WO2017055082A1

WO2017055082A1 - A child monitoring sub-system and a method of video processing a video stream of a camera of a child monitoring system

Info

Publication number: WO2017055082A1
Application number: PCT/EP2016/071626
Authority: WO
Inventors: Eddy Louis Ursula DEJONG
Original assignee: Koninklijke Philips N.V.
Priority date: 2015-09-30
Filing date: 2016-09-14
Publication date: 2017-04-06

Abstract

A child monitoring sub-system comprising a camera (110) and a video processing unit (120) is provided. The camera provides a video stream comprising a series of video images. The video processing unit comprises an input interface, a detection module, a video processing module (130) and an output interface. The input interface receives the video stream. The detection module detects relative orientation of the child with respect to the video images. The video processing module generates from the received video stream an output video stream comprising a series of output images. The video processing module operates in a vertical mode or in a horizontal mode depending on a mode signal. In the vertical mode, the processing module generates vertically oriented output images. In the horizontal mode, the processing module generates horizontally oriented output images. The output interface provides the output video stream to a presentation device.

Description

A child monitoring sub-system and a method of video processing a video stream of a camera of a child monitoring system

FIELD OF THE INVENTION

The invention relates to a child monitoring sub-system for generating an output video stream for a presentation device of a child monitoring system. The invention also relates to a child monitoring system comprising the child monitoring sub-system.

The invention further relates to a method and a computer program product for video processing video images of a child monitoring sub-system to generate an output video stream for a presentation device of a child monitoring system.

BACKGROUND OF THE INVENTION

Traditional child monitoring systems wirelessly transmit a video stream from a room of a child to be monitored to a dedicated display device. Such traditional child monitoring systems have a camera, a video processor, a wireless video transmitter, a wireless video receiver, and a display device. The camera, the video processor and the wireless video transmitter are provided in a so-termed child unit which may be placed, for example, close to an infant bed of the child to be monitored. A parent unit comprises the wireless video receiver and the display device. Often, the camera obtains a video stream comprising a series of images having a relatively high resolution. The video stream also includes an audio stream that is aligned in time with the video stream. The bandwidth of the wireless transmission technology may not be sufficient for the video stream with images of relatively high resolution and, therefore, the resolution is lowered in the video processor. The resolution of the dedicated display device is typically lower than the resolution of the camera. The resolution of the video camera and the resolution of the display device are defined by the number of pixels of the recorded or presented images in a horizontal direction and in a vertical direction.

Published PCT application WO2009/004567A2 discloses a child monitoring system in which an MPEG-4 compression technique is used in combination with

transmission of the data in accordance with the Digital Enhanced Cordless Telecommunications (DECT) standard. According to the PCT application, this provides a robust communication of the video stream.

In practical situations, it has been found that the above discussed child monitoring systems have disadvantages. For example, how well the child is shown on the parent unit strongly depends on where the camera is placed with respect to the infant bed. This means that a parent has to try different positions and check for each different position, whether the view on the parent unit shows the child to be monitored well. In particular, when there is only one suitable location for the camera, for example, on a single cupboard in front of the infant bed, it is not guaranteed that the child to be monitored may be well seen on the display o f the parent unit.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a child monitoring sub-system for use in a child monitoring system that enables the generation of a video stream for a presentation device of the child monitoring system that provides a better view of the child to be monitored.

For this purpose, according to an aspect of the invention, a child monitoring sub-system of a child monitoring system is provided. The child monitoring sub-system is for generating an output video stream. The child monitoring sub-system comprises a camera and a video processing unit. The camera is configured to provide a video stream of a child to be monitored, the video stream comprising a series of video images. The video processing unit comprises an input interface, a detection module, a video processing module and an output interface. The input interface is for receiving the video stream. The detection module is for detecting a relative orientation of the child with respect to the video images, and for generating a corresponding mode signal for indicating a vertical mode or a horizontal mode. The video processing module is configured to generate from the received video stream an output video stream comprising a series of output images. The video processing module is configured to operate in the vertical mode or in the horizontal mode depending on the mode signal. In the vertical mode, the processing module generates vertically oriented output images, and in the horizontal mode, the processing module generates horizontally oriented output images. The output interface is for providing the output video stream to a presentation device of the child monitoring system.

For this purpose, according to another aspect of the invention, a method of video processing a video stream of a camera of a child monitoring system to generate an output video stream for a presentation device of the child monitoring system is provided. The method comprises: i) receiving a video stream from the camera, the video stream comprising a series of video images of a child to be monitored; ii) detecting a relative orientation of the child with respect to the video images; iii) generating a corresponding mode signal for indicating a vertical mode or a horizontal mode, iv) receiving the mode signal; v) generating an output video stream from the received video stream, the output video stream comprising a series of output images, the generation being performed in the vertical mode or in the horizontal mode depending on the received mode signal, in the vertical mode, vertically oriented output images, in the horizontal mode, horizontally oriented output images; vi ) providing the output video stream to the presentation device.

With the measures of the above discussed aspects of the invention, it is possible to generate the output video stream in which the output images are the vertically oriented images or the horizontally oriented images. One of the orientations may be preferred because it better shows the child to be monitored. Subsequently, the presentation device receives the output video stream and presents the horizontally oriented output images or the vertically oriented output images on a display. Thus, the child monitoring sub-system enables that the child to be monitored can be best seen on the presentation device. In other words, the child monitoring sub-system optimizes the view of the child.

For a better view of the child, the output images may be mostly filled with pixels of the child. The video processing module may be configured to operate in the vertical mode if the output images comprise more pixels of the child in the vertical direction than in the horizontal direction. Alternatively the video processing module may be configured to operate in the horizontal direction if the output images comprise more pixels of the child in the horizontal direction than in the vertical direction.

The user of the child monitoring system may rotate the orientation of the display according to the orientation of the output images of the output video stream if that is more convenient for the user. It is, for example, an insight of the inventors that the parents have the better view of the child to be monitored when the camera is located at a left side or at a right side of an infant bed and the output video stream comprises the horizontally oriented video images. Accordingly, the child may be better seen when the camera is located at a foot or at a head of the infant bed and the output video stream comprises the vertically oriented video images.

