JP2007295049A - Projector, and video image projection method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure good projection state of a projector free from strange feeling constantly even when trapezoidal distortion correction is performed. <P>SOLUTION: In a projector equipped with a function for correcting trapezoidal distortion, a video image frame 200 is synthesized at the outer circumferential edge of a video image 100 accompanied by trapezoidal distortion correction when it is projected. Even when the projection image 100 is dark, boundary between the projection image 100 and a projection region 101 on the periphery thereof is clarified by the video image frame 200 and they are not recognized integrally. As a result, strange feeling caused by existence of trapezoidal distortion can be eliminated in the peripheral projection region 101. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a projector having a trapezoidal distortion correction function, a video projection method, and a program.

2. Description of the Related Art Conventionally, projectors that have a trapezoidal distortion correction (keystone correction) function are generally used in projectors that project and display images and images based on input video signals on an arbitrary screen. This function corrects the projected image on the screen into a regular shape (rectangle) by distorting the shape of the input image on the various projection devices in the direction opposite to the direction of the distortion generated in the projected image on the screen. It is. Further, as a correction method, there are a method in which a user specifies a distortion direction (vertical and horizontal directions) and a correction amount by a predetermined key operation, and a method of automatically acquiring a distortion direction and a correction amount (for example, refer to Patent Document 1 below). .
JP 2004-208089 A

  However, the above-mentioned trapezoidal distortion correction in the projector does not correct the shape of the projection area of the projection light projected on the screen, but a normal shape (rectangular shape) having a size that fits within the projection light projection range. However, there are the following problems.

  That is, when a corrected image is projected on the screen, a projection area of projection light (hereinafter referred to as a peripheral projection area) in a state where trapezoidal distortion is present exists outside the projected image. In addition, the peripheral projection area is assigned the lowest luminance level as a gradation, that is, black (transparent). However, since it is difficult to express the peripheral projection area as completely black (transparent), the projection image 100 that is in the corrected state is displayed on the screen during the projection with the trapezoidal distortion correction. The existing peripheral projection area 101 is in a recognizable state (see FIG. 4B).

  Therefore, in the case where the projected image is a dark scene, the boundary between the projected image 100 and the peripheral projection region 101 is ambiguous on the screen, so that both are easily recognized as a single unit. The trapezoidal distortion existing in 101 causes the viewer to feel uncomfortable. In particular, when projecting in a dark environment where, for example, natural light is blocked and illumination is not used, the above-described problem is likely to occur because the outer shape of the peripheral projection area 101 is easily recognized.

  The present invention has been made in view of such conventional problems, and provides a projector, a video projection method, and a program that can always ensure a good projection state without a sense of incongruity even when keystone distortion correction is performed. The purpose is to provide.

  In order to solve the above-mentioned problem, in the invention of claim 1, in a projector having a correction function for correcting trapezoidal distortion generated in the video when the video based on the input image signal is projected onto an arbitrary projection target, When projecting an image accompanied by correction by the correction function, frame synthesizing means for synthesizing an image frame on the outer periphery of the image is provided.

  In such a configuration, when the trapezoidal distortion is corrected, a video frame is synthesized with an image projected on an arbitrary projection target, that is, an outer periphery of the projection video, so that the projection screen (display screen) The boundary between the projected image in (above) and the peripheral projection area existing outside the projected image becomes clear. Therefore, even when the projected image is dark, the projected image and the peripheral projection area are not recognized integrally, and the sense of incongruity caused by the presence of trapezoidal distortion in the peripheral projection area is eliminated. Can do.

  According to a second aspect of the present invention, there is provided a detecting means for detecting the brightness of the video, and the frame synthesizing means is configured such that the brightness of the video detected by the detecting means is below a predetermined reference. The video frame is synthesized with the outer periphery of the video.

  According to a third aspect of the invention, there is provided second detecting means for detecting ambient brightness in a projection environment, and the frame synthesizing means is the ambient brightness detected by the second detecting means. When the length is equal to or less than a predetermined reference, a video frame is synthesized with the outer periphery of the video.

  According to a fourth aspect of the invention, there is provided setting means for setting the attribute of the video frame based on the image signal, and the frame synthesizing means is set by the setting means at an outer periphery of the recorded video. A video frame having attributes is synthesized.

  According to a fifth aspect of the present invention, the frame synthesizing unit synthesizes an image frame with an outer peripheral edge of the image corrected by the correction function.

