JP2014044369A - Image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image display device capable of providing many viewers with a screen that is easy to watch.SOLUTION: A image display device comprises: image input means 12 for receiving image data including one kind or more of image component objects; image processing means 14 for processing the image data inputted by the image input means to generate an image for display; image display means 13 for displaying the image data inputted by the image input means in an image display surface 200; distance information acquisition means 11 for detecting distance information between each of the plurality of viewers and the image display surface or acquiring the distance information from a distance detection device; object discrimination means 24 for discriminating an object included in the image data; and image processing means 25 for performing processing which improves visibility of the image data on the image display surface on the image data in accordance with the kind of the object discriminated by the object discrimination means and the distance information acquired by the distance information acquisition means.

Description

  The present invention relates to an image display device that displays input image data.

  In meetings and the like, viewers often view and discuss common information. For display of information, a display device having a large screen is preferable, and a projector, a large screen flat panel display, an electronic blackboard, or the like is used.

  Since the size of the screen of the display device affects the visibility, a technique for presenting an appropriate number of viewers based on the size of the screen has been proposed (for example, see Patent Document 1). In Patent Document 1, when a user inputs a projector model, a screen size, and an arrangement of a viewer's desk, a viewing area recommended for viewing a projected image, the number of viewers, and an environment at the time of image projection are described. A projector selection support server that visually displays information such as brightness (whether or not the room can be lit) is disclosed.

  In addition, a technique for adjusting the size of the screen so as to obtain good visibility has been proposed (see, for example, Patent Document 2). Patent Document 2 discloses a projection device that projects an image so that the character size is constant even when the distance between the screen and the projector or the distance between the viewer and the screen changes.

  However, the projector selection support server disclosed in Patent Document 1 is merely a technique for notifying a viewing area according to the arrangement of a desk or the like, and adjusts the screen, character size, and the like when the number of viewers changes. I can't.

  In addition, the projection device disclosed in Patent Document 2 cannot provide an optimal image to a large number of viewers even if the character size is appropriately maintained for a single viewer. There is.

  Moreover, in patent document 2, there exists a problem that it is not considered about objects other than a character. When objects other than characters are adjusted to a certain size, jaggy and noise may be noticeable among viewers close to the screen among a large number of viewers.

  As described above, the conventional screen display method has a problem in that an optimal image cannot be provided to a large number of viewers in consideration of objects.

  In view of the above problems, an object of the present invention is to provide an image display device that can provide an easy-to-view screen for a large number of viewers.

  In view of the above problems, the present invention provides an image input means for inputting image data including one or more types of objects of image components, and an image for display by processing the image data input from the image input means. Detecting the distance information between each of a plurality of viewers and the image display surface, the image processing means for generating the image data, the image display means for displaying the image data input by the image input means on the image display surface, Or distance information acquisition means for acquiring the distance information from a distance detection device, object determination means for determining the type of object included in the image data, and the object type and distance information acquisition determined by the object determination means An image to be processed to improve the visibility of the image data on the image display surface according to the distance information acquired by the means And processing means, characterized by having a.

  An image display device that can provide an easy-to-view screen for a large number of viewers can be provided.

It is an example of the figure explaining schematic operation | movement of the projector of this embodiment. It is an example of the schematic block diagram of an image projection system. It is an example of the functional block diagram of a projector. It is an example of the figure which illustrates image projection of 3LCD system typically. It is an example of the figure which illustrates the detection method of distance typically. It is an example of the figure which illustrates the detection method of distance typically It is an example of the figure which illustrates the detection method of distance typically It is an example of a schematic block diagram of a positional information management system. It is an example of the figure which extracts and shows the communication apparatus, wireless terminal, and management apparatus which comprise a wireless network in FIG. It is an example of a functional block diagram of an image processing unit. It is an example of the figure which shows a projector and a viewer typically. It is an example of the flowchart figure which shows the process sequence of the image process part when the image data mainly containing a character are input. It is an example of the figure explaining the relationship between the viewer of FIG. 11, and the character size expanded. (Example 2) which is an example of the flowchart figure which shows the process sequence of the image process part when the image data mainly containing a photograph or a graphics image are input. (Example 3) which is an example of the flowchart figure which shows the process sequence of an image process part. It is a figure which shows an example of the allowable magnification determination table by which the allowable magnification was calculated | required with respect to the ratio of a noise pixel, and the minimum value of distance. FIG. 12 is an example of a diagram illustrating a relationship between the viewer of FIG. 11 and the size of an object to be enlarged. (Example 4) which is an example of the flowchart figure which shows the process sequence of an image process part. It is an example of the figure which illustrates typically the determination method of a projection limit enlarged size. It is an example of the figure which illustrates typically the determination method of a projection limit enlarged size. (Example 5) which is an example of the flowchart figure which shows the process sequence of an image process part. It is an example of the figure which illustrates an expansion / reduction process typically. (Example 6) which is an example of the flowchart figure which shows the process sequence of an image process part. It is an example of the figure explaining determination of the deletion character size.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is an example of a diagram illustrating a schematic operation of the projector according to the present embodiment. Image data is input to the projector from a computer, an MFP (Multi Function Printer), or a portable memory.

  The projector determines the type of object included by analyzing the image data. Objects include photographs, graphics, text, and animation. Further, the projector detects the viewer and also detects the distance from the screen to each viewer.

Then, the projector controls the size of the object or screen to be displayed as follows, for example, according to the type of the object and the distance from the screen to the viewers a and c.
(i) When the object is, for example, a character The character size is enlarged according to the distance to the viewer c. In the case of characters, the character size is increased as the distance to the viewer c is longer. Thereby, the distant viewer c can read the characters, and the near viewer a can also read the characters.
(ii) When the object is a photograph or graphic The size of the photograph is enlarged according to the distance to the viewer c, but not larger than the upper limit set by the distance to the nearby viewer a. In the case of a photograph, if there is a certain size, a distant viewer c can discriminate the photographed object. Also, if the photograph is made too large, jaggy and noise will be noticeable by the nearby viewer a, but by setting an upper limit, the image quality for the nearby viewer can be maintained.

  As described above, the projector according to the present embodiment determines an object and detects a distance from each viewer. Thereby, even if there are a large number of viewers, it is possible to adjust the size of the screen or the object to an optimal size that is easy for a remote viewer and a nearby viewer to easily see according to the object.

[Configuration example]
FIG. 2 shows an example of a schematic configuration diagram of the image projection system. An external PC terminal 300 or an MFP 400 is connected to the projector 100 via a network (or directly). Image data is input to the projector 100 from the external PC terminal 300 or the MFP 400. The network may be either wired or wireless.

  In addition to connecting video output terminals such as HDMI and D-SUB to the projector 100, the external PC terminal 300 transmits image data in an electronic file format (for example, JPEG, GIF, MPEG2, etc.) to the projector 100 via a LAN or the like. To do.

  The MFP 400 is a multi-function printer, but in the present embodiment, it is preferable to have a scanner function as an image reading apparatus. The MFP 400 scans the original, performs image processing optimal for paper output (such as faithfully reproducing the original image on the transfer paper), and prints a copy image. Further, the image data that has been subjected to image processing optimal for display on the read image and converted into an image format such as JPEG is transmitted to the projector 100 via a LAN or the like.

  The external PC terminal 300 and the MFP 400 are examples of devices that provide image data to the projector 100, and the projector 100 reads stored image data even if a user attaches a nonvolatile memory such as a USB memory to the projector 100. be able to.