A horizontally oriented image has more pixels in a horizontal direction than in a vertical direction. In other words, the horizontally oriented image is larger in the horizontal direction than in the vertical direction, i.e., has a larger width than height. A vertically oriented image has more pixels in the vertical direction than in the horizontal direction. In other words, the vertically oriented image is larger in the vertical direction than in the horizontal direction, i.e., has a larger height than width.

In an embodiment, if the camera provides the video stream with the video images having a larger width than height and if the video processing module is in the vertical mode, the video processing module rotates the video images. In an embodiment, if the camera provides the video stream with the video images having height than width and if the video processing module operates in the horizontal mode, the video processing module rotates the video images. As will be discussed later, in certain embodiments, the video processing module may also create a horizontal crop or a vertical crop of the video images, and/or the video processing module may scale the horizontal crop or the vertical crop, and/or the video images.

Optionally, the video processing unit comprises a detection module for generating the mode signal. The detection module also receives the received video stream and detects in the video images whether the horizontally oriented output images or the vertically oriented output images provide a better view of the child to be monitored. The detection module generates the mode signal in dependence of the detection. Thus, on basis of the detection and/or recognition technologies, the mode signal is generated and the output images are adapted automatically to the horizontally oriented output images or the vertically oriented output images. Thereby, the child monitoring system comprising the child monitoring sub-system is made more user- friendly.

Optionally, the detection module detects in the video images at least one of a relative position of the child, a relative orientation of a body of the child, relative positions of elements of a bed in which the child to be monitored lies, and a relative orientation of the elements of the bed in which the child to be monitored lies. On the basis of the detected relative positions and the relative orientations, the detection system is able to decide whether the child is better visible in the output images, when the vertically oriented output images are used or when the horizontally oriented output images are used. If it is known where in the video images the child is located, and how the child is oriented with respect to the video images, the detection module is able to decide whether the mode signal should indicate the vertical mode or the horizontal mode. When the child lies in the bed and the orientation of the child (seen along the longitudinal axis of the body of the child) follows, for example, a horizontal direction, the detection module may decide that the horizontal mode is more appropriate. The detection module may use, for example, image recognition techniques to detect a child's face and/or the child's body.

When the child is sleeping under a blanket, it may be relatively difficult to recognize a significant part of the body of the child in the video images. Consequently, it may be relatively difficult to recognize the position and/or the orientation of the child. Therefore, it may also be advantageous to detect the elements of the bed in which the child to be monitored lies because it defines a sort of envelope around the possible locations where the child may be present. For example, it may be relatively easy to recognize upper beams or bars of the infant bed. The bed in which the child lies may be an infant bed, a cot or a crib and may also be a bed for the child that is older than a baby, and must also be monitored. It is to be noted that if the child's face may be recognized in the video images, a lot of information about the relative orientation of the child may be obtained from the relative position and the relative orientation of the child's face.

Optionally, the child monitoring sub-system comprises a mode selection input module which is capable of receiving a preference with respect to the horizontally oriented output images or the vertically oriented output images from the user. The mode selection signal is generated on the basis of the received preference. Thus, this optional embodiment allows the user to influence the mode in which the video processing module operates, and thereby, the user- friendliness of the child monitoring sub-system is enhanced. The mode selection input module may be a hardware element which allows the user to provide its preference by selecting, for example, a switch that relates to a specific orientation. The mode selection input module may also be formed by a combination of a touch screen (on which for example, also the output video stream is displayed) and a piece of software. Such

combination may generate a graphical selection user interface on the touch screen and the software may be able to transform the received touches to the touch screen into the mode signal at the moment in time when the graphical selection user interface is shown on the touch screen and the user touches the touch screen.

Optionally, the video processing module is also able to create the crop of the video images. The crops of the video images are, in accordance with the mode signal, vertically oriented images or vertically oriented images. The video processing module is also configured to provide the crop of the video images as the output images of the output video stream. By cropping the video images, irrelevant parts of the video images may be omitted and only the relevant part may be selected for the output images. Thereby, a better view of the child to be monitored may be obtained. The use of cropping may also be used in situations wherein the camera has a higher resolution than the screen of the presentation device. The crop may have a size (height x width expressed in a number of pixels) defined by the resolution of the display of the presentation device. As will be discussed hereinafter, the crop may also have a height and a width other than the resolution of the display of the presentation device.

Optionally, if the child monitoring sub-system comprises the detection module and the video processing module is able to crop the video images, the detection module is also able to detect in which region of the video images the child is present and the video processing module is configured to select an area of the video images for the crop of the video images on the basis of the detected region. This optional embodiment ensures that the output images show at least the child and enables the selection of the area of the video images, such that, the child is best seen in the output images.

Optionally, the video processing module is also configured to scale the horizontally oriented output images or the vertically oriented output images to a required size or a resolution of the output images. It is to be noted that this also applies to the output images that are the crop of the video images. It may be possible, for example, that the video images or the crop of the video images have a resolution higher than the required size or the resolution of the output images and then scaling is useful for reducing the size of the images to an appropriate size. It may also be possible that the crop of the video images has the resolution lower than the required size or the resolution of the output images and then scaling is useful for increasing the size of the images to the appropriate size. Well known scaling techniques may be used, for example, based on a linear interpolation, a cubic interpolation and a Lanczos interpolation.

Optionally, the video images have a first resolution of a first number of pixels and the output images have a second resolution of a second number of pixels. The second number of pixels is smaller than the first number of pixels. In some monitoring system, because of the capabilities of video transmission via a wireless connection, the output images have a lower resolution. The resolution defines the number of distinct pixels in each dimension of the images.

