JP4735649B2 - Image projection device - Google Patents

Description

The present invention relates to a captured image projection equipment.

2. Description of the Related Art In recent years, as a photographed image projection apparatus, a user photographs a document placed on a document table with a camera, stores image data of the document photographed with the camera, performs image processing, and uses a projector to scan the document on the screen. There is one that enlarges and projects an image (see, for example, Patent Document 1).
JP 2002-354331 A (page 2-3, FIG. 1)

However, in such a conventional photographed image projection apparatus, since it takes time to process the image of the document on the screen, the frame frequency of the image is lowered.
The present invention has been made in view of such conventional problems, and aims to provide the acquired captured image projection equipment which can shorten the processing time to project an image by photographing To do.

In order to achieve this object, a captured image projection apparatus according to the first aspect of the present invention provides:
In a captured image projection device that projects an image of a captured subject on a screen,
A camera for photographing the subject and outputting image data of the photographed subject;
An image processing unit that performs image processing on image data output by the camera;
A projection unit that projects an image based on the image data image-processed by the image processing unit;
Movement determination means for determining whether or not there is movement in an image captured by the camera;
When the motion determination means determines that the image has motion, the camera, the image processing unit, and the projection unit are controlled so that images with low resolution are continuously captured by the camera and projected by the projection unit. When the motion determining means determines that there is no motion in the image, the camera, the image processing unit, and the projection unit are controlled so that a high-resolution image is temporarily captured by the camera and projected by the projection unit. And a controller that controls the projection unit to continuously project a high-resolution image until the low-resolution image is continuously captured by the camera and the motion determination unit determines that the image has motion. , With.

The controller is
When the frame frequency of an image photographed by the camera is set in advance and the motion discriminating means determines that the image has a motion, the frame frequency of the image photographed by the camera is increased. When the image processing unit and the projection unit are controlled and the motion determination unit determines that there is no motion in the image, the frame frequency of the image captured by the camera is set to the lower one, and the data amount of the image data is set. The camera, the image processing unit, and the projection unit may be controlled so as to increase the resolution and increase the resolution.

  The determination means determines whether or not there is a motion in an image captured by the camera, and determines whether the image is a higher one of preset frame frequencies and has a resolution corresponding to the frame frequency. It may be based on this.

The determination means includes
An image change amount of an image captured by the camera is obtained. If the image change amount is less than a preset threshold value, it is determined that there is no movement in the image captured by the camera, and the image change amount is determined in advance. It may be determined that there is a motion in the image as long as it is greater than or equal to a set threshold value.

  The determination means stores the previous value of the image data captured by the camera, and obtains the sum of the difference between the previous value of the stored image data and the current value of the newly captured image data, An image change amount may be obtained.

  According to the present invention, it is possible to shorten the processing time until an image acquired by photographing is projected.

Hereinafter, a captured image projection apparatus according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows the configuration of a captured image projection apparatus according to the embodiment.
The captured image projection apparatus includes a document camera 1, a computer 2, and a projector 3.

  The document camera 1 is a camera system for photographing a document 4 to be projected, and includes a digital camera 11, a column 12, and a pedestal 13. The digital camera 11 is for photographing the document 4. The column 12 is for attaching the digital camera 11. The pedestal 13 is for supporting the column 12.

The digital camera 11 of the document camera 1 includes an optical lens device 101 and an image sensor 102 as shown in FIG.
The optical lens device 101 is composed of a lens for condensing image light.

  The image sensor 102 is for capturing an image formed by the optical lens device 101 condensing light as digitized image data, and is configured by a CCD or the like.

  The document camera 1 and the computer 2 are connected via a cable 14 such as a USB, and the document camera 1 outputs image data of the document 4 photographed by the digital camera 11 to the computer 2 via the cable 12.

  The computer 2 performs image processing on the image data sent from the document camera 1. The computer 2 generates image data of the document 4 photographed from the front by performing image processing even when the document 4 is inclined or rotated with respect to the photographing surface of the digital camera 11. .

  As shown in FIG. 2, the computer 2 includes a memory 103, a display device 104, an image processing device 105, a key operation unit 106, a program code storage device 107, and a CPU 108.