  The projector 100 projects the image data input to the projector 100 onto the image projection plane 200 after performing image processing optimal for image projection. A typical example of the image projection surface 200 is a screen (a screen dedicated to projector projection; enables high-quality projection images). However, the user can image a wall or whiteboard in a conference room having white or light pastel colors. The projection surface 200 can be used alternatively.

  The projector 100 is an example of the image display device in the claims, and the object enlargement method of the present embodiment can be applied to a large screen flat panel display. In this case, although there is a physical limitation on the size of the projection plane, a portion of the image data that cannot be projected can be displayed by a scroll operation or the like.

  FIG. 3 shows an example of a functional block diagram of the projector 100. The projector 100 is controlled by a controller 12, and a distance calculation unit 11, an image projection unit 13, an image processing unit 14, and an operation input unit 15 are connected to the controller 12.

  The operation input unit 15 is a hard key that receives a user's operation, a soft key displayed on a touch panel type liquid crystal, or a voice input device. In addition, a command can be received from the external PC terminal 300 or the MFP 400 to accept an operation.

  Image data input from an external PC terminal or the like is input to the image processing unit 14 via the controller 12. The image processing unit 14 processes the image data for image projection. For example, the resolution of the image data is converted to a resolution that the projector 100 supports, the image is decomposed into RGB images, the predetermined color signal is emphasized / attenuated, and the sharpness around the image is increased. I do.

  Note that the image processing unit 14 determines an object included in the image data as one of the characteristic portions of the present embodiment.

<Image projection unit>
The image projection unit 13 projects an image on the image projection surface 200. Image projection methods include an LCD method using transmissive liquid crystal, an LCOS method using reflective liquid crystal, and a DLP method using micromirrors. In this embodiment, a 3LCD (liquid crystal transmission type 3 plate type) using three reflection type liquid crystals will be described, but any projection method may be used.

FIG. 4 is an example of a diagram schematically illustrating the 3LCD image projection unit 13.
The light source 131 is a high-pressure mercury lamp or the like and emits white light. The first dichroic mirror 132 transmits, for example, light of R (red) wavelength and reflects light of G (green) and B (blue) wavelengths.

  The R (red) light is totally reflected by the mirror 135, collected by the lens 140, and then enters the LCD (R) 1381. Light of G (green) and B (blue) wavelengths is incident on the second dichroic mirror 133. The second dichroic mirror 133 reflects light of G (green) wavelength and transmits light of B (blue) wavelength. The G (green) light is collected by the lens 141 and enters the LCD (G) 1382. Light having a wavelength of B (blue) is totally reflected by the mirrors 134 and 138, collected by the lens 142, and then enters the LCD (B) 1383.

  Each LCD is controlled by the controller 12 by image data to be projected. That is, the transmission amount of each pixel of the LCD (R) 1381 is controlled based on the R component of the image data, and gradation control of R (red) is performed. Similarly, the transmission amount of each pixel of the LCD (G) 1382 is controlled based on the G component to perform G (green) gradation control, and the transmission amount of each pixel of the LCD (B) 1383 is controlled based on the B component. Then, gradation control of B (blue) is performed.

  The light of each color that has passed through each LCD enters the dichroic prism 139. The dichroic prism 139 reflects light of R (red) wavelength by 90 degrees, transmits light of G (green) wavelength, and reflects light of B (blue) wavelength by 90 degrees. As a result, the light of each color wavelength that has passed through each LCD is combined, and the combined light is condensed and scaled by the projection optical system 136 and projected onto the image projection plane 200.

  The controller 12 can adjust the projection size by enlarging / reducing the projected image by moving the lens of the projection optical system 136 along the optical axis by driving the actuator. Further, it is assumed that the controller 12 always grasps and manages the magnification set (controlled) in the optical system.

<Distance calculation unit>
The distance calculation unit 11 detects the distance between the image projection plane 200 projected by the projector 100 and each of a plurality of viewers. Hereinafter, the following methods and configurations (i) to (v) will be described as examples of distance calculation.

(i) When a stereo omnidirectional camera using an omnidirectional fisheye lens camera is installed in the projector 100 FIG. 5 is an example of a diagram schematically illustrating a distance detection method. The projector 100 is provided with “omnidirectional fisheye lens + CMOS sensor” at the top. Since the omnidirectional fisheye lens can focus and focus on all 360 degrees around the projector 100, a CMOS sensor can shoot an object around 360 degrees.

  In addition, by superimposing two omnidirectional fisheye lenses on the top and bottom and using two CMOS sensors, the omnidirectional camera 112 can obtain a pair of parallax images having different parallaxes around the entire circumference of the projector 100. Therefore, if the principle of the stereo camera is used, the distance from the projector 100 to the subject can be measured using camera parameters such as a focal length and a pixel pitch. Note that the image captured by the omnidirectional camera 112 has a very large lens distortion and the like, and thus distortion correction and the like are performed by image processing.

A viewer as a subject is recognized using, for example, face recognition technology. As a specific face recognition technique, a known method may be used, and the following is an example.
a. Prepare a number of detection template images in which the shadow is replaced with a black and white image for each portion, focusing on the shadow characteristic of the face. For example, the apex of the nose is bright and is represented by white pixels, and the surrounding area is dark and is represented by black pixels.
b. Binarize the face detection target image data.
c. Match the image data with the template image and vote for the matched pixels in the image data. This is performed for all template images.
d. Since the area where the face is reflected should have a large number of votes, the number of votes is compared with the threshold value for each pixel, and the area where pixels equal to or greater than the threshold value are consecutive is determined to be the area where the face is reflected. . If the viewer's face can be recognized, the viewer's direction can also be specified.

  The image projection plane 200 is detected as follows, for example. Since the projection direction of the image is fixed, an approximate pixel range in which the projection image is photographed among the images photographed by the omnidirectional camera 112 is known. In addition, since the range where the image is taken has a luminance of a predetermined value or more and a rectangular shape, it can be easily detected by binarization and pattern matching. Since the magnification of the optical system is a control value, if the magnification is a predetermined value, there is a certain relationship between the image size and the distance to the image projection plane 200. Therefore, if the size of the image is known, the distance can be obtained. More precisely, displaying the arbitrary test pattern by the projector 100 increases the image detection accuracy. For example, if the test pattern is a checkered pattern, the image can be easily detected and the distance detection accuracy can be improved.

As described above, the distances B1 and B2 between the projector 100 and the viewer and the distance A between the projector 100 and the image projection plane 200 can be detected as shown in FIG. Further, since the viewer's direction is specified, the angles C1 and C2 formed by the straight line connecting the projector 100 and the image projection plane 200 and the straight line connecting the projector 100 and the viewer become clear. Therefore, the distance between the image projection plane 200 and the viewer can be obtained by the cosine theorem.
S1 = √ (A ² + B1 ² −2A · B1 · CosC1)
S2 = √ (A ² + B2 ² −2A · B2 · CosC2)
(ii) When a stereo camera is mounted on the image projection plane 200 FIG. 6 is an example of a diagram schematically illustrating a distance detection method. A stereo camera 113 is installed on the image projection plane 200. Since the stereo camera 113 acquires parallax information for each pixel, the distance can be detected for each pixel. In addition, since the viewer can be detected by the face recognition technology, the distance to each viewer can also be acquired.