According to an aspect of the invention, a child monitoring system is provided which comprises one of the embodiments of the above discussed child monitoring subsystem, and which comprises a presentation device. The presentation device comprises a display for displaying the output video stream and comprises a video stream input for receiving the output video stream of the video processing unit. The presentation device may be a dedicated presentation device which is often a so-termed parent unit of the child monitoring system. The presentation device may also be another type of apparatus which comprises a display, such as, for example, a television, a mobile phone, a laptop computer or a tablet computer.

Optionally, the camera has the first resolution and the presentation device has the second resolution.

Optionally, the child monitoring system comprises a video transmitting module and a video receiving module for providing a wireless video connection between the two devices. The wireless video connection may be provided in between the camera and the video processing unit for wirelessly transmitting the video stream recorded by the camera. The wireless video connection may also be provided in between the video processing unit and the presentation device for transmitting the output video stream generated in the video processing unit. In this embodiment, the child monitoring system is often subdivided in a so- termed child unit and a so-termed parent unit. The child unit comprises the camera and the video transmitting unit. The parent unit comprises the presentation device and the video receiving unit. It may be possible that the video processing unit is provided in the child unit or in the parent unit. For example, if the applied wireless technology does not allow the transmission of high resolution images, the video processing unit may be provided in the child unit and then the video processing unit may also crop or scale the video images of the video stream of the camera to lower resolution output images. For example, if the applied wireless technology allows the transmission of high resolution images and the parent unit has enough processing power (for example, when a tablet computer or a laptop computer is used), then the video processing unit may be integrated with the presentation device in one housing (and, for example, the processor or the video processor of the tablet computer or the laptop computer performs the operations of the video processing unit).

According to an aspect of the invention, a computer program product for video processing video images of a child monitoring system generates an output video stream for a presentation device of the child monitoring system. The computer program is operative to cause a processor to perform the method that has been discussed above.

Further embodiments of the device and method according to the invention are given in the appended claims, disclosure of which is incorporated herein by reference. BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention will be apparent from and elucidated further with reference to the embodiments described by way of example in the following description and with reference to the accompanying drawings, in which

Fig. 1 schematically shows an embodiment of a child monitoring sub-system, Fig. 2 schematically shows another embodiment of a child monitoring subsystem,

Figs. 3 and 4 both schematically show further embodiments of a child monitoring sub-system,

Fig. 5 schematically shows an embodiment of a child monitoring system comprising an embodiment of the child monitoring sub-system and a presentation device,

Figs. 6a and 6b schematically show embodiments of video images of a video stream recorded by a camera and examples of output images and/or crops of the video images,

Fig. 7 schematically shows a method of video processing video images of a child monitoring system, and

Fig. 8 schematically shows a data carrier on which a computer program is stored.

The figures are purely diagrammatic and not drawn to scale. In the Figures, elements which correspond to elements already described may have the same reference numerals.

DETAILED DESCRIPTION OF EMBODIMENTS

Fig. 1 schematically shows an embodiment of a child monitoring sub-system 100. The child monitoring sub-system 100 comprises a camera 110 and a video processing unit 120.

In use, the camera 110 provides a video stream that comprises a series of video images. The video stream is of an environment on which the camera 110 is focused. In a practical embodiment, the parents of a child to be monitored place the camera 110 in the area or environment where the child to be monitored is present and focus the camera 110 on the area where the child to be monitored is present. Thus, if the camera 110 is focused on this area, the video stream comprises video images in which the child to be monitored is present. Depending on the camera 110, the video images of the video stream have a horizontal orientation, a vertical orientation or they are square images. A horizontally oriented image has more pixels in a horizontal direction than in a vertical direction. In other words, the horizontally oriented image is larger in the horizontal direction than in the vertical direction, i.e., has a larger width than height. A vertically oriented image has more pixels in the vertical direction than in the horizontal direction. In other words, the vertically oriented image is larger in the vertical direction than in the horizontal direction, i.e., has a larger height than width.

The video processing unit 120 comprises an input interface 122, a video processing module 130 and an output interface 124. The input interface 122 is coupled to the camera 110, and at the input interface 122, the video stream is received. The video stream may be transmitted towards the input interface 122 via a wired or wireless signal or any other appropriate signal. The signal comprising the video stream may be coded according to an appropriate video encoding technology which may be determined by the capabilities of the camera 110. For example, the used video encoding technology and the used transmission technology is capable of transmitting a specific number of images per second, each having a specific resolution, wherein the specific number of images per second of the specific resolution is determined by the capabilities, or even the maximum capabilities, of the camera 110. The resolution defines the number of distinct pixels in each dimension of the images.

In use, the video processing module 130 generates an output video stream comprising a series of output images on basis of the video stream received at the input interface 122. The video processing module 130 is capable of operating in at least two different operational modes, namely, in a vertical mode or in a horizontal mode. The video processing module 130 receives a mode signal 132 which indicates the operational mode in which the video processing module has to operate. In the vertical mode, the video processing module 130 generates vertically oriented output images on basis of the video stream received at the input interface 122. In the horizontal mode, the processing module 130 generates horizontally oriented output images on basis of the video stream received at the input interface 122. A series of generated output images form the output video stream.

With the discussed combination of features, it is possible to generate the output video stream in which the output images are the vertically oriented images or the horizontally oriented images. One of the orientations may be preferred because it better shows the child to be monitored. The child may be better shown when the output image comprises more pixels of the child than pixels of the background or surrounding objects. For a better view of the child, the output images may be mostly filled with pixels of the child. Subsequently, a presentation device receives the output video stream and presents the horizontally oriented output images or the vertically oriented output images on a display. For example, if the output image comprises more pixels of the child in a horizontal direction than in a vertical direction, the video processing module operates in the horizontal mode. In the latter example, the presentation device presents horizontally oriented output images. If the output image comprises more pixels of the child in a vertical direction than in a horizontal direction, the video processing module operates in the vertical mode. In the latter example, the presentation device presents vertically oriented output images. It might be useful for a user to adapt the orientation of the display of the presentation device to the orientation of the output images of the output video stream. Thus, the above discussed child monitoring sub- system 100 enables that the child to be monitored can be best seen on the presentation device. It is, for example, an insight of the inventors that the parents have a better view of the child to be monitored when the camera is located at a left side or at a right side of an infant bed and the output video stream comprises the horizontally oriented video images. Accordingly, the child may be better seen when the camera is located at a feet end or at a head end of the infant bed and the output video stream comprises the vertically oriented video images.