  According to a sixth aspect of the present invention, the frame synthesizing unit synthesizes a video frame with an outer peripheral edge of a video based on an input image signal before correction by the correction function.

  According to a seventh aspect of the present invention, there is provided an image projection method for a projector having a correction function for correcting a trapezoidal distortion generated in an image based on an input image signal when the image is projected onto an arbitrary projection target. The video projecting method of synthesizing the video frame with the outer peripheral edge of the video when the video with the correction by the correction function is projected.

  According to this method, when the trapezoidal distortion is corrected, an image frame is synthesized with an image projected on an arbitrary projection target, that is, an outer periphery of the projection image. The boundary between the projected image on the screen and the peripheral projection area existing outside the projected image becomes clear. Therefore, even when the projected image is dark, the projected image and the peripheral projection area are not recognized integrally, and the sense of incongruity caused by the presence of trapezoidal distortion in the peripheral projection area is eliminated. Can do.

  According to another aspect of the invention, the computer includes a computer having a correction function for correcting a trapezoidal distortion generated in the video when the video based on the input image signal is projected onto an arbitrary projection target. A program for executing a process for synthesizing a video frame on the outer periphery of the video when projecting a video with correction by function.

  As described above, according to the present invention, even when the projected image is dark, the projected image and the peripheral projection area are not recognized integrally, and the trapezoidal distortion exists in the peripheral projection area. It was made possible to eliminate the uncomfortable feeling caused by. Therefore, even when performing trapezoidal distortion correction, it is possible to ensure a good projection state without any sense of incongruity.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an outline of the electrical configuration of a projector 1 according to the present invention. The projector 1 has a known manual trapezoidal distortion correction function and an OSD (on-screen display) function, and includes the following calibration.

  That is, the projector 1 has an input signal processing unit 2 including an input connector for connecting various external video devices including a personal computer. The input signal processing unit 2 performs analog-digital conversion on various video signals such as RGB signals and video signals input from an external video device via a cable, and converts them into video signals of a predetermined format (YUV signals, etc.) The image is sent to the image conversion unit 3 via the system bus SB.

  The image conversion unit 3 performs image processing such as hue adjustment, enlargement / reduction, vertical and horizontal trapezoidal distortion correction on the video signal after digital conversion in accordance with an instruction from the control unit 4, and the processed video The signal is sent to the projection encoder 5.

  The projection encoder 5 is a frame synthesizing unit of the present invention, and develops and stores the image data based on the image-processed signal in the video RAM 6 and then generates a video signal based on the stored data in the video RAM 6 to generate a projection drive unit. 7 is output. At that time, if necessary, the OSD data sent from the OSD control unit 8, that is, various menu screens and setting screens to be displayed superimposed on the video by the OSD function, and a video frame described later are combined with the image data. .

  The projection drive unit 7 generates a drive signal according to the transmitted image signal, and drives the light modulation element in the projection display unit 9 by the drive signal.

  The projection display unit 9 is mainly composed of a light source lamp (halogen lamp, metal halide lamp, high-pressure mercury lamp, etc.) and a reflector, a spectroscopic optical element (mirror, microlens, various prisms, color wheel, etc.) corresponding to various projection methods, a light source Consists of the light modulation elements (DMD, transmissive liquid crystal device, reflective liquid crystal device, etc.) corresponding to various projection methods for modulating the light beam incident from the lamp via the spectroscopic optical element according to the input video signal. .

  Then, the light modulation element is driven at a predetermined frame rate (for example, 30 frames / second) by the drive signal generated by the projection drive unit 7, so that the modulated light beam is projected as projection light. Is projected onto an arbitrary screen, and a document or other still image or moving image based on the input video signal is enlarged and projected onto the arbitrary screen.

  Further, the projector 1 is provided with the key input unit 10 and the brightness detection unit 11.

  The key input unit 10 is a power key, a MENU key for displaying the menu screen and the setting screen, cursor keys for up / down / left / right directions used for selection of setting items on the setting screen, keystone distortion correction operation, etc. , Comprising a plurality of operation keys including an ENTER key used for determining setting contents, etc., and outputting a key input signal corresponding to the key operation contents by the user to the control unit 4.