(iii) Configuration in which Stereo Camera is Mounted on Short-Focus Projector 100 FIG. 7A is an example of a diagram schematically illustrating a distance detection method. When an image is projected by a short focus projector, it may be considered that a viewer basically exists only behind the projector 100. Therefore, if the stereo camera 114 is disposed at the rear of the short focus projector, almost all viewers can be photographed. Therefore, the distance from the projector 100 to the viewer can be detected.

  The distance to the image projection plane 200 is calculated by, for example, an ultrasonic sensor. An ultrasonic sensor is a sensor that calculates a distance from the time it takes an ultrasonic wave to return. In addition, since the projection distance of the short focus projector is often a short fixed value, even if the distance to the image projection plane 200 is regarded as the recommended projection distance, the distance from the image projection plane 200 to the viewer is limited. There is no big error.

(iv) Configuration of Stereo Camera + Motor FIG. 7B is an example of a diagram schematically illustrating a distance detection method. Even if a stereo camera 115 and a motor 116 that rotates the stereo camera 115 horizontally once are arranged in the projector 100, the omnidirectional camera of (i) can be obtained. When the projector controls and detects the rotation amount of the motor 116, the direction of the optical axis of the stereo camera 115 (which direction the image projection plane is in) can be specified. Therefore, the distance to the image projection plane 200 can be obtained.

  Similarly to the above, the viewer is detected by face detection, and the distance between the person and the projector is calculated. Since the rotation amount of the motor is detected, the direction of the viewer can also be specified. Accordingly, the distance between the projector 100 and the viewer can be calculated as in (i).

(v) Configuration using the indoor tatami mat management system FIG. 8 shows an example of a schematic configuration diagram of the location information management system. The location information management system includes communication devices 101, 102, 104, 106, wireless terminals 120, 122, 124, 126, 128, a management device 140, a management server 160, a network composed of communication devices, wireless terminals, and management devices. 180 and a network 190. Here, the network 180 is a wireless network managed by the management device 140. FIG. 9 shows the communication devices 101, 102, 104, and 106, the wireless terminals 120, 122, 124, 126, and 128, and the management device 140 that constitute the wireless network in FIG.

  The communication apparatuses 101, 102, 104, and 106 are fixed to, for example, the ceiling of a room, and position information (hereinafter referred to as “position information”) such as history information, the number of floors of a building, and a building number relating to the fixed position. This is transmitted wirelessly continuously or intermittently. Each communication device has an independent casing and operates by being supplied with power from a pre-installed power source, or is incorporated in a lighting fixture such as an LED fluorescent tube and operates with power supplied from the lighting fixture. Each of the communication devices 101, 102, 104, and 106 transmits position information held by each of the communication devices 101, 102, 104, and 106 to a predetermined range using a radio signal. The predetermined range is determined by the signal strength of the radio signal used. The communication device is arranged so as to cover an area that is a position management target, and is configured so that the respective areas do not overlap. Or even if it is a case where it overlaps, in the side which receives a positional information, it is comprised so that any one communication apparatus can be determined based on the intensity | strength of a received radio wave. In the example of FIG. 8, a conical dotted line shown below each communication device represents a predetermined range. As a communication method for transmitting position information, for example, a ground complementary signal (Indoor Messaging System; IMES) can be used.

  The wireless terminals 120, 122, 124, 126, and 128 can receive wireless signals transmitted by the nearest communication device among the communication devices 101, 102, 104, and 106. In the example of FIG. 8, each wireless terminal is attached to a rectangular parallelepiped management target that is a target whose position is to be managed. The wireless terminals 120, 122, 124, 126, and 128 are terminals such as active tags that can transmit radio waves themselves. Hereinafter, the wireless terminal 120 will be described.

  The wireless terminal 120 is in a range where it can receive a wireless signal from the communication device 101 and receives position information of the communication device 101. The position information of the communication apparatus 101 is received using, for example, IMES. The wireless terminal 120 transmits information including its own identification information such as a network address to the communication apparatus 101 together with the received position information. The transmission is performed through a network 180 by short-range wireless communication such as IEEE802.15.4 and ZigBee (registered trademark). In this case, IEEE802.15.4 abbreviated address or IEEE extended (MAC) address can be used as identification information of the wireless terminal 120. The identification information and position information transmitted to the communication device 101 are then transmitted to the management device 140 via the adjacent communication device 102. The transmission / reception operation in the wireless terminal 120 is performed at a timing determined in advance in the wireless terminal 120 or at a timing when a change in acceleration by the acceleration sensor included in the wireless terminal 120 is detected.

  The management device 140 connects the network 180 and the network 190 to each other, and bridges data transmitted from the network 180 side to the network 190. The management device 140 is installed, for example, for each floor of a building or for each room partitioned by walls. When the network 180 is a PAN (Personal Area Network) based on IEEE802.15.4 and ZigBee (registered trademark) and the network 190 is a LAN based on the IEEE802.3 standard, the communication system is converted between them. If the identification information of the wireless terminal 120 is represented by an IEEE 802.15.4 abbreviated address, it is converted into an IEEE extended address based on the information at the time of PAN configuration and transmitted to the management server 160.

  The management server 160 records the identification information and position information received via the management apparatus 140 together with the reception date and time, and manages the position of the communication apparatus. In the management server 160, management objects related to wireless terminals are recorded in advance. Therefore, the location of the management target can be searched using these pieces of information.

  The network 180 connects each communication device 101, 102, 104, 106, the wireless terminal 120, 122, 124, 126, 128, and the management device 140, for example, according to IEEE802.15.4 and ZigBee (registered trademark) standards. It is a configured PAN. When the PAN is configured with IEEE802.15.4 and ZigBee (registered trademark) standards, the wireless terminal, the communication device, and the management device each have an end device function, a router function, and a coordinator function defined by the ZigBee (registered trademark) standard. . Each communication device and wireless terminal enters the management of the management device at the time of activation, forms a PAN, and determines the minimum path to the management device.

  The network 190 is a network that connects the management apparatus 140 and the management server 160, and is, for example, a LAN defined by the IEEE 802.3 standard.

  As described above, in the location information management system 1 according to the embodiment of the present invention, the wireless terminal can transmit the identification information and the location information to the management server using power that can be communicated with the nearest communication device. it can. In addition, it is not necessary to install a new infrastructure for installing the communication device, and the introduction cost can be reduced.

  Note that the location information of the communication device may be provided through the network 180. This eliminates the need for transmission means for transmitting position information such as IMES.

  Further, the wireless terminal may transmit the identification information and the position information to the management apparatus 140 when the management apparatus is present in the vicinity of the communication apparatus that transmitted the position information. Thereby, identification information and position information can be transmitted to the management server by the shortest path.

  Further, the management server function may be integrated into the management server. This eliminates the need for a separate management device.

  The wireless terminal may be a wireless terminal having a function equivalent to an active tag, such as a smartphone, PDA, PC, or smart meter. As a result, it is possible to manage the position information of the existing wireless terminal without attaching a tag.

  Further, in addition to the above-described position information, information for specifying a finer position, such as information representing a section in the room, may be included. As a result, finer location management is possible.

  The location management target may be a person. Thereby, the location of a person can be managed by the system 1.

  The network 180 may be configured using short-range wireless communication such as Bluetooth LE, ANT, Z-Wave, and the like. This makes it possible to manage position information of various wireless terminals.

  The network 190 may include a plurality of types of networks such as the Internet. This makes it possible to manage the location information of the wireless terminal regardless of the physical location between the network 180 and the management server 160.