The video processing unit 120 has the output interface 124 for providing the output video stream to, for example, the presentation device.

In an example, in the vertical mode, the operation of the video processing module 130 comprises rotating the video images of the received video stream if, for example, the received video images are the horizontally oriented images. In an example, in the horizontal mode, the operation of the video processing module 130 comprises rotating the video images of the received video stream if, for example, the received video images are the vertically oriented images. In an example, the operation of the video processing module 130 may comprise the direct forwarding of the video images of the received video stream to the output video stream if the video images of the received video stream have an orientation that corresponds to the mode in which the video processing module 130 operates. In an example, the operation of the video processing module 130 may comprise cropping of the video images of the received video stream if the video images of the received video stream have a square shape. The cropping results, in dependence of the mode in which the video processing module 130 operates, in the vertically oriented output images or the horizontally oriented output images. In an example, the operation of the video processing module 130 may comprise cropping of the video images of the received video stream if cropped images provide a better view of the child to be monitored in comparison to the video images of the received video stream. It is to be noted that the video images as recorded have a specific aspect ratio (which is a ratio between the width and the height of the images as expressed in a number of pixels). In an embodiment, the aspect ratio of the output images is equal to the specific aspect ratio or is equal to the inverse of the specific aspect ratio (for example, when the video images are rotated before being provided as output images). However, it is not strictly necessary that the aspect ratio of the output images is equal to the aspect ratio of the video images or to the inverse of the aspect ratio of the video images. It may be possible that the display of the presentation device has a different aspect ratio and that, as will be discussed later, while obtaining a crop of the video images or while scaling the output images, the output images of the different aspect ratio are generated. In the context of this document, it is only relevant that the generated output images are the horizontally oriented images or the vertically oriented images in accordance with the mode signal.

Optionally, the above discussed video processing module 130 is also able to scale the horizontally oriented output images or the vertically oriented output images to a predefined required size of the output images. For example, the video images of the received video stream have a first resolution and the output images must have a second resolution that is smaller than the first resolution because of, for example, the resolution of the display of the presentation device - then the video processing module 130 may scale the horizontally oriented output images or the vertically oriented output images downwards to the smaller output images. It may also be that the images must be scaled up if the resolution of the display of the presentation device is larger than the first resolution. This may be the case if the presentation device is, for example, a laptop computer or a tablet computer. Solutions for scaling images are well known, for examples, such scaling techniques may be based on a linear interpolation, a cubic interpolation or a Lanczos interpolation. Scaling is performed according to a scaling factor. The scaling factor is a ratio between a first number and a second number. The first number is the number of pixels in the image to be scaled (crop of video image or video image itself) that must be mapped onto the second number of pixels in the output image. In general the scaling factor is equal in the x dimension and y dimension in particular when the images have the same aspect ratio, however, it may be possible that the video images and/or the crop have slightly deviating aspects ratios and then the x dimension and y dimension scaling factors may slightly deviate from each other, for example, the x dimension and y dimension scaling factors may deviate within a 20% deviation margin from each other. Characteristics and effects of the above discussed features do also apply to the same features of the subsequently discussed embodiments. Hereinafter several additional or alternative features of embodiments of the child monitoring (sub-) systems are discussed - it is to be noted that, in so far appropriate, several of these additional or alternative features may be combined with the above discussed features of the child monitoring sub-system 100.

Fig. 2 schematically shows another embodiment of a child monitoring subsystem 200. The child monitoring sub-system 200 of Fig. 2 is similar to the child monitoring sub-system of Fig. 1. A difference is that a video processing unit 220 also comprises a detection module 240. In use, the detection module 240 generates the mode signal 132. The detection module 240 is also operatively coupled to the input interface 122 for receiving the video stream. In use, the detection module 240 detects in the video images of the received video stream, whether the horizontally oriented output images or the vertically oriented output images provide a better view of the child to be monitored. The detection module 240 generates the mode signal 132 in dependence of this detection.

Optionally, the detection module 240 is capable of detecting in the video images at least one of the subsequent characteristics: a relative position of the child within the video images, a relative orientation of a body of the child with respect to the orientation of the video images, a relative position of one or more elements of a bed in which the child to be monitored lies, a relative orientation of one or more elements of the bed in which the child to be monitored lies. Also, combinations of these characteristics may be determined. The characteristics may be translated to the mode signal on the basis of, for example, specific rules or tables indicating which orientation of the output images is most suitable for presenting the child to be monitored on the presentation device. For example, when the relative orientation of the child to be monitored is determined as "East- West" or "Left-Right", the rules or the tables may define that the horizontally oriented output image is most suitable.

The detection of these characteristics may be based on image recognition technologies. For example, a face of the child to be monitored may be recognized in the video images, the body of the child to be monitored may be recognized in the video images, the bed may be recognized in the video images, or relatively simple elements of the bed, like two or more top-bars or two or more side-bars of the bed, may be recognized in the video images. The detection unit 240 is configured to translate the recognized elements towards the above discussed characteristics. For example, when the top-bars of the bed in the video images have a direction from a bottom of the video images towards a top of the video images, the relative orientation of the bed with respect to the video images may be characterized as 0°, 180 °, North-South. For example, when the top-bars of the bed in the video images have a direction from the left of the video images towards the right of the video images, the relative orientation of the bed with respect to the video images may be characterized as 90°, 270 °, East- West. When the detection unit 240 tries to determine the relative direction of the body of the child in the video images, it is not necessary to recognize the whole body of the child in the video images - for example, when the face is recognized, information may be deducted from the position and the orientation of the face such that, the location and/or the orientation of the body of the child is obtained.