  The brightness detection unit 11 is a second detection unit of the present invention, and includes a photosensor (photoconductive cell, photodiode, phototransistor, photocell, etc.), an amplifier for amplifying the output of the photosensor, and A / D It comprises a converter, detects the brightness around the projector 1, and outputs a detection signal to the control unit 4.

  The control unit 4 is a microcomputer including a CPU and its peripheral circuits, a ROM, and a RAM. The CPU follows a program stored in the ROM and receives a key input signal sent from the key input unit 10. By operating accordingly, each part of the projector 1 is controlled. While the projector 1 projects an arbitrary image while performing trapezoidal distortion correction, processing described later is executed according to the program, and at that time, the projector 1 functions as detection means of the present invention.

  Next, the contents of the outer peripheral frame display process executed by the control unit 4 at a constant processing interval (for example, 0.5 second interval) will be described with reference to the flowchart of FIG.

  Here, it is assumed that the projector 1 projects an arbitrary image while performing trapezoidal distortion correction as shown in FIG. In this state, as described above, the peripheral projection area 101 with the trapezoidal distortion is present outside the projected image 100 in the correction state on the screen, and can be recognized. It is.

  In addition, the correction amount at the time of correcting the keystone distortion is displayed by OSD a trapezoidal distortion correction setting screen (not shown) on the projection screen in accordance with a predetermined key operation by the user, and the vertical and horizontal correction amounts in this state are displayed. This is the correction amount at the time when the user presses the enter key while changing the correction amount individually in accordance with the operation of the up / down / left / right cursor keys and simultaneously reflecting the changed correction amount in the projected image.

  Then, as shown in FIG. 2, in the outer frame display process, the control unit 4 first obtains luminance information included in the input video signal from the image conversion unit 3, so that the brightness of the projected video at that time is predetermined. It is determined whether or not it is below the reference (step S1). In the present embodiment, the above determination is performed using the average value of the luminance of each pixel in one screen as the brightness of the projected image. If the determination result is NO and the input video is relatively bright, the process is completed as it is.

  On the contrary, if the brightness of the projected image is below a predetermined reference (YES in step S1), the brightness around the apparatus main body is continuously below the predetermined reference based on the detection signal sent from the brightness detection unit 11. It is discriminate | determined whether it is (step S2). Further, even when the result of the determination is NO and the usage environment is a relatively bright environment, the processing is completed as it is.

  On the other hand, if the result of the determination is YES, that is, if the brightness of the input video and the brightness around the device body are both darker than a predetermined reference, whether the input video is a still image or a moving image Is determined (step S3).

  This determination is made by setting the type of the input video in advance by the user and confirming the setting contents, or automatically based on the input video signal. When performing automatically, for example, the luminance values of pixels of a specific line are integrated for each frame, and if there is no change in the integrated luminance value between frames or if it is below the reference, it is determined as a still image, and the change is the reference If it is larger than that, it is determined to be a video.

  When the input video is a still image, the color and line type of a video frame (see FIG. 4A), which will be described later, are set for still images (step S4). The frame color and line type are set for the moving image (step S5). Note that the colors and line types set here are determined in advance based on experience.

  Thereafter, the OSD control unit 8 is prepared in advance with a frame corresponding to the correction amount of the above-described trapezoidal distortion correction, and a still image or moving image color frame and line type set in step S4 or step S5. The image data is generated based on the image frame pattern data, and is displayed in the OSD on the outer peripheral edge of the image after the trapezoidal distortion correction by the projection encoder 5 (step S6), thereby completing the processing.

  FIG. 4A is a diagram showing a projection state when the brightness of the input video and the brightness around the apparatus main body are both darker than a predetermined reference in the above processing.

  In this state, since the video frame 200 exists on the outer periphery of the projected video 100 on the screen, the boundary between the projected video 100 and the peripheral projection area 101 becomes clear. Therefore, even in an environment where the projected image 100 is dark and the periphery of the apparatus main body is dark so that the outer shape of the peripheral projection area 101 can be easily recognized, the sense of incongruity caused by the presence of trapezoidal distortion in the peripheral projection area 101 is eliminated. can do. Therefore, even when performing trapezoidal distortion correction, it is possible to always ensure a good projection state without any sense of incongruity.

  In the present embodiment, a case has been described in which the control unit 4 executes the above-described outer peripheral frame display processing at a constant processing interval while an arbitrary video is being projected. 4 may be configured to execute the above-described outer peripheral frame display process only once immediately after the start of image projection. Further, the processing interval when the outer peripheral frame display processing is executed at a constant processing interval is arbitrary.