  As shown in FIG. 9, a wireless terminal 126 is added to the projector 100, and a wireless terminal 122 is added to the image projection plane (screen) 200. A mobile phone, PDA, tablet terminal, etc. carried by the viewer are wireless terminals. It has the same function as 124 and 128.

  In this case, the projector 100, the image projection plane (screen), and the position information of all viewers are all transmitted to the management server 140. Since the management server 140 notifies the projector 100 of the position information via the network, the distance calculation unit 11 can also acquire the position information of the image projection plane (screen) and all the viewers.

  The distance calculation unit 11 calculates the distance between the image projection plane (screen) and each viewer from each position information (the distance between the projector and the image projection plane and between the projector and the viewer can also be calculated).

  Instead of calculation by projector 100, management server 140 may calculate distance information and transmit it to projector 100.

<Distinguishing objects>
FIG. 10 shows an example of a functional block diagram of the image processing unit 14. The image processing unit 14 is controlled by the image processing controller 23 and communicates with the controller 12 of the projector 100. A ROM 21, a RAM 22, an image recognition unit 24, and an image processing unit 25 are connected to the image processing controller 23. The image processing controller 23 stores the distance information of each viewer detected by the distance calculation unit 11 in the RAM 22, acquires externally input image data, and develops it in the RAM 22 area as necessary.

  The image recognition unit 24 discriminates an object such as a character, a photograph, or a graphic from image data input from an external PC terminal or the like, and recognizes its position and size. These recognition contents are called feature amounts in the image area.

  For example, the image recognizing unit 24 determines the attribute of the object using the object information of the header part transmitted together with the image data. That is, when creating image data from a file created by an application that runs on the external PC terminal 300, an attribute of an object managed by the application is used. The attributes include not only the types of objects such as characters and photos, but also the character size, font type, color, position, and the like.

  In addition, the object attributes may be recognized by performing layout analysis or the like using only the image data. The object determination method in this case may be a known technique or a combination thereof. When detecting a photograph, first, a background color is obtained, and a connected component of pixels other than the background color is obtained as a candidate area of the photograph area. A circumscribed rectangle of a candidate area obtained by grouping pixels that can be regarded as the same color among the pixels other than the background color is obtained, and a photographic area is determined from the number of circumscribed rectangles and the overlapping method. For example, the background color is determined by clustering pixel values and determining the maximum cluster color as the background color.

  When detecting a character, the image data is binarized to obtain a circumscribed rectangle of the connected component. Then, the character size is estimated from the size of the circumscribed rectangle and the histogram of the size, and is separated into the character region and the rest with reference to the density of the circumscribed rectangle. Note that the characters include numbers, alphabets, symbols, and the like.

  When a character area and a photographic area are mixed in the same image data, the image recognition unit 24 obtains a circumscribed rectangle of the area and specifies the position of the area by the position information of the diagonal vertex.

  Since the graphic is an image expressed by separately painting lines and curves and colors, it is detected by a method similar to that for photographs. In the photo area, the graphic is discriminated based on the number of colors and the size of the circumscribed rectangle. There is no need to distinguish between photos and graphics.

  The moving image is detected because it is determined as a photo area and the pixel value of the area constantly fluctuates.

  The image processing unit 25 acquires the distance information detected by the distance calculation unit 11 and the feature amount recognized by the image recognition unit 24, and processes the input image as necessary. The processing includes enlargement / reduction, object layout change, sharpness and color adjustment.

  Processing of image data performed by the image processing unit 25 according to the object type and distance information will be described. The configuration of the distance calculation unit 11 can be implemented by any of the configurations (i) to (v) described above, but will be described assuming that the distance is detected using the configuration (i) unless otherwise specified.

  FIG. 11 is an example of a diagram schematically showing the projector 100 and the viewer. As shown in FIG. 6, an omnidirectional camera 112 is mounted on the projector, and the omnidirectional camera 112 captures a viewer and a screen around the projector 100, and the distance from the screen of each viewer is detected. ing.

  FIG. 12 is an example of a flowchart illustrating a processing procedure of the image processing unit 25 when image data mainly including characters is input.

  First, the controller 12 receives input of image data (S10). The image data is transferred to the image processing unit 14. The image data is transferred to the image recognition unit 24 via the image processing controller 23, and the image recognition unit 24 determines the attribute of the object (whether it is a character or graphics).

  It is assumed that a character image is input this time (S11). Instead of the image recognition unit 24 discriminating, a video mode selected by the user may be prepared, and when the user selects the character video mode as the video mode using the operation input unit 15, it may be determined as a character image.

  Since it is determined that a character image has been input, the image recognition unit 24 specifies a character size (font size) in the image data (S12). The character size [pt (point)] is described in the object information of the header portion of the image data file. Alternatively, the circumscribed rectangle used to determine that the image is a character image is specified more.

  Next, the image recognition unit 24 calculates the actual character size on the screen (S13). The actual character size can be obtained from the distance information between the screen and the projector 100, the magnification information of the projection optical system of the image projection unit 13, and the character size in S12.

  First, a preset dpi value (for example, 96 dpi or 120 dpi) set in the external PC terminal 300 or the like is read from the value stored in the RAM 22. This is because even if the character size can be specified by the number of points, the size of the characters in the image data differs depending on the dpi value.

  Further, the image recognition unit 24 has a projection size formula f (L, V) for calculating a projection size according to the distance in advance. f (L, V) is an equation for obtaining the diagonal size of the projection size, where L is the distance between the projector 100 and the screen, and V is the magnification of the projection optical system.

For example, if the screen setting of the image data is dpi = 96 dpi, the character size in the image data can be obtained by the following equation. “1/72” is the length of one point.
Character size [dot] in image data = 1/72 x character size s x 96
Since the size of this character is vertical, the length of the diagonal line is “1.16 × size of character in image data” when the average aspect ratio of one character is 5: 3.

When the projection resolution is VGA (1024x768), the number of diagonal dots is 1280 dots. Since 1280 dots correspond to f (L, V), the character size S on the projection plane is obtained by the following equation.
S = (f / 1280) × 1.16 × size of characters in the image data In addition, instead of calculating in this way, region determination is performed from the image taken by the omnidirectional camera 112 of the distance calculation unit 11, and the characters on the screen are determined. The size may be calculated.

  Next, the image processing unit 25 specifies the maximum distance information among the plurality of distance information stored in the RAM 22 (S14). The maximum value is information on the distance between the viewer who is farthest from the screen and the screen.

  Basically, the legibility of text images is most important, but the viewer who is considered to be in the position with the lowest legibility is considered the viewer who is farthest from the screen. In order to ensure the legibility of the viewer farthest from the screen, the image processing unit 25 determines the character size based on the distance information of the person farthest from the screen.

The image processing unit 25 calculates the minimum allowable character size necessary for character interpretation based on the maximum distance information calculated in S14 (S15).
As a method of obtaining the size required for character interpretation, basically, experiment is performed to determine what size is required according to the distance from the screen, and the information is used. calculate.

As an example, there is a trial calculation that the viewing area is up to 250 times the height of characters projected with a font size of 20 points. From this calculation, the character size (height) on the projection must be 1/250 of the distance from the screen.
Example: If the distance is 20 m, the height of 20000 [mm] x 1/250 = 80 mm is required. Therefore, the allowable character size determined in step S15 is compared with the character size on the screen calculated in step S13. Determine whether processing is necessary or not.