In this context, "bed in which the child to be monitored lies" must be interpreted broadly. The bed may be a crib, a cot or an infant bed. But the bed may also be a bed of the child that is older than an infant, for example, older than 2 years, but must still be monitored. Furthermore, the system may also be used to monitor, for example, handicapped people, elderly people or Alzheimer's patients.

Fig. 3 schematically shows a further embodiment of a child monitoring sub- system 300. The child monitoring sub-system 300 is similar to the child monitoring subsystem 100 of Fig. 1. In the example of Fig. 3, the mode signal 132 is obtained from a mode selection input module 345. The mode selection input module 345 allows the user to provide a preference with respect to the horizontally oriented output images or the vertically oriented output images. The module selection input module 345 translates the received preference to the mode signal 132. The mode selection input module 345 may be a module comprises, for example, switches which allow the user to select one of the orientations. The mode selection input module 345 may also be a Graphical User Interface (GUI) generated by a computer program. The GUI is presented on, for example, a touch screen of the presentation device and the combination of the GUI and the touch screen allows the user to select a preference for the vertically oriented image or the horizontally oriented image. The mode selection input module 345 may be integrated in a parent unit (which comprises the presentation device) or may be integrated in a child unit (which comprises the camera 110).

Fig. 4 schematically shows another embodiment of a child monitoring subsystem 400. Child monitoring sub-system 400 is similar to the child monitoring sub-system 200. A difference is that a video processing unit 420 comprises a video processing module 430 that is also capable of creating crops of the video images of the received video stream. The crops are provided as the output images of the output video stream. Crops are cut-outs of the video images, thus, comprise fewer pixels than the video images. In the vertical mode, the height of the crops is larger than the width of the crops. In the horizontal mode, the width of the crops is larger than the height of the crops. The pixel size / resolution of the crops may be adapted to the capabilities of the presentation device - for example, the pixel size or the resolution of the crops is equal to the resolution of the presentation device. When the video processing module 420 is capable of cropping the video images, the output image may even better show the child to be monitored because it enables that in the output images a larger area of the image shows the child to be monitored. It is to be noted that the previously discussed scaling capability of the video processing module 430 may also be used to scale the crops to the predefined required size of the output images.

The video processing unit 420 may also comprise a detection unit 440 that is similar to the detection unit 240 of Fig. 2 and which has also another capability. In use, the detection unit 400 may detect in which region of the images the child is present. This information may be provided as a region signal 442 to the video processing module 430 which uses the region signal to determine which crop of the video images must be made. In an embodiment, the crop at least comprises the indicated region in the region signal 442. In an embodiment, the crop envelopes the indicated region in the region signal 442.

It is to be noted that the previously discussed elements of the video processing units 120, 220, 420 may be implemented in dedicated hardware as separate hardware elements or as a single piece of dedicated hardware. The previously discussed elements of the video processing units 120, 220, 420 may also be implemented as a general purpose processor that is programmed with a computer program such that the general purpose processor performs the tasks of elements of the above discussed video processing units 120, 220, 420.

Fig. 5 schematically shows an embodiment of a child monitoring system 500 comprising an embodiment of a child monitoring sub-system 502 and a presentation device 550. The child monitoring sub-system 502 may be one of the embodiments of the previously discussed child monitoring sub-systems 100, 200, 300 or 400. In Fig. 5, the reference numbers of the child monitoring sub-system 100 of Fig. 1 are used. The presentation device 550 comprises a display 554 on which the output video stream may be presented and comprises a video stream input 552. The video stream input 552 is operatively coupled to the output interface 124 of the video processing unit 120 of the child monitoring sub-system 502. As such, in use, the video stream input 552 receives the output video stream generated by the video processing unit 120. Optionally, the presentation device 550 may be configured to present the output images of the received output video stream as large as possible on the display 554. Optionally, a resolution of the camera 110 is a first resolution and a resolution of the display 554 is a second resolution. Optionally, the second resolution is smaller than the first resolution. When the second resolution is smaller than the first resolution, a horizontal crop or a vertical crop of the video images may be made, as recorded by the camera 110, such that the child to be monitored is well visible in the crop. If the crop still has the resolution larger than the second resolution, the cropped images are scaled down to the second resolution. For example, today in many child monitoring systems, the resolution that the camera 110 uses is the VGA resolution, which is 640x480 pixels (width x height) and the resolution of the display 554 is 320x240 pixels.

Optionally, the child monitoring system 500 has a video transmitting module 560 and a video receiving module 561. The video transmitting module 560 is configured to wirelessly transmit the video stream and the video receiving module 561 is configured to receive the wirelessly transmitted video stream. For example, the combination of the video transmitting module 560 and the video receiving module 561 is arranged in between the camera 110 and the input interface 122 of the video processing unit 120 for wirelessly transmitting the video stream generated by the camera 110 to the video processing unit 120. In another example, the combination of the video transmitting module 560 and the video receiving module 561 is arranged in between the output interface 124 of the video processing unit 120 and the video stream input 552 of the presentation device 550 for wirelessly transmitting the output video stream generated by video processing unit 120 to the presentation device 550.

Often, the modules and devices of the child monitoring system 500 are distributed over two separate devices: a child unit and a parent unit. The child unit is placed close to the child to be monitored and at least comprises the camera 110 that has to be focused on the child to be monitored. The parent unit is taken by the parents to the place where they reside, for example, in the house, while the child is, for example, sleeping in his bedroom. The parent unit at least comprises the presentation device 550. Depending on the characteristics of the parent unit and/or depending on the wireless transmission technology and/or depending on the resolution of the camera and/or the display 554 of the presentation device 550, the video processing unit 120 may be provided in the parent unit or may be provided in the child unit. For example, when the wireless transmission technology is not able to transmit the video stream with a relative high resolution (which is, for example, generated by a high resolution camera), the video processing unit 120 is most probably integrated in the child unit. If the wireless transmission technology is capable of transmitting the video stream that is generated by the camera and if the parent unit has a lot of processing power (because, for example, the parent unit is a laptop computer, a table computer or a mobile phone with a video processor and/or multi-core processor), the video processing unit 120 may be provided in the parent unit. The video processing unit 120 may be formed by a computer program product that comprises instructions which cause a processor of the parent unit to perform the functions of the video processing unit 120.