  Further, the above-described video frame 200 is displayed when both the brightness of the input video and the brightness around the apparatus main body are darker than a predetermined reference. The video frame 200 may be automatically displayed when only one of the brightness around the main body is darker than a predetermined reference.

  Further, it may be configured such that the presence / absence of display of the video frame 200 can be manually set regardless of the brightness of the input video and the brightness around the apparatus main body. In this case, for example, when a predetermined key operation is performed by the user, the display of the video frame 200 is started or ended in response thereto, or the setting item regarding the operation content of the projector 1 is set in the video frame. An item relating to the display of 200 may be provided in advance, and the video frame 200 may be displayed unconditionally in a state in which the item is turned on.

  Further, in the present embodiment, the video frame 200 has been described as being displayed by the OSD function that displays various menu screens and setting screens on the screen as necessary. A configuration may be adopted in which the data in the video frame 200 is directly combined with the video input in the unit 3, that is, the image before the trapezoidal distortion correction or the corrected image.

  In this embodiment, two types of video frames 200 are prepared for still images and moving images, and the colors and line types (attributes) of the video frames 200 are different depending on whether the input video is a still image or a moving image. However, the color and line type of the video frame 200 may be the same regardless of the type of the input video.

  In addition, the color and line type of the video frame 200 are simply changed according to the type of input video such as still image and video, but further, the color of the video frame 200 according to the content for still image and video. Other attributes other than the line type may be changed.

  For example, the color of the video frame 200 may be changed according to the overall color tone of the input video. In that case, a table showing colors according to the color tone is prepared in advance, and in the above-described outer peripheral frame display process, the overall color tone of the input video is confirmed by an arbitrary method in step S3, and in the subsequent step S4, The color corresponding to the confirmed color tone may be acquired from the table and set as the color of the video frame 200. Of course, not only the color but also other attributes such as line type (including lines expressed by continuous patterns) and line width may be changed according to the input video.

It is a block diagram which shows the projector which concerns on this invention. It is a flowchart which shows the outer periphery frame display process in a control part. It is a figure which shows the projection state when the projector is performing the trapezoid distortion correction. It is explanatory drawing which shows the difference between the projection state (a) in which the image frame is displayed, and the projection state (b) in which the image frame is not displayed when the projection image is dark.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Projector 2 Input signal processing part 3 Image conversion part 4 Control part 5 Projection encoder 8 OSD control part 11 Brightness detection part 100 Projection image 101 Peripheral projection area 200 Image frame SB System bus

Claims (8)

In a projector having a correction function for correcting a trapezoidal distortion generated in an image when an image based on an input image signal is projected onto an arbitrary projection target,
A projector comprising frame composition means for synthesizing a video frame with an outer periphery of the video when projecting the video accompanied by correction by the correction function. Detecting means for detecting the brightness of the image;
The projector according to claim 1, wherein the frame synthesizing unit synthesizes a video frame with an outer periphery of the video when the brightness of the video detected by the detection unit is equal to or less than a predetermined reference. A second detecting means for detecting ambient brightness under a projection environment;
The frame synthesizing unit synthesizes a video frame with an outer periphery of the video when the ambient brightness detected by the second detection unit is equal to or lower than a predetermined reference. The projector described. Setting means for setting an attribute of the video frame based on the image signal;
The projector according to claim 1, wherein the frame synthesizing unit synthesizes an image frame having an attribute set by the setting unit on an outer periphery of the recorded image.   5. The projector according to claim 1, wherein the frame synthesizing unit synthesizes an image frame with an outer peripheral edge of an image corrected by the correction function.   5. The projector according to claim 1, wherein the frame synthesizing unit synthesizes an image frame with an outer peripheral edge of an image based on an input image signal before correction by the correction function. An image projection method in a projector having a correction function for correcting a trapezoidal distortion generated in an image when an image based on an input image signal is projected onto an arbitrary projection target,
An image projection method comprising: synthesizing an image frame with an outer peripheral edge of an image when projecting an image accompanied by correction by the correction function. A computer having a projector having a correction function for correcting trapezoidal distortion generated in an image based on an input image signal and projected on an arbitrary projection target;
A program for executing processing for synthesizing a video frame on the outer periphery of the video when projecting the video accompanied by correction by the correction function.

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