  If the character size calculated in S13 is larger or the same as the allowable character size determined in S15 (No in S16), the image processing unit 25 does nothing in particular (S17).

When the character size calculated in S13 is smaller than the allowable character size determined in S15 (Yes in S16), the image processing unit 25 causes the characters in the image data to have the allowable character size obtained in step S15. Is enlarged (S18). The size X of the character font enlarged by the image processing unit 25 is calculated by the following equation.
X = A × C ÷ B
However, the character size of the input image obtained in S12 is A,
The actual character size on the screen obtained in S13 is B,
The allowable character size obtained in S15 is C.
If the image processing unit 25 processes the character size of the image data into the above X size, the character size on the screen becomes C, which is the allowable character size, and can be read by viewers farthest from the screen. Become.

  The image processing unit 25 enlarges the character having a character size less than X in the input image to the size X, and transmits the processed image data to the image projection unit 13 via the controller 12. The image projection unit 13 projects the image data with the enlarged characters on the image projection plane 200.

  Note that the enlargement process is not performed by the image processing unit 25 in the image processing unit 14, but the projection optical system of the image projection unit 13 can also perform optical enlargement, so that optical enlargement may be performed. . In other words, the image data is not processed in character units, but the entire image data is enlarged by the projection optical system using “C ÷ B” in the above equation as a variable magnification. Further, the enlargement of the image processing unit 25 and the optical enlargement may be combined to enlarge the character size to an allowable size or more.

  FIG. 13 is an example of a diagram illustrating the relationship between the viewer of FIG. 11 and the enlarged character size. FIG. 13A shows a projected image when the viewer a is farthest from the screen, FIG. 13B shows a projected image when the viewer b is farthest from the screen, and FIG. The projection images when the viewer c is farthest from the screen are shown. As shown in FIGS. 13A to 13C, the longer the distance between the screen and the viewer, the larger the character size in order to improve the legibility.

  Therefore, according to the projector 100 of the present embodiment, when the projection image is a character, the character size can be increased according to the distance from the viewer 100 farthest from the projector 100 among the plurality of viewers.

  In the present embodiment, processing of image data performed by the image processing unit 25 when a photograph or a graphics image is input will be described. For the same processing as in the first embodiment, only the main part will be described, and only the difference will be mainly described.

  FIG. 14 is an example of a flowchart illustrating a processing procedure of the image processing unit 25 when image data mainly including a photograph or a graphics image is input.

  Steps S20 and S21 are the same as S10 and S11 of the first embodiment. In this example, it was recognized that photographs or graphics were mainly included.

In step S22, the projection size on the projection screen is calculated by the same method as in step S13 of the first embodiment (S22). For example, in the case of a photograph or graphics, the length of the diagonal line of the photograph or graphics is obtained from the header of the image data file by the number of dots. Therefore, the size S of the photograph or graphics on the projection surface is obtained by the following equation.
S = (f / 1280) x 1/72 x photo or graphics size x 96
Instead of calculating in this way, it is also possible to determine the area from the image taken by the omnidirectional camera of the distance calculation unit 11 and calculate the size of the picture or graphics on the screen.

  In step S23, the image processing unit 25 specifies distance information having the smallest distance information between the screen and the projector 100 (S23).

  The image processing unit 25 calculates the projection allowable maximum size of the projection plane based on the minimum value specified in step S23 (S24). This is because, for a person close to the screen, if the projected image is made too large, the graininess of each pixel is conspicuous, and the appearance of photographs, moving images, etc. will be deteriorated. That is, the maximum allowable size that the viewer sees as a limit is determined based on the distance information of the person closest to the screen.

  Since the allowable maximum size also depends on the resolution, aspect ratio, and the like of the projector 100, it is preferable to basically perform an experiment, actually calculate the allowable limit value, and set the value.

  When an experiment was conducted as an example, the graininess was conspicuous when the projection size was equivalent to the distance from the screen. Therefore, in S24, the minimum value of the referenced distance information is set as the maximum allowable projection size.

  Step S25 is the same as S14 of the first embodiment.

  Next, the image processing unit 25 uses the maximum distance calculated in step S25 to determine the optimal projection optimal size for the farthest person who is estimated to be the most difficult to see the projection image (S26). The optimum projection size uses parameters calculated by experiments. As an example of a parameter, when viewing a home theater, a distance [meter] that is generally 0.025 to 0.03 times the screen size (diagonal line, unit is inch) is optimal. From this calculation, the optimum projection size [inches] is a value obtained by dividing the distance [meters] by 0.025 to 0.03. For example, if the distance from the screen is 3 [m], 3 / 0.025 = 120 [inch] is the optimum screen size.

  The optimal projection size is the screen size, but assuming that the graphic or photo is included so as to occupy the entire screen, the optimal screen size is the optimal graphic or photo size.

  Instead of using the person farthest from the screen as a reference, an average value of distances from the screens of the viewers may be calculated, and an optimum size may be determined based on the average value. Depending on the direction (scattering) from the viewer's screen, this is the optimum size for many viewers.

  The optimum projection size may be obtained from an appropriate constant such as 1/250 used for obtaining the allowable character size. When this constant is set to 10, when the distance is 10 [m], the height of 10 [m] × 1/10 = 1 m is the optimum projection size.

  Next, the image processing unit 25 compares the maximum allowable projection size determined in S24 with the optimal projection size determined in Step S26 (S27). By comparison, the smaller one of the maximum allowable projection size and the optimal projection size is selected.

  When both are equal or the projection allowable maximum size is larger (No in S27), the image processing unit 25 determines to enlarge the projection image to the optimum projection size (S28). Therefore, the scaling factor is obtained by comparing the projection size calculated in step S22 with the optimum projection size.

  On the other hand, when the optimal projection size is larger (Yes in S27), the image processing unit 25 determines to enlarge the projection image to the maximum allowable projection size (S29). Therefore, the scaling factor is obtained by comparing the projection size calculated in step S22 with the maximum allowable projection size.

  What actually enlarges the projection image is not the image processing unit 25 but the projection optical system of the image projection unit 13. The image processing unit 25 stores the scaling factor or projection size of the projection image to be converted in the RAM 22, transfers it to the controller 12 via the image processing controller 23, and finally inputs it together with the image data to the image projection unit 13.

  Here, the scaling process is performed by the projection optical system 136, but the image projecting unit 13 performs projection by setting the scaling factor of the projection size transferred from the image processing controller 23.

As described above, in this embodiment, as in the first embodiment, it is basically optimal for the person farthest from the screen where the projected image is most difficult to see, in a range that is not too large for the person closest to the screen. Images can be projected in size. Therefore, when the object to be projected is a photograph or a graphics image,
・ For viewers closest to the screen, the screen is so large that it reduces the demerit that the image quality is poor due to the graininess,
-It is possible to provide a projection image having a size that is most optimally perceived by a person farthest from the screen among the screen sizes allowed by the person closest to the screen.

  Note that this embodiment is not limited to photographs and graphics, but can be similarly applied to moving image information such as movies.

  In the present embodiment, as in the second embodiment, a photograph, graphics, or the like is used as an input image, but the projector 100 that selectively enlarges an object in image data instead of enlarging the entire projection image will be described. .

  FIG. 15 is an example of a flowchart illustrating a processing procedure of the image processing unit 25 of the present embodiment. Steps S40 and S41 are the same as S10 and S11 of the first embodiment. In this example, it was recognized that photographs or graphics were mainly included.