Figs. 6a and 6b schematically show embodiments of video images 600, 650 of a video stream recorded by a camera and examples of output images and/or crops of the video images 600, 650.

In Fig. 6a, a schematic example is provided of the video image 600 generated by the camera that is placed at a foot of an infant bed 610. The video image 600 shows a portion of the infant bed 610 and a baby 620.

In an example, the video image 600 may have a VGA resolution and the display of the presentation device may have a QVGA resolution. When the video processing module operates in the horizontal mode, the whole video image 600 is selected as the output image for the output video stream and the whole video image 600 is scaled down to the QVGA resolution. When the video processing module operates in the vertical mode, for example, a vertical crop 640 centered in the middle of the video image 600 is selected for the output image of the output video stream. In this example, no specific detection unit is used. The mode selection may be based on user input received from a mode selection input module. It is to be noted that VGA and QVGA have the same aspect ratio. Image with the aspect ratios of these standards are experienced by users as convenient sizes to monitor a child.

Embodiments of the invention are not limited to images with the aspect ratios of these standards. When the images have the same aspect ratio, the scaling can be performed with an x-dimension scaling factor that is equal to a y-dimension scaling factor. According to embodiments, the video images recorded by the camera and/or the output video images presented on the presentation device may have the resolution defined in a HD video standard (like, HD720 or HD1080). Other video standards may be used in the above discussed embodiments as well.

In another example, the detection unit (of which embodiments have been discussed above) may recognize the baby 620 in the video image 600. The detection unit may generate a region signal that indicates a region close to the center of the video image 600 as it comprises most of the information that is relevant for the child monitoring. This detection unit may also indicate that a horizontally oriented output image is preferred when the output image is taken from a region in the center of the video image 600. Subsequently, the video processing module 600 may crop the video image 600 towards the horizontally oriented crop 630. If necessary the crop 630 may be scaled to a required resolution of the output images of the output video stream.

In another example, the detection unit (of which embodiments have been discussed above) may recognize the top-side bars 612, 614 of the infant bed 610 in the video image 600. Because the top-side bars 612, 614 have an orientation from a bottom of the image towards a top of the image, the detection unit may indicate in the mode signal that the video processing module has to operate in the vertical mode. In such a situation, the video processing module may select crop 640 for the output images and, when appropriate, the crop 640 is scaled to the required resolution. Optionally, the detection unit also provides a regional signal to the video processing module and the regional signal may indicate a region that envelopes the infant bed 610. This information may also result in the fact that crop 640 of the video image 600 is selected for the output image.

The video image 650 of Fig. 6b comprises a vertically oriented image recorded by the camera of one the above discussed embodiments of the child monitoring sub-systems 100, 200, 300, 400, 502 of Fig. 1 to Fig. 5. This camera is located at a right hand side of an infant bed in which a child lies. Consequently, the video image 650 shows a side of the infant bed 660 and the child 670 may be seen through the bars of the infant bed 660.

In an example, the detection unit (of which embodiments have been discussed above) may recognize the child 670 in the video image 650. The detection unit may detect that the direction of the body of the child 670 is from left to right. Consequently, the detection unit may generate the mode signal indicating a horizontal mode. The detection unit may also generate the regional signal that indicates a region in which the baby is present in the video image 650, and, thus, the region that comprises most of the information that is relevant for the child monitoring. Subsequently, the video processing module may crop the video image 600 towards the horizontally oriented crop 680. If necessary, the crop 680 may be scaled by the video processing module to a required resolution of the output images of the output video stream.

In another example, the detection unit detects the characteristics of the infant bed 660, for example, a bar, a corner bar and a top bar. Based on this information, the detection unit is able to detect that the infant bed 660 is presented in a horizontal direction in the video image 650 and, as such, the detection unit may generate a mode signal indicating the horizontal mode. The detection unit may also indicate a region of the video image 650 in which most of the infant bed is present. The video processing unit receiving the mode signal and the regional signal may select horizontally oriented crop 690 for the output images. If necessary, the crop 690 may be scaled by the video processing module to the required resolution of the output images of the output video stream.

In another example, the detection unit is not able to indicate the regional signal and only provides the mode signal indicating the horizontal mode because it is detected that the child 670 or the infant bed 660 is oriented horizontally in the video image 650. The video processing module receiving this mode signal may create a horizontal crop 695 from the video image 650 for the output images of the output video stream.

Fig. 7 schematically shows a method 700 of video processing a video stream of a camera of a child monitoring system to generate an output video stream for a

presentation device of a child monitoring system. The method comprises the stages of: i) receiving 702, a video stream from the camera, the video stream comprises a series of video images of a child to be monitored, ii) receiving 704, a mode signal, iii) generating 706, an output video stream from the received video stream, the output video stream comprises a series of output images, the generation being performed in a vertical mode or in a horizontal mode in dependence on the received mode signal, in the vertical mode, vertically oriented output images are generated, in the horizontal mode, horizontally oriented output images are generated, and iv) providing 708 the output video stream to the presentation device.

Although the stages of the method 700 are presented in a linear order, several tasks of the different stages may be executed in parallel or in another order. For example, the mode signal may be received before or at the same time as the input video stream is received. In practical embodiments, the stages of the method 700 are executed at real-time, which means that the processing is done immediately when the video image is received and that only a short processing time is required. For example, if one video image of the video stream generated by the camera is received, the output image is generated on the basis of this received video image and the output image is immediately provided at the output as part of the output video stream. A very short time later, the next video image is received and processed towards the output image.

Fig. 8 schematically shows a data carrier 810 on which a computer program 820 is stored. The above discussed method 700 of video processing may be executed using software or, in other words, by using the computer program 820, which comprises instructions for causing a processor system to perform the method 700. The computer program 820 may also only include those steps taken by a particular sub-entity of the above discussed child monitoring system or the child monitoring sub-system. The computer program 820 may be stored in a suitable storage medium, such as a hard disk, a floppy, a memory, or a CD or DVD data disk, such as, for example, the data carrier 810, etc. The software or the computer program 820 may be sent as a signal along a wire, or wireless, or using a data network, e.g., the Internet. The software or the computer program 820 may be made available for download and/or for remote usage on a server.