  The memory 103 is for temporarily storing an image from the image sensor 102, an image to be sent to the display device 105, and the like. The memory 103 is also used as a work memory for the CPU 108.

The display device 104 is for sending an image to the projector 3.
The image processing apparatus 105 is for performing image processing such as image distortion correction and image effect on the image data temporarily stored in the memory 103.

  The key operation unit 106 includes switches and keys for controlling the document projection function. The key operation unit 106 outputs operation information on operation of switches and keys by the user to the CPU 108.

The program code storage device 107 is for storing a program executed by the CPU 108, and is configured by a ROM or the like.
The CPU 108 controls each unit described above according to a program stored in the program code storage device 107.
Further, the CPU 108 determines whether or not there is a motion in the image of the document 4 that is a photographing target according to a flowchart described later, and switches the projection mode according to the determination result.

  There are two projection modes: a moving image mode and a still image mode. The moving image mode is a mode that is set when the user intends to place the document 4 or the like that the user wants to project on the pedestal 13, and is a mode that projects the image projected by the digital camera 11 onto the projector 3 as it is.

  In the moving image mode, the CPU 108 controls each unit so that, for example, an image having an image resolution of about VGA (600 × 480 dots) is projected at a speed of 30 fps (frames / second). As described above, the moving image mode is a mode in which real-time characteristics are emphasized although the resolution is low.

  The still image mode is a mode that is set after the user places a document, and is a mode in which a high-resolution image is taken by the digital camera 11 and a high-resolution still image is projected. When the digital camera 11 is a camera with an imaging resolution of 3 million pixels, the cut-out projected image is an XGA (1024 × 768) still image.

  The CPU 108 determines whether or not there is a motion in the image of the document 4 in order to switch the projection mode. In order to make such a determination, the CPU 108 obtains a change amount MD from the previously captured image. The amount of change (MD) is an amount representing how much the image being taken has changed compared to the previous image. There are several ways to calculate this quantity. As an example, the CPU 108 obtains the sum of absolute values of differences between the pixels as the change amount MD from the data of the previously captured image.

That is, assuming that the previous pixel data is Pn-1 (x, y) and the current pixel data is Pn (x, y) 1 ≦ x ≦ 640 1 ≦ x ≦ 480, the amount of change MD is given by expressed.
However, since the amount of calculation is large in order to obtain the total sum of all the pixels, as a method for obtaining the change amount MD, there is a method in which several pixels are extracted and realized.

  In addition, a threshold value Thresh1 and a threshold value Thresh2 are set in advance as threshold values for determining the presence or absence of movement in comparison with the change amount MD. The threshold value Thresh1 is a threshold value for determining whether or not there is a motion, and the CPU 108 determines that there is no motion if the change amount MD is less than the threshold value Thresh1.

  The threshold value Thresh2 is a slight movement that does not require switching to the video mode even if there is a movement, for example, when a shadow moves or a pen is placed in the still image mode. It is a threshold value for determining whether or not.

  If the amount of change MD is less than the threshold value Thresh2, the CPU 108 determines that the movement is slight enough not to switch to the moving image mode. The threshold value Thresh2 is set higher than the threshold value Thresh1 (Thresh1 <Thresh2). The memory 103 stores the threshold value Thresh1 and the threshold value Thresh2 in advance.

  Further, when switching from the moving image mode to the still image mode, the CPU 108 determines that there is no motion in the image, and switches the projection mode to the still image mode after a predetermined time has elapsed. For this reason, after determining that there is no motion in the image, the CPU 108 measures the still time Ptime, and the memory 103 stores a predetermined time HoldTime set in advance for comparison with the still time Ptime.

  The projector 3 irradiates the screen 5 with projection light and forms an image of the document 4. The computer 2 and the projector 3 are connected via a cable such as RBG.

Next, the operation of the captured image projection apparatus according to this embodiment will be described.
When the user turns on the power of the captured image projection apparatus, the CPU 108 of the computer 2 reads out the program code from the program code storage device 107 and executes basic projection processing.