  In step S42, as in S22 of the second embodiment, the size of the photograph or graphics in the image data and the size of the photograph or graphics on the projection surface are calculated (S42).

Next, the image recognition unit 24 calculates the magnitude of noise caused by the image (S43). Noise refers to, for example, mosquito noise such as jaggy and JPEG, block noise, and the like.
For example, in the case of jaggy, it is confirmed how much jaggy exists with respect to an oblique edge portion. Jaggy is a phenomenon in which pixel values change steeply at the edge. Therefore, for example, a pixel (black pixel) having the same degree as a certain gradation value is continuously N pixels in a predetermined direction and has a gradation value that is more than a predetermined distance from the gradation value of the pixel ( It is detected that M white pixels) continue in the same direction. If the black pixels are interrupted, the same process is performed by shifting one step in a direction perpendicular to the predetermined direction. Thereby, it can be detected that a region in which black and white pixels are arranged in parallel exists in a staircase pattern.

  In the case of mosquito noise, it is understood how much mosquito noise is generated. For example, the decoded image is subjected to frequency conversion again to find an isolated frequency coefficient, and if there is an isolated coefficient, it will be easy to generate mosquito noise, and it will be expanded from those without an isolated coefficient. Need to be discreet. An isolated coefficient has a numerical value lower than that of a high-frequency coefficient and has an absolute value equal to or less than a certain threshold value. Since the one with a large remainder when quantized by the quantization table is likely to become mosquito noise, this property is utilized.

  Next, step S44 is the same as S23 of the second embodiment.

  In step S45, the image processing unit 25 obtains an allowable maximum enlargement size of the object based on the minimum distance (S45). When enlarging only the object in the image instead of enlarging the projection size, jaggy and mosquito noise become more noticeable as the image is enlarged. For this reason, it is necessary to determine how much of these noise factors can be tolerated through experiments.

  As an example of a simple implementation method, the image recognition unit 24 determines how much the total number of target pixels that are jaggy and target blocks that are mosquito noise calculated in S43 is relative to the total number of pixels. Then, the allowable magnification of the object is uniformly determined based on the distance from the screen.

  FIG. 16 is a diagram illustrating an example of an allowable magnification determination table in which an allowable magnification is obtained for the noise pixel ratio and the minimum distance value. If there is no jaggy or mosquito noise, the magnification of the object can be expanded up to 8 times regardless of the distance from the screen (in principle, it can be expanded as much as possible). If the cause of noise is 1% or less in both cases, the distance from the screen can be expanded up to 3 times when the distance is 1 to 3 m, and if it is between 3 and 6 m, it can be expanded up to 4 times, or 6 to 10 m. If it is 10m to 15m, it can be expanded up to 6 times.

  The further the distance from the screen, the more difficult it becomes to understand mosquito noise and jaggy even if the object is enlarged, so the greater the distance, the greater the enlargement tolerance. Further, as the ratio of the noise factor increases, it can be seen that when the image is enlarged, the noise becomes conspicuous. Therefore, when compared at the same minimum distance, the allowable enlargement rate becomes a smaller value.

  This is because if JPEG or other compressed images are projected, the higher the compression rate, the more likely mosquito noise and jaggy will occur. Therefore, the higher the compression rate, the smaller the allowable enlargement ratio and the lower the compression rate. This is the same as increasing the permissible enlargement ratio as the object increases.

  For this reason, if the input image is JPEG without obtaining mosquito noise or jaggy, the compression table included in the header portion of the file may be referred to estimate the degree of compression. Since each value in the quantization table is a value that divides the numerical value of the DCT result, the larger the value in the quantization table, the smaller the data. That is, it is highly compressed. Therefore, the compression rate can be estimated from the number of zeros and the average value of the quantization table. The allowable enlargement ratio can be determined according to the estimated size of the compression ratio.

  In this way, when the upper limit value of the enlargement ratio is calculated and the scaling process is performed with the upper limit value of the enlargement ratio with respect to the size of the object obtained in S42, the image recognizing unit 24 determines how large on the screen. Calculate what happens. This is called the allowable maximum enlargement size. The allowable maximum enlargement size is obtained by applying the allowable enlargement ratio to the magnification of the projection optical system of f (L, V) in S22 of the second embodiment.

  Next, S46 is the same as S25 of the second embodiment.

  Next, the image processing unit 25 uses the distance information of the person farthest from the screen obtained in S46 to determine an appropriate size of the object (S47). The appropriate size of the object is assumed to be the object size (height) on the projection of 1/250 of the distance from the screen, like the character size. This makes it easier to see objects such as photos and graphics.

  Next, the image processing unit 25 compares the optimum size of the object determined in S47 with the allowable maximum enlargement size determined in S45 (S48). The smaller of the optimal size of the object and the maximum allowable enlargement size is selected.

  When the optimum size of the object is larger (Yes in S48), the image processing unit 25 converts the target object to the allowable maximum enlargement size (S50).

  If the optimal size of the object is smaller or equal (No in S48), the image processing unit 25 converts the target object to the optimal size of the object (S49).

  The enlargement to a predetermined size by the image processing unit 25 is the same as S18 in the first embodiment.

  The image processing unit 25 transfers the image data subjected to the enlargement process in S49 or S50 to the image projection unit 13 via the image processing controller 23 and the controller 12. Thus, the image data is projected on the screen (S51).

  FIG. 17 is an example of a diagram for explaining the relationship between the viewer of FIG. 11 and the size of the object to be enlarged. FIG. 17A shows a projected image when the viewer a is farthest from the screen, FIG. 17B shows a projected image when the viewer b is farthest from the screen, and FIG. The projection images when the viewer c is farthest from the screen are shown.

  As shown in FIGS. 17A and 17B, as the distance between the screen and the viewer increases, the size of the object increases in order to improve legibility. However, as shown in FIGS. 17B and 17C, even if the distance is too far from the viewer b, the object is not enlarged. This is because when the size is increased as shown in FIG. 17 (b), jaggy, mosquito noise and the like become conspicuous in the circular tire portion and the oblique line portion of the vehicle body. The photograph of the car can be grasped without further enlargement, and the overall appearance can be emphasized rather than the details of the photograph by providing an allowable maximum enlargement size.

  As described above, in this embodiment, an object can be enlarged and projected at an optimal size that is not too large for the person closest to the screen to the person farthest from the screen where the projected image is most difficult to see. .

  In this embodiment, processing of image data performed by the image processing unit 25 when an image in which characters and objects other than characters (photographs or graphics) are mixed is input will be described.

  FIG. 18 is an example of a flowchart illustrating a processing procedure of the image processing unit 25 of the present embodiment. Step S60 is the same as S10 of the first embodiment. Step S61 is the same as S11 in the first embodiment. However, in this embodiment, it is assumed that characters and objects other than characters (graphics / photos) are mixed. Identify.

  In step S62, the image processing unit 25 determines the allowable character size for the character object by the method of S12 to S15 of the first embodiment. For objects such as graphics other than characters, the optimum size and allowable maximum enlargement size are determined for each object by the method of S42 to S47 of the third embodiment (S46).

  Note that it is only necessary to determine the allowable character size of a character having a larger character size according to the minimum character size, so that only one allowable character size is required.

  Step S63 is the same as S16 of the first embodiment.

  If it is not necessary to enlarge the character (No in S63), the process proceeds to the comparison process (S70 to 76) for the graphics object (S64).