In summary, this application provides, a child monitoring sub-system and a method of video processing a video stream of a camera of a child monitoring system. The child monitoring sub-system comprises a camera and a video processing unit. The camera provides a video stream comprising a series of video images. The video processing unit comprises an input interface, a detection module, a video processing module and an output interface. The input interface receives the video stream. The detection module detects relative orientation of the child with respect to the video images. The video processing module generates from the received video stream an output video stream comprising a series of output images. The video processing module operates in a vertical mode or in a horizontal mode depending on a mode signal. In the vertical mode, the processing module generates vertically oriented output images. In the horizontal mode, the processing module generates horizontally oriented output images. The output interface provides the output video stream to a presentation device.

Although the invention has been mainly explained by embodiments of child monitoring, the invention is also suitable for any other form of monitoring, such as in a security camera application.

It is to be noted that the invention may be implemented in hardware and/or software, using programmable components. A method for implementing the invention has the steps corresponding to the functions defined for the system as described with reference to Fig.

1.

It will be appreciated that the above description for clarity has described embodiments of the invention with reference to different functional units and processors. However, it will be apparent that any suitable distribution of functionality between different functional units or processors may be used without deviating from the invention. For example, functionality illustrated to be performed by separate units, processors or controllers may be performed by the same processor or controllers. Hence, references to specific functional units are only to be seen as references to suitable means for providing the described functionality rather than indicative of a strict logical or physical structure or organization. The invention can be implemented in any suitable form including hardware, software, firmware or any combination of these.

It is noted, that in this document the word 'comprising' does not exclude the presence of other elements or steps than those listed and the word 'a' or 'an' preceding an element does not exclude the presence of a plurality of such elements, that any reference signs do not limit the scope of the claims, that the invention may be implemented by means of both hardware and software, and that several 'means' or 'units' may be represented by the same item of hardware or software, and a processor may fulfill the function of one or more units, possibly in cooperation with hardware elements. Further, the invention is not limited to the embodiments, and the invention lies in each and every novel feature or combination of features described above or recited in mutually different dependent claims.

Examples of a child monitoring sub-system and a method of video processing a video stream of a camera are defined in the following numbered clauses:

1. A child monitoring sub-system (100, 200, 300, 400, 502) for a child

monitoring system (500), the child monitoring sub-system (100, 200, 300, 400, 502) is for generating an output video stream, the child monitoring sub-system (100, 200, 300, 400, 502) comprising:

- a camera (110) configured to provide a video stream of a child to be monitored, the video stream comprising a series of video images, and

a video processing unit (120, 420) comprising:

i) an input interface (122) for receiving the video stream,

ii) a video processing module (130, 430) being configured to

- generate from the received video stream an output video stream comprising a series of output images,

- operate in a vertical mode or in a horizontal mode depending on a mode signal (132),

- generate in the vertical mode vertically oriented output images,

- generate in the horizontal mode horizontally oriented output images,

iii) an output interface (124) for providing the output video stream to a presentation device of the child monitoring system.

2. A child monitoring sub-system (100, 200, 300, 400, 502) according to clause 1, wherein the video processing unit (120, 420) comprises a detection module (240, 440) for generating the mode signal (132), the detection module (240, 440) being configured to also receive the received video stream and to detect in the video images whether the horizontally oriented output images or the vertically oriented output images provide a better view of the child to be monitored, and the detection module (240, 440) is configured to generate the mode signal depending on the detection.

3. A child monitoring sub-system (100, 200, 300, 400, 502) according to clause 2, wherein the detection module (240, 440) being configured to detect in the video images at least one of a relative position of the child, a relative orientation of a body of the child, relative positions of elements of a bed in which the child to be monitored lies, and a relative orientation of the elements of the bed in which the child to be monitored lies.

4. A child monitoring sub-system (100, 200, 300, 400, 502) according to clause 1 further comprising a mode selection input module (345) for receiving from a user a preference with respect to the horizontally oriented output images or the vertically oriented output images and wherein the mode selection input module generates the mode signal.

5. A child monitoring sub-system according to any one of the previous clauses, wherein the video processing module (130, 430) is configured to create a crop of the video images, in accordance with the mode signal, that are vertically oriented or horizontally oriented and configured to provide the crop of the video images as the output images.

6. A child monitoring sub-system (100, 200, 300, 400, 502) according to any one of the clauses 2 or 3 in combination with clause 5, wherein

- the detection module (240, 440) is configured to detect in which region of the video images the child is present, and

the video processing module (130, 430) is configured to select an area of the video images for the crop of the video images on basis of the detected region. 7. A child monitoring sub-system (100, 200, 300, 400, 502) according to any one of the previous clauses, wherein the video processing module (130, 430) is configured to scale the horizontally oriented output images or the vertically oriented output images to a required size of the output images. 8. A child monitoring sub-system (100, 200, 300, 400, 502) according to any one of the previous clauses, wherein the video images have a first resolution of a first number of pixels, and the output images have a second resolution of a second number of pixels, the second number of pixels being smaller than the first number of pixels.

9. A child monitoring system (500) comprising the child monitoring sub-system (100, 200, 300, 400, 502) according to any one of the preceding clauses and comprising a presentation device (550), the presentation device (550) comprising a display (554) for displaying the output video stream and comprising a video stream input (552) for receiving the output video stream of the video processing unit.

10. A child monitoring system (500) according to the combination of clause 8 and clause 9, wherein the camera (110) has the first resolution, and the display (554) of the presentation device has the second resolution.

11. A child monitoring system (500) according to any one of the clauses 9 or 10, wherein the child monitoring system (500) comprises a video transmitting module (560) and a video receiving module (561) for providing a wireless video connection between the two respective modules, wherein the wireless video connection is provided in between the camera (HO) and the video processing unit (120, 420), or the wireless video connection is provided in between the video processing unit (120, 420) and the presentation device (550).