This operation will be described with reference to the flowchart shown in FIG.
First, the CPU 108 initializes camera setting parameters such as the focus, exposure, and white balance of the digital camera 11 of the document camera 1 (S10).

  The CPU 108 initializes the projection mode to the moving image projection mode (step S11). The CPU 108 sets the moving image mode (Motion) in the designated area on the memory 103 in order to initialize the projection mode to the moving image mode. Further, the CPU 108 sets the image data read from the image sensor 102 of the digital camera 11 to be image data by VGA.

  As a result, the scene captured by the digital camera 11 is condensed on the image sensor 102 via the optical lens device 101, and the image sensor 102 generates a digital image with a low resolution for moving image shooting from the collected image. create. Then, the image sensor 102 sends out the created digital image to the memory 103 periodically, for example, at 10 sheets per second.

Next, the CPU 108 resets the stationary time Ptime (S12).
Next, the CPU 108 controls the image sensor 102 and the memory 103 so as to transfer low-resolution image data from the image sensor 102 to the memory 103 (S13). Here, the image data of the image sensor 102 is only transferred to the memory 103, and the display device 104 does not display an image. The reason why the display device 104 does not display an image is that image data to be displayed on the display device 104 is stored in areas indicated by different addresses on the memory 103.

  Next, the CPU 108 obtains the amount of change (MD) from the previously captured image according to Equation 1 (step S14).

The CPU 108 determines whether the projection mode is the moving image projection mode or the still image projection mode (step S15).
In the initial state, the moving image projection mode is set as the projection mode. Therefore, in the initial state, the CPU 108 determines that the moving image mode is selected, and copies the moving image data in the memory 103 to a predetermined area of the memory 103 in order to project the captured moving image (step S16). As a result, the display device 104 reads the captured image data from the memory 103 and outputs RGB signals to the projector 3. The projector 3 projects an image based on this signal.

  The CPU 108 compares the threshold value Thresh1 set in advance with the image change amount MD obtained in S14, and determines whether or not there is a motion based on the comparison result (step S17).

  At this time, if the user still continues the operation such as placing paper, the image change amount MD is equal to or greater than the threshold value Thresh1. In this case, the CPU 108 determines that there is a motion in the image (Yes in step S 17), resets the still time Ptime, reads low-resolution image data, obtains the image change amount MD, and obtains the image memory 103. Writing to the projected image area is performed (steps S12 to S16). As a result, while the user performs an operation, the captured image projection apparatus continues to maintain the moving image mode state, and a low-resolution moving image is projected onto the screen 5.

  After that, when the user finishes setting the paper and the image stops moving, the image change amount MD becomes less than the threshold value. In this case, the CPU 108 determines that there is no motion in the image (No in step S17), and adds 1 to the still time Ptime (step S18).

  Then, the CPU 108 determines whether or not the stationary time Ptime has reached a predetermined time HoldTime (step S19).

  If it is determined that the still time Ptime has not reached the predetermined time HoldTime (No in step S19), the CPU 108 reads low-resolution image data again and determines the image change amount MD until it determines that there is no motion in the image. If there is no movement, 1 is added to the stationary time Ptime (steps S13 to S18). In this case, since the stationary time Ptime is not reset, the stationary time Ptime is counted up by the CPU 108 every time a moving image is read.

  If it is determined that the still time Ptime has reached the predetermined time HoldTime (Yes in step S19), the CPU 108 determines that the user has stopped the image, and sets the projection mode to the still image mode (step S20).

  The CPU 108 controls the image sensor 102 so as to capture a high-resolution still image (step S21). Then, the CPU 108 writes the image data acquired by the image sensor 102 into the memory 103. The CPU 108 writes the image data in the memory 103 and then returns the resolution of the digital camera 11 to the low resolution reading state again.

  The CPU 108 controls the image processing apparatus 105, and the image processing apparatus 105 extracts projection parameters for oblique correction on the read high-resolution still image (step S22).