  On the other hand, if it is necessary to enlarge the character size in step S63 (Yes in S64), the image processing unit 25 calculates the projection limit enlargement size (S65).

  The projection limit enlargement size is calculated because the image data includes objects other than characters. When a character object is enlarged to an allowable character size, it may overlap other objects or exceed the size (projection size) of image data. For this reason, it is confirmed whether there is no problem in enlarging to any size, and an upper limit enlargement size that is not problematic is determined as the projection limit enlargement size.

  FIG. 19 is an example of a diagram schematically illustrating a method for determining a projection limit enlargement size. As a calculation method of the projection limit enlargement size, the input image data is stored in the RAM 22 and the enlargement rate is enlarged from 100% to 110%, 120%, 130% and 10% increments, It is determined whether or not the overlap or projection size of the image data is projected (reach the outer edge of the image data).

  19 (a) shows an enlargement ratio of 100%, FIG. 19 (b) shows an enlargement ratio of 110%, FIG. 19 (c) shows an enlargement ratio of 120%, FIG. 19 (d) shows an enlargement ratio of 130%, and FIG. Image data with an enlargement ratio of 140% and FIG. 19F is an enlargement ratio of 150%.

  When the enlargement ratio is 150%, it is detected that the characters exceed the projection size. When an overlap is detected in this way, the enlargement process is stopped, and the size when the image is enlarged at an enlargement rate obtained by subtracting 10% from the current enlargement rate is set as the projection limit enlargement size. In this example, the size when the image is enlarged at an enlargement ratio of 140% is determined as the projection limit enlargement size.

  Next, the image processing unit 25 compares the projection limit enlargement size calculated in S65 with the allowable character size (S66). The smaller one of the projection limit enlargement size and the allowable character size is selected.

  When the allowable character size is larger (Yes in S66), the image processing unit 25 performs the enlargement process to the projection limit enlargement size (S67). When the allowable limit enlargement size is reached in this way, it is considered difficult to enlarge other graphics objects, so the processing ends here. That is, instead of proceeding to the graphic object enlargement processing step after S70, the enlarged image data is transferred from the image processing unit 25 to the image projection unit 13 via the image processing controller 23 and the controller 12, and the image is transferred. Projecting is performed (S68).

  If the projection limit enlargement size is greater than or equal to the allowable character size in step S66 (No in S66), the image processing does not overlap with the graphic or protrude the projected image even if the enlargement processing is performed up to the allowable character size. The unit 25 enlarges the character object to an allowable character size (S69).

Next, an enlargement process for objects other than characters is performed.
First, when there are a plurality of objects other than characters, the object of the smallest size is basically the most difficult to see, so the processes of S70 to S76 are performed on all objects in the order of the smallest object. .

  First, as in S48 to S50 of the third embodiment, the optimum size of the object and the allowable maximum enlargement size are compared (S70), and either the optimal size or the allowable maximum size of the object is selected as the enlargement size (S71, S71). S72).

  Next, as in step S65, the projection limit enlargement size of an object other than the focused character is calculated (S73).

  FIG. 20 is an example of a diagram schematically illustrating a method for determining the projection limit enlargement size. Here, the case where the enlargement ratio of characters is 120% in FIG. 19 is taken as an example. Therefore, the enlargement ratio of the characters is 120%.

  20 (a) shows an enlargement ratio of 100%, FIG. 20 (b) shows an enlargement ratio of 110%, FIG. 20 (c) shows an enlargement ratio of 120%, FIG. 20 (d) shows an enlargement ratio of 130%, and FIG. Image data with an enlargement ratio of 140%.

  When the enlargement ratio is 140%, it is detected that the graphic overlaps with the character. When an overlap or the like is detected in this way, the enlargement process is stopped, and the size when the image is enlarged at an enlargement rate obtained by subtracting 10% from the current enlargement rate is set as the projection limit enlargement size. In this example, the size when enlarged at an enlargement ratio of 130% is determined as the projection limit enlargement size.

  Next, the projection limit enlargement size of the object other than the character calculated in this way is compared with the size selected in either S71 or S72 (the maximum allowable size or the optimum object size). (S74). Again, the smaller of the comparison targets is selected.

  When the size selected in either S71 or S72 (allowable maximum size or optimal object size) is smaller or equal (No in S74), the image processing unit 25 sets the size of the object other than characters to the selected size. Enlargement processing is performed (S76).

  If the size selected in either S71 or S72 (the maximum allowable size or the optimum size of the object) is larger (Yes in S74), objects other than characters are enlarged to the projection limit enlargement size (S75).

  When S70 to S76 are performed for the number of objects other than characters and enlargement processing is performed for all objects, an image is projected (S77). The image data is transferred to the image projection unit 13 via the image processing controller 23 and the controller 12, and an image is projected on the screen.

  In this embodiment, as shown in FIG. 18, the character object is first enlarged and then the size of the object other than the character is determined in the case of the projected image of the projector 100 because the character is legible. This is because the priority is considered high. Pictures and graphics can be grasped to some extent even if they are a little small. However, since the processing order is not limited, if the priority of a photograph or graphics is high, the size of the character object may be determined after first enlarging the object other than the character. Which object is given priority can be set in the projector 100 by the user.

  Thus, in this embodiment, in image data in which characters and objects other than characters are mixed, the characters are made as large as possible, and the objects other than characters are not too large for the person closest to the screen. You can enlarge and project objects by size.

  In this embodiment, a projector 100 that reduces the size of an object other than a character in order to improve the legibility of the character in image data in which characters and objects other than the character are mixed will be described.

  In this embodiment, in order to simplify the description, a case where there is only one object other than a character will be described as an example. However, the following method is applicable even when there are two or more objects other than characters.

FIG. 21 is an example of a flowchart illustrating a processing procedure of the image processing unit 25 according to the present embodiment.
The processing of steps S80 to S86 is the same as S60 to S66 of the fourth embodiment. However, the sign of S86 is different.

  When the projection limit enlargement size is larger or equal (No in S86), the image processing unit 25 selects the allowable character size as the enlargement size (S87). In this case, since the allowable character size is smaller than the projection limit enlargement size, it can be enlarged to the allowable character size.

  Thereafter, since there should be a margin up to the allowable limit size, the image processing unit 25 executes the processing from step S70 to S77.

  When the allowable character size is smaller (Yes in S86), the image processing unit 25 selects the allowable character size as an enlarged size (S88). That is, S87 and S88 are the same. In step S88, since the enlargement process is performed to the allowable character size that is larger than the projection limit enlargement size, the character object overlaps the photo object. Therefore, objects other than characters are reduced.

FIG. 22 is an example of a diagram schematically illustrating the enlargement / reduction processing of the present embodiment.
FIG. 22A shows an input image, and FIG. 22B shows image data obtained by enlarging characters to an allowable size of 130%. As shown in FIG. 22B, since the allowable character size is larger than the projection limit enlargement size, the character overlaps the object of the photograph.

  Therefore, as shown in steps S89 and S90, the image processing unit 25 reduces the photo object that overlaps the character object while maintaining the allowable character size of the character.

  22C and 22D are examples of diagrams for schematically explaining the reduction process. While keeping the text object as it is (allowable text size), the overlapping photo objects are reduced in 10% increments. In FIG. 22C, the size of the photo object is 90%, but 90% still overlaps with the character object. Next, as shown in FIG. 22D, the photo object is reduced to 80%. Then, since the overlap between the character object and the photo object is eliminated, the photo object is determined as 80% as it is (S89).

