).

According to some embodiments, processing unit <NUM> may include an obstacle detection module <NUM>. Obstacle detection module <NUM> may be configured to analyze the datasets of full image frames and/or the partial datasets of the SROI in the full image frames and to detect, based on the analysis thereof, a potential object/obstacle on rails <NUM> and/or in the defined SROI.

Reference is now made to <FIG>, which is a flowchart of a method <NUM> of an obstacle detection by a moving train while enhancing a sampling rate of an imager detector for a selected region of interest in an image frame, according to some embodiments of the invention.

Method <NUM> may be implemented by system <NUM>, which may be configured to implement method <NUM>. It is noted that method <NUM> is not limited to the flowcharts illustrated in <FIG> and to the corresponding description. For example, in various embodiments, method <NUM> needs not move through each illustrated box or stage, or in exactly the same order as illustrated and described.

Method <NUM> includes acquiring, by an imaging device, a plurality of datasets of corresponding plurality of image frames by performing corresponding plurality of image frame handling cycles (stage <NUM>). For example, the imaging device may be like imaging device <NUM> described above with respect to <FIG>.

Method <NUM> includes defining, by a tracking module of a processing unit, a special region of interest (SROI) in each of at least some of the plurality of the image frames acquired by the imaging device, based on the datasets of the respective image frames (stage <NUM>). For example, the tracking unit and the processing unit may be like tracking unit <NUM> and processing unit <NUM> described above with respect to <FIG>. The SROI may be like SROI <NUM> described above with respect to <FIG> and <FIG>.

Method <NUM> further includes detecting rails in each of at least some of the plurality of the image frames (stage <NUM>) (e.g., as described above with respect to <FIG>).

Method <NUM> further includes defining margins on both sides of the detected rails in each of at least some of the plurality of the image frames (stage <NUM>) (e.g., as described above with respect to <FIG>).

Method <NUM> further includes defining a safe braking line in each of at least some of the plurality of the image frames, based on a safe braking distance of the train (stage <NUM>) (e.g., as described above with respect to <FIG>).

Method <NUM> further includes defining a safe zone in each of at least some of the plurality of the image frames, based on the defined margins and the defined safe braking line (stage <NUM>) (e.g., as described above with respect to <FIG>).

Method <NUM> further includes defining a special region of interest (SROI) in each of at least some of the plurality of the image frames at a distal end of the defined safe zone (stage <NUM>) (e.g., as described above with respect to <FIG>).

In some embodiments, method <NUM> may further include defining the SROI in subsequent image frames and thereby tracking the location of the SROI in the image frames thereof (stage <NUM>) (e.g., as described above with respect to <FIG>).

Method <NUM> includes acquiring, by the imaging device, at least one partial dataset of the SROI, during each of at least some of the plurality of image frame handling cycles and within a residual time between an end of an image frame acquiring time and an end of the respective image frame handling cycle (stage <NUM>) (e.g., as described above with respect to <FIG> and <FIG>).

According to some embodiments, method <NUM> may include analyzing, by an obstacle detection module of the processing unit, the datasets of full image frames and/or the partial datasets of the SROI in the full image frames and to detect, based on the analysis thereof, a potential object/obstacle on the rails and/or in the defined SROI (stage <NUM>). For example, the obstacle detection module like obstacle detection module <NUM> described above with respect to <FIG>.

Advantageously, system <NUM> and method <NUM> may enable to increase the sampling rate of SROI <NUM> within full image frames while maintaining the frame rate of the imaging device at a given frame rate (e.g., as described below with respect to <FIG>). In this manner, system <NUM> and method <NUM> may enable increasing the probability of detection of obstacles that may threaten the train and/or decreasing false alarm rate thereof without substantially loading the computation resources and enabling use of existing interface of the imaging device.

According to some embodiments described above, higher image resolution for a selected portion of an image frame may be obtained without changing a given frame rate or data capacity of an imaging device. The size of the selected portion and its location within the image frame may be determined or dictated. According to some embodiments, the size and location of the selected portion in the image frame may be set to meet a special region of interest (SROI) for which higher image resolution may be needed.

For example, for a system usable for monitoring rails track of a train and providing advance warning of obstacles near or on the rails, enhanced image resolution may be required for a portion of the image which includes a distal portion of rails detected in the image frames (e.g., as described above with respect to <FIG> and <FIG>, <FIG> and <FIG>). In order to decide the location and size of the SROI, a tracking module may be used. The tracking module may be a graphical processing unit that tracks the presence of rails in the image frame. Such tracking module may be embodied as program running on a computer handling the image processing. For example, if the proximal ends of the rails in the image frame (typically close to the middle of the lower end of the image, with noticeable presence) are tracked upwardly the image frame, the location of the distal ends of the rails within the image frame may be detected using relatively low additional computation load. The result of the tracking of the distal ends of the train rails within the image frame may then be translated to the location and size of the SROI.

Aspects of the present invention are described above with reference to flowchart illustrations and/or portion diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each portion of the flowchart illustrations and/or portion diagrams, and combinations of portions in the flowchart illustrations and/or portion diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or portion diagram or portions thereof.

These computer program instructions can also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or portion diagram portion or portions thereof. The computer program instructions can also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or portion diagram portion or portions thereof.

The aforementioned flowchart and diagrams illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each portion in the flowchart or portion diagrams can represent a module, segment, or portion of code, which includes one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the portion can occur out of the order noted in the figures. For example, two portions shown in succession can, in fact, be executed substantially concurrently, or the portions can sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each portion of the portion diagrams and/or flowchart illustration, and combinations of portions in the portion diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

In the above description, an embodiment is an example or implementation of the invention. The various appearances of "one embodiment", "an embodiment", "certain embodiments" or "some embodiments" do not necessarily all refer to the same embodiments. Although the invention can be described herein in the context of separate embodiments for clarity, the invention can also be implemented in a single embodiment. The disclosure of elements of the invention in the context of a specific embodiment is not to be taken as limiting their use in the specific embodiment alone. Furthermore, it is to be understood that the invention can be carried out or practiced in various ways and that the invention can be implemented in certain embodiments other than the ones outlined in the description above.

Claim 1:
A system for enhancing a sampling rate of an imager detector for a selected region of interest, the system comprising:
an imaging device (<NUM>); and
a processing unit (<NUM>) in communication with the imaging device;
wherein the imaging device is configured to acquire a plurality of datasets of corresponding plurality of image frames by performing corresponding plurality of image frame handling cycles;
wherein the processing unit is configured to define a special region of interest, SROI, (<NUM>) in each of at least some of the plurality of the image frames, based on the datasets of the respective image frames;
wherein the imaging device is further configured to acquire at least one partial dataset of the SROI, during each of at least some of the plurality of image frame handling cycles and within a residual time (<NUM>) between an end of an image frame acquiring time (<NUM>) and an end of the respective image frame handling cycle; and wherein the system is further configured to be disposed on a locomotive of a train such that the imaging device faces a direction of travel of the train, and wherein the processing unit further comprises a tracking module configured to:
detect rails (<NUM>) in each of at least some of the plurality of the image frames;
define margins (<NUM>) on both sides of the detected rails in each of at least some of the plurality of the image frames;
define a safe braking line (<NUM>) in each of at least some of the plurality of the image frames, based on a safe braking distance (<NUM>) of the train;
define a safe zone (<NUM>) in each of at least some of the plurality of the image frames, based on the defined margins and the defined safe braking line; and
define the SROI in each of at least some of the plurality of the image frames at a distal end of the defined safe zone.