The image processing apparatus 105 further performs projection correction, which is a cutout of the imaging target and creation of a corrected image on the front image, in accordance with the extracted projection parameters (step S23).
The image processing apparatus 105 performs parameter extraction for image effect processing for converting the created corrected image into a clear and easily identifiable image such as contrast correction (step S24).
The image processing apparatus 105 performs image effect processing on the corrected image using the extracted image effect parameters (step S25).

  The CPU 108 writes the corrected image data in a predetermined area in the memory 103 in the same manner as in the case of the moving image, in order to project the corrected image data subjected to the effect processing. Then, the CPU 108 outputs image data as RGB signals to the projector 3 from the display device 104 (step S26).

  Once in the still image mode, the CPU 108 resets the still time Ptime again, reads a low resolution image, and obtains the image change amount MD (steps S12 to S14).

  Here, when the projection mode is determined to be the still image projection mode (step S15), the CPU 108 compares the obtained image change amount MD with another predetermined threshold value Thresh2 (Thresh1 <Thresh2), and the image has a motion. It is determined whether or not there is (step S30).

  If the image change amount is equal to or greater than the threshold value Thresh2, CPU 108 determines that there is no motion in the image (No in step S30). In this case, the CPU 108 continuously compares the image change amount with the threshold Thresh1 (step S31), and determines whether or not there is a motion in the image (step S31).

  If the image change amount MD is equal to or greater than the threshold value Thresh1, the CPU 108 determines that there is a motion in the image (Yes in step S30), and sets the projection mode to the moving image mode (step S40). Then, the CPU 108 resets the stationary time Ptime (step S12).

  On the other hand, even if the image change amount MD is less than the threshold value Thresh2, if it is equal to or greater than the threshold value Thresh1, the CPU 108 determines that there is a motion in the image (Yes in step S31). In this case, since the image change amount MD is between the threshold value Thresh1 and the threshold value Thresh2, the CPU 108 captures a still image with high resolution again without switching the projection mode to the moving image mode, and the image processing apparatus 105 Image processing of the acquired high-resolution still image data is performed (steps S21 to S26).

  If the image change amount MD is less than the threshold value Thresh2 and less than the threshold value Thresh1, the CPU 108 determines that the still state continues (No in step S31). In this case, the CPU 108 determines whether or not the image adjustment key has been operated based on the operation information output from the key operation unit 106 (step S32).

  If it is determined that the image adjustment key has not been operated (No in step S32), the CPU 108 returns to step S12 and resets the stationary time Ptime.

  If it is determined that the image adjustment key has been operated (Yes in step S32), the CPU 108 adjusts image conversion such as image enlargement or rotation (step S33).

  The CPU 108 determines whether the image conversion is projection correction, rotation correction, or the like, or enlargement / reduction or movement of the image (step S34).

  If it is determined that the image conversion is projection correction, rotation correction, or the like, the CPU 108 performs image effect processing using the image effect parameters extracted from the previous image (step S24), and performs the effect processing of the corrected image. (Step S25). On the other hand, when it is determined that the image conversion is enlargement / reduction or movement of the image, the CPU 108 performs image effect processing without using the image effect parameter extracted from the previous image (step S25).

  In this way, the CPU 108 performs projection control while switching between the moving image projection mode and the still image projection mode. As a result, while the user is performing the operation, the frame frequency priority image is projected, and when the image is stationary, the document 4 to be photographed is cut out and the image effect is projected to project the high resolution image. Is called.

  As described above, according to the present embodiment, images having different resolutions, frame frequencies, and image processes are switched and projected. Therefore, when projecting an image of a document on the screen, the document can be projected with a high-quality image, and when replacing the document, an image giving priority to the frame frequency can be projected to shorten the processing time.

  In addition, since the switching of a plurality of images is automatically performed by detecting the movement of the photographing target, it is possible to avoid the trouble of switching the image projection mode to the user. In addition, when projecting a document, the frame frequency is displayed while the document is replaced, so the operation of replacing the projected image can be performed smoothly and the high quality image is automatically displayed after placing the document. Since it switches to an image, it has excellent visibility.

  In addition, since a partial difference image of the low resolution image is used for the motion of the object, the captured image projection device can be realized with a simple structure.