  The image processing unit 25 reduces the size of the photographic object of the image data (S90). When the image processing unit 25 determines the size of the photographic object, the image data is transferred to the image projection unit 13 and output to the screen in the same manner as in the other embodiments (S91).

  The projector 100 according to the present embodiment gives priority to the legibility of characters, and even if the appearance of photographs and graphics other than characters is somewhat deteriorated, a projected image in which characters can be surely read by all viewers. Can project.

  In the present embodiment, a character image is input as in the first embodiment, and when there is character information smaller than a predetermined threshold in the image data, the projector 100 that erases the character information will be described.

  FIG. 23 is an example of a flowchart illustrating a processing procedure of the image processing unit 25 of the present embodiment. Steps S100 to S104 are the same as S10 to S14 of the first embodiment.

  Next, the image processing unit 25 determines an allowable character size and a deleted character size (S105). The determination of the allowable character size is the same as S15 in the first embodiment.

  FIG. 24 is an example for explaining the determination of the deleted character size. In FIG. 24A, the font size to be deleted is registered in association with the ratio of the character area to the entire screen and the maximum value of the distance obtained in S104. That is, even the character size of the numerical value shown in FIG.

  In FIG. 24A, the larger the character area ratio, the larger the character size that is to be deleted. This is because the larger the percentage of the character area, the more information the projection image has, so in order to improve the appearance of the screen, the characters to be deleted are further expanded and the characters are actively deleted. It is. On the other hand, when the ratio of the character area is small, there is a high possibility that the character area can be expanded to an allowable size, and therefore the character is not basically deleted.

  Also, according to the distance from the screen, the longer the distance, the harder it is to see the character screen, so the character size threshold to be deleted also increases.

  It should be noted that the deletion of character data should be less than 10% of the entire area, and if the area to be deleted exceeds 10% if the size of the character data determined in S105, it should be 1pt smaller than the size determined in S105. To delete. Decrease the character size by 1pt until it does not exceed 10%.

  Next, the image processing unit 25 deletes character data that is equal to or smaller than the deleted character size determined in step S105 (S106).

  FIG. 24B is an example of a diagram for schematically explaining deletion of character data. In FIG. 24B, there are character data A, B, and C, but the character data B is character data having a size equal to or smaller than the deleted character size. For this reason, the image processing unit 25 deletes the character data B. The image data is as shown in the center of FIG.

Steps S107 to S110 are the same as S16 to S19 in the first embodiment.
In step S109, the character data A and C of the image data from which the character data B has been deleted are enlarged. As a result, the image data becomes as shown at the right end of FIG.

  According to the projector 100 of the present embodiment, it is possible to enlarge a character having a larger size by positively deleting small characters according to the maximum distance. Therefore, it is possible to enlarge the character image by controlling the amount of information on the screen. .

  The first to sixth embodiments have been described above. However, the processing flow, threshold values, and data examples used in the present embodiment are merely examples, and are not limited to these.

  In this embodiment, the processing of the image processing unit 25 is an enlargement / reduction process. However, in order to improve the legibility of characters, the contrast intensity may be changed instead of the enlargement / reduction process. For example, if the viewer is not far away, the image can be projected as faithfully as possible on the original image, and the farther the viewer is, the stronger the contrast and the better the legibility.

  Furthermore, the processing of the first to sixth embodiments has been described on the assumption that the processing is performed by the projector main body, but there is no problem even if the image processing unit 14 operates on the server instead of the projector 100 as in the position information system. . For example, image processing is performed on the image data stored in the network storage on the server, the processed image data is transferred to the projector 100 via the network, and the projector 100 performs only the projection. A configuration such as this is also possible. The processing procedure is almost the same as in the first to sixth embodiments.

DESCRIPTION OF SYMBOLS 11 Distance calculation part 12 Controller 13 Image projection part 14 Image processing part 15 Operation input part 21 ROM
22 RAM
23 Image processing controller 24 Image recognition unit 25 Image processing unit 100 Projector 200 Image projection plane

Japanese Patent No. 2003-295309 JP 2007-108462

Claims (10)

Image input means for inputting image data including one or more types of image component objects;
Image processing means for processing the image data input from the image input means to generate an image for display;
Image display means for displaying the image data input by the image input means on an image display surface;
Distance information acquisition means for detecting distance information between each of a plurality of viewers and the image display surface, or acquiring the distance information from a distance detection device;
Object discriminating means for discriminating the type of object included in the image data;
Image processing means for performing processing on the image data to improve the visibility of the image data on the image display surface according to the type of object determined by the object determination means and the distance information acquired by the distance information acquisition means; And an image display device. When the object determining means determines that the object included in the image data is a character,
The image processing means processes the characters of the image data based on the maximum distance information among the distance information between each of the plurality of viewers acquired by the distance information acquisition means and the image display surface.
The image display device according to claim 1. When the object determining means determines that the object included in the image data is other than characters,
The image processing means includes
Determining the upper limit processing amount to be applied to the image data based on the minimum distance information among the distance information between each of the plurality of viewers acquired by the distance information acquisition means and the image display surface;
Of the distance information between each of the plurality of viewers acquired by the distance information acquisition means and the image display surface, a required processing amount required for the image data is determined by the maximum distance information,
Among the upper limit processing amount and the required processing amount, the image data is processed with a smaller processing amount,
The image display device according to claim 1. Image recognition means for evaluating image quality of the image data input from the image input means and creating image quality information;
An upper limit processing amount table in which the upper limit processing amount is registered in association with the image quality information and the distance information;
The image processing means determines the upper limit processing amount with reference to the upper limit processing amount table based on the minimum distance information and the image quality information.
The image display device according to claim 3. When the object determining means determines that the image data input from the image input means includes characters and objects other than characters,
The image processing means gives priority to a character object over an object other than a character, or prioritizes an object other than a character over a character object, depending on the type of the object preset as a priority object. Processing
The image display apparatus according to claim 1, wherein: The image processing means has a function of calculating a requested enlargement amount determined by the maximum distance information for a priority object;
A function of calculating a limit enlargement amount of a range that does not contact the outer edge of the object and the non-prioritized object and the image data when the object to be prioritized is enlarged,
Enlarging an object to be prioritized by a smaller enlargement amount of the requested enlargement amount and the limit enlargement amount,
The image display device according to claim 5. The image processing means gives priority to a smaller one of the requested enlargement amount determined by the maximum distance information for an object not prioritized and an appropriate enlargement amount determined by the minimum distance information for an object not prioritized. To determine the amount of object enlargement,
When the priority object is enlarged by the requested enlargement amount of the priority object, the non-priority object is enlarged by the limit enlargement amount in a range that does not contact the enlarged priority object and the outer edge of the image data.
The image display device according to claim 6. The image processing means includes
When the requested enlargement amount is larger than the limit enlargement amount, the object prioritized by the requested enlargement amount is enlarged,
Reduce non-priority objects to a size that does not touch the enlarged priority object,
The image display device according to claim 6. A size determination table in which deletion target sizes of character objects are registered in association with the distance information;
The requested processing means determines the deletion target size with reference to the size determination table based on the maximum distance information,
Deleting a character object having a size equal to or smaller than the deletion target size from the image data input from the image input means;
The image display device according to claim 1, wherein: The image processing means processes the image data by optically expanding the image data.
The image display device according to claim 1, wherein

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