12. A method (700) of video processing a video stream of a camera of a child monitoring system to generate an output video stream for a presentation device of the child monitoring system, the method comprises:

- receiving (702) a video stream from the camera, the video stream comprising a series of video images of a child to be monitored,

- receiving (704) a mode signal,

- generating (706) an output video stream from the received video stream, the output video stream comprising a series of output images, the generation being performed in a vertical mode or in a horizontal mode depending on the received mode signal, in the vertical mode, vertically oriented output images, in the horizontal mode, horizontally oriented output images,

- providing (708) the output video stream to the presentation device. 13. A computer program product for video processing video images of a child monitoring system to generate an output video stream for a presentation device of the child monitoring system, which program is operative to cause a processor to perform the method according clause 12.

Claims

CLAIMS:

1. A child monitoring sub-system (100, 200, 300, 400, 502) for a child monitoring system (500), the child monitoring sub-system (100, 200, 300, 400, 502) is for generating an output video stream, the child monitoring sub-system (100, 200, 300, 400, 502) comprising:

a camera (110) configured to provide a video stream of a child to be monitored, the video stream comprising a series of video images, and

a video processing unit (120, 420) comprising:

i) an input interface (122) for receiving the video stream,

ii) a detection module (240, 440) for detecting a relative orientation of the child with respect to the video images, and for generating a corresponding mode signal for indicating a vertical mode or a horizontal mode,

iii) a video processing module (130, 430) being configured to

- operate in the vertical mode or in the horizontal mode depending on the mode signal (132),

- generate in the vertical mode vertically oriented output images,

- generate in the horizontal mode horizontally oriented output images, iv) an output interface (124) for providing the output video stream to a presentation device of the child monitoring system.

2. A child monitoring sub-system (100, 200, 300, 400, 502) according to claim 1, the detection module (240, 440) being configured to also receive the received video stream and to detect in the video images whether the horizontally oriented output images or the vertically oriented output images provide a better view of the child to be monitored, and the detection module (240, 440) is configured to generate the mode signal depending on the detection.

3. A child monitoring sub-system (100, 200, 300, 400, 502) according to claim 2, wherein the detection module (240, 440) being configured to detect in the video images at least one of a relative position of the child, a relative orientation of a body of the child, relative positions of elements of a bed in which the child to be monitored lies, and a relative orientation of the elements of the bed in which the child to be monitored lies.

4. A child monitoring sub-system (100, 200, 300, 400, 502) according to any of the preceding claims, wherein the output images are mostly filled with pixels of the child.

5. A child monitoring sub-system (100, 200, 300, 400, 502) according to any of the preceding claims, wherein the video processing module (130, 430) is configured to operate in the vertical mode if the output images comprise more pixels of the child in the vertical direction than in the horizontal direction or in the horizontal direction if the output images comprise more pixels of the child in the horizontal direction than in the vertical direction.

6. A child monitoring sub-system (100, 200, 300, 400, 502) according to claim 1 further comprising a mode selection input module (345) for receiving from a user a preference with respect to the horizontally oriented output images or the vertically oriented output images and wherein the mode selection input module generates the mode signal.

7. A child monitoring sub-system according to any one of the previous claims, wherein the video processing module (130, 430) is configured to create a crop of the video images, in accordance with the mode signal, that are vertically oriented or horizontally oriented and configured to provide the crop of the video images as the output images.

8. A child monitoring sub-system (100, 200, 300, 400, 502) according to any one of the claims 2 or 3 in combination with claim 7, wherein

the detection module (240, 440) is configured to detect in which region of the video images the child is present, and

the video processing module (130, 430) is configured to select an area of the video images for the crop of the video images on basis of the detected region.

9. A child monitoring sub-system (100, 200, 300, 400, 502) according to any one of the previous claims, wherein the video processing module (130, 430) is configured to scale the horizontally oriented output images or the vertically oriented output images to a required size of the output images.

10. A child monitoring sub-system (100, 200, 300, 400, 502) according to any one of the previous claims, wherein the video images have a first resolution of a first number of pixels, and the output images have a second resolution of a second number of pixels, the second number of pixels being smaller than the first number of pixels.

11. A child monitoring system (500) comprising the child monitoring sub-system (100, 200, 300, 400, 502) according to any one of the preceding claims and comprising a presentation device (550), the presentation device (550) comprising a display (554) for displaying the output video stream and comprising a video stream input (552) for receiving the output video stream of the video processing unit.

12. A child monitoring system (500) according to the combination of claim 10 and claim 11, wherein the camera (110) has the first resolution, and the display (554) of the presentation device has the second resolution.

13. A child monitoring system (500) according to any one of the claims 11 or 12, wherein the child monitoring system (500) comprises a video transmitting module (560) and a video receiving module (561) for providing a wireless video connection between the two respective modules, wherein the wireless video connection is provided in between the camera (HO) and the video processing unit (120, 420), or the wireless video connection is provided in between the video processing unit (120, 420) and the presentation device (550).

14. A method (700) of video processing a video stream of a camera of a child monitoring system to generate an output video stream for a presentation device of the child monitoring system, the method comprises:

receiving (702) a video stream from the camera, the video stream comprising a series of video images of a child to be monitored,

detecting a relative orientation of the child with respect to the video images, generating a corresponding mode signal for indicating a vertical mode or a horizontal mode,

receiving (704) the mode signal,

generating (706) an output video stream from the received video stream, the output video stream comprising a series of output images, the generation being performed in the vertical mode or in the horizontal mode depending on the received mode signal, in the vertical mode, vertically oriented output images, in the horizontal mode, horizontally oriented output images,

providing (708) the output video stream to the presentation device.

15. A computer program product for video processing video images of a child monitoring system to generate an output video stream for a presentation device of the child monitoring system, which program is operative to cause a processor to perform the method claimed in claim 14.