  In addition, once the still image projection mode is set, the presence / absence of movement of the photographing target is determined based on two threshold values. For example, when there is little movement of placing a shadow or a pen, moving image projection is performed. Since the image is taken again at a high resolution without going through the mode, smooth projection becomes possible.

In carrying out the present invention, various forms are conceivable and the present invention is not limited to the above embodiment.
For example, it is possible to perform image processing that does not require processing time. That is, in step S16 in FIG. 3, the image processing apparatus 105 performs only color adjustment. This processing content is shown in the flowchart of FIG.

The image processing apparatus 105 obtains an average value of hue (U, V) from the moving image to be processed (step S801).
The image processing apparatus 105 performs color adjustment by adjusting the luminance histogram according to the background color using the average value (step S802).

  The image processing apparatus 105 writes the image subjected to this image effect in the memory 103 (step S803). Even when a low-resolution image is projected in this way, simple image processing and image effects can be performed if processing time is not required.

  In the above embodiment, two thresholds are used for comparison with the image change amount MD. However, the threshold value may be three or more, and different image processing may be performed on the image according to the amount of motion of the image.

Further, a program for executing the above-described processing is stored and distributed on a computer-readable recording medium such as a flexible disk, a CD-ROM (Compact Disk Read-Only Memory), a DVD (Digital Versatile Disk), and the like. May be installed in a computer and operated as the above-described means, or the above-described steps may be executed.
The program may be stored in a disk device or the like included in a server device on the Internet, and may be downloaded onto a computer by being superimposed on a carrier wave, for example.

1 is a configuration diagram illustrating an overall configuration of a captured image projection apparatus according to an embodiment of the present invention. It is a block diagram which shows the structure of the document camera and computer shown in FIG. It is a flowchart which shows the content of the basic projection process which the picked-up image projection apparatus shown in FIG. 1 performs. It is a flowchart which shows the application example of the picked-up image projection apparatus shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Document camera, 2 ... Computer, 3 ... Projector, 5 ... Screen, 108 ... CPU

Claims (5)

In a captured image projection device that projects an image of a captured subject on a screen,
A camera for photographing the subject and outputting image data of the photographed subject;
An image processing unit that performs image processing on image data output by the camera;
A projection unit that projects an image based on the image data image-processed by the image processing unit;
Movement determination means for determining whether or not there is movement in an image captured by the camera;
When the motion determination means determines that the image has motion, the camera, the image processing unit, and the projection unit are controlled so that images with low resolution are continuously captured by the camera and projected by the projection unit. When the motion determining means determines that there is no motion in the image, the camera, the image processing unit, and the projection unit are controlled so that a high-resolution image is temporarily captured by the camera and projected by the projection unit. And a controller that controls the projection unit to continuously project a high-resolution image until the low-resolution image is continuously captured by the camera and the motion determination unit determines that the image has motion. With
A photographed image projection apparatus characterized by the above. The controller is
When the frame frequency of an image photographed by the camera is set in advance and the motion discriminating means determines that the image has a motion, the frame frequency of the image photographed by the camera is increased. When the image processing unit and the projection unit are controlled and the motion determination unit determines that there is no motion in the image, the frame frequency of the image captured by the camera is set to the lower one to reduce the data amount of the image data. Controlling the camera, the image processing unit, and the projection unit so as to increase the resolution further.
The photographed image projection apparatus according to claim 1. The determination means determines whether or not there is a motion in an image captured by the camera, and determines whether the image is a higher one of preset frame frequencies and has a resolution corresponding to the frame frequency. Based on the
The captured image projection apparatus according to claim 2, wherein: The determination means includes
An image change amount of an image captured by the camera is obtained. If the image change amount is less than a preset threshold value, it is determined that there is no movement in the image captured by the camera, and the image change amount is determined in advance. If it is greater than or equal to the set threshold, it is determined that there is movement in the image.
The photographed image projector according to claim 2 or 3, The determination means stores the previous value of the image data captured by the camera, and obtains the sum of the difference between the previous value of the stored image data and the current value of the newly captured image data, Find the amount of image change,
The photographed image projection apparatus according to claim 4, wherein: