Patent Publication Number: US-10791305-B2

Title: Image processing apparatus and image processing method

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a U.S. National Phase of International Patent Application No. PCT/JP2018/004981 filed on Feb. 14, 2018, which claims priority benefit of Japanese Patent Application No. JP 2017-036804 filed in the Japan Patent Office on Feb. 28, 2017. Each of the above-referenced applications is hereby incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     The present disclosure relates to an image processing apparatus, an image processing method, and a program. More particularly, the disclosure relates to an image processing apparatus, an image processing method, and a program for easily correcting a defocus blur. 
     BACKGROUND ART 
     Video image display systems involving a projector are often subject to a defocus blur occurring in an image displayed on a projection plane, the blur being caused primarily by a difference between light paths to a screen surface, diffusion of light thereon, and a performance of a lens used in the projector despite best efforts to focus on a plane screen. 
     There have been signal processing techniques for eliminating the defocus blur by estimating an amount thereof on the projection plane through inverse filtering computation using a camera and design values so as to project the image corrected by preliminary signal processing performed on the estimated blur amount. For example, PTL 1 proposes techniques that use design values such as the amount of MTF drop of the projector lens (i.e., an amount of blur calculated from the design values of the projector lens). 
     CITATION LIST 
     Patent Literature 
     [PTL 1] 
     JP 2008-131099 
     SUMMARY 
     Technical Problems 
     However, the technique for estimating a degree of blur using the design values such as the MTF drop amount have resulted in deviations from the true values due to the installation conditions of the projector and the diffusion of light over the screen surface for example. Also, the measurement by the camera requires using a measuring system in a projector system. 
     The present disclosure has been devised in view of the above circumstances. An object of the disclosure is therefore to correct a defocus blur easily. 
     Solution to Problems 
     According to one aspect of the present technology, there is provided an image processing apparatus including: a blur amount conversion section configured to convert a value of an installation environment condition representing a condition of an environment in which a projector is installed into an amount of blur at a time of projection; and a corrected image generation section configured to generate a corrected image in such a manner that an input image coincides with an output image in accordance with the blur amount converted by the blur amount conversion section. 
     The value of the installation environment condition of the projector may include a value representing a lens condition of the projector. 
     The value representing the lens condition of the projector may include at least one of a zoom value, a shift value, or a focus value. 
     The value of the installation environment condition of the projector may include a value representing a position at which the projector is installed. 
     The value representing the installation position of the projector may include at least one of a distance of the projector to a projection plane, a pan of the projector, or a tilt of the projector. 
     The value of the installation environment condition of the projector may include a value representing an interior temperature of the projector. 
     The value of the installation environment condition of the projector may include information regarding a material of a projection plane of the projector. 
     The blur amount conversion section may convert the value of the installation environment condition of the projector into the amount of blur at the time of projection in reference to a blur amount database. 
     The blur amount database may be created beforehand. 
     The blur amount database may be created by model approximation of the blur amount using a predetermined parameter. 
     According to one aspect of the present technology, there is provided an image processing method including: by an image processing apparatus, converting a value of an installation environment condition representing a condition of an environment in which a projector is installed into an amount of blur at a time of projection; and generating a corrected image in such a manner that an input image coincides with an output image in accordance with the blur amount. 
     According to one aspect of the present technology, there is provided a program for causing a computer to function as: a blur amount conversion section configured to convert a value of an installation environment condition representing a condition of an environment in which a projector is installed into an amount of blur at a time of projection; and a corrected image generation section configured to generate a corrected image in such a manner that an input image coincides with an output image in accordance with the blur amount converted by the blur amount conversion section. 
     According to one aspect of the present technology, the values of the installation environment conditions representing the environment in which a projector is installed are converted into an amount of blur at the time of projection. A corrected image is then generated in such a manner that an input image coincides with an output image in accordance with the converted blur amount. 
     Advantageous Effects of Invention 
     According to the present technology, images can be processed. More particularly, the defocus blur can be easily corrected. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a block diagram depicting a first configuration example of a projector system to which the present technology is applied. 
         FIG. 2  is an explanatory diagram explaining a projector lens condition acquisition section. 
         FIG. 3  is an explanatory diagram explaining a defocus blur amount conversion section. 
         FIG. 4  is an explanatory diagram explaining model approximation involving simple parameters of the defocus blur amount. 
         FIG. 5  is a block diagram depicting a configuration example of a projector device in a case in which correction values are to be stored in a database. 
         FIG. 6  is another explanatory diagram explaining a defocus blur amount conversion section. 
         FIG. 7  is a flowchart explaining a defocus blur correction process performed by the projector system in  FIG. 1 . 
         FIG. 8  is a block diagram depicting a second configuration example of the projector system to which the present technology is applied. 
         FIG. 9  is a flowchart explaining a defocus blur correction process performed by the projector system in  FIG. 8 . 
         FIG. 10  is a block diagram depicting a third configuration example of the projector system to which the present technology is applied. 
         FIG. 11  is a flowchart explaining a defocus blur correction process performed by the projector system in  FIG. 10 . 
         FIG. 12  is a block diagram depicting a fourth configuration example of the projector system to which the present technology is applied. 
         FIG. 13  is a flowchart explaining a defocus blur correction process performed by the projector system in  FIG. 12 . 
         FIG. 14  is a block diagram depicting a principal configuration example of a computer. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Some embodiments for practicing the present technology (referred to as the embodiments) are described below. A description is given under the following headings: 
     0. Overview 
     1. First Embodiment 
     2. Second Embodiment 
     3. Third Embodiment 
     4. Fourth Embodiment 
     5. Computer 
     0. Overview 
     Video image display systems involving a projector are often subject to a defocus blur occurring in a video image displayed on a projection plane, the blur being caused primarily by a difference between light paths to a screen surface, diffusion of light thereon, and a performance of a lens used in the projector despite best efforts to focus on a plane screen. 
     There have been signal processing techniques for eliminating the defocus blur by estimating an amount thereof on the projection plane through inverse filtering computation using a camera and design values so as to project an image corrected by preliminary signal processing performed on the estimated amount of blur. 
     However, the technique for estimating a degree of blur using the design values such as an MTF drop amount (an amount of blur calculated from the design values of a projector lens) have resulted in deviations from the true values due to the conditions of the projector installation and the diffusion of light over the screen surface for example. Also, a measurement by a camera requires using a measuring system in a projector system. 
     Meanwhile, the degree of defocus blur varies with different conditions reflecting the environment in which the projector is installed (called the installation environment conditions hereunder), such as projector conditions (mainly lens parameters including zoom, shift, and focus values of the lens), projector installation position, projector interior temperature, and projection plane material. 
     According to the present technology, at least one of the projector installation conditions of the projector described above is acquired in real time, the acquired value being converted into the amount of blur at the time of projection before generating a corrected image. This provides easy correction of the defocus blur. 
     What follows is a specific description of the present technology. 
     1. First Embodiment 
     &lt;Configuration Examples of the Projector System&gt; 
       FIG. 1  is a block diagram depicting a first configuration example of a projector system to which the present technology is applied. 
     The projector system  1  in  FIG. 1  includes a projector device  11  and a screen (projection plane)  12 . The projector device  11  outputs onto the screen  12  a corrected image obtained by correcting an input image. The screen  12  displays the output image projected by the projector device  11 . 
     The projector device  11  includes a defocus blur correction signal processing section  21 , a defocus blur amount conversion section  22 , a database  23 , a projector lens condition acquisition section  24 , a projector  25 , and a remote controller  26 . The defocus blur correction signal processing section  21 , defocus blur amount conversion section  22 , database  23 , and projector lens condition acquisition section  24  are provided in an LSI. 
     The defocus blur correction signal processing section  21  generates the corrected image through signal processing in accordance with the amount of defocus blur from the defocus blur amount conversion section  22  in such a manner that the output image coincides with the input image. The defocus blur correction signal processing section  21  outputs the corrected image thus generated to the projector  25 . 
     In accordance with the values of the lens conditions from the projector lens condition acquisition section  24 , the defocus blur amount conversion section  22  references the database  23  and thereby sets an appropriate defocus blur amount. The defocus blur amount conversion section  22  supplies the defocus blur amount thus set to the defocus blur correction signal processing section  21 . 
     The database  23  has defocus blur amounts set therein. Multiple defocus blur amounts (spatial projection position and RGB) may be set in the database  23  with respect to a given lens condition value. Incidentally, the database  23  is created beforehand in a factory, for example. 
     The projector lens condition acquisition section  24  acquires numerically the current lens conditions (zoom/shift/focus) of the projector  25  in real time. The projector lens condition acquisition section  24  supplies the acquired lens condition values to the defocus blur amount conversion section  22 . 
     The projector  25  outputs (projects) the corrected image from the defocus blur correction signal processing section  21  onto the screen  12 . The lens conditions of the projector  25  are set by the remote controller  26 . The values of the lens conditions thus set are stored into an internal memory of the projector  25 . 
     The example in  FIG. 1  described above has the defocus blur correction signal processing section  21 , defocus blur amount conversion section  22 , database  23 , projector lens condition acquisition section  24 , and projector  25  configured in the same enclosure constituting the projector device  11 . Alternatively, part or all of the defocus blur correction signal processing section  21 , defocus blur amount conversion section  22 , database  23 , and projector lens condition acquisition section  24  may be configured in an enclosure different from the projector  25 . 
     &lt;Description of the Projector Lens Condition Acquisition Section&gt; 
     The projector lens condition acquisition section is explained next with reference to  FIG. 2 .  FIG. 2  depicts examples of defocus blur reflecting the lens shift conditions during oblique projection by a standard projector. 
       FIG. 2  illustrates defocus blur variations under different lens shift conditions, with an image at the lens center surrounded by defocused images incurred by upward lens shift, rightward lens shift, downward lens shift, and leftward lens shift. 
     As depicted in  FIG. 2 , it is clear that the defocus blur variations are great by angle and by intensity over the entire image. Whereas degrees of the variations are different, the amount of defocus blur varies similarly in terms of zoom and focus values. 
     The projector lens condition acquisition section  24  acquires numerically the projector lens conditions that vary in this manner. 
     &lt;Description of the Defocus Blur Amount Conversion Section&gt; 
     The defocus blur amount conversion section is described next with reference to  FIG. 3 . 
     For example, as indicated by A 1 , a camera  42  captures beforehand a measurement pattern  41  projected by the projector  25 . The capture provides measurements of the degrees of defocus blur corresponding to settable projector lens conditions (zoom value 1.0/shift value 1.0/focus value 1.0, . . . , zoom value val_zoom/shift value val_shift/focus value val_focus). 
     As indicated by A 2 , the degrees of defocus blur corresponding to the measured settable projector lens conditions are stored into the database  23 . It is to be noted that not all settable conditions but representative points alone may be measured and that the intervals between the measured representative points may be filled by linear interpolation at the time of image generation. 
     For example, the user uses the remote controller  26  to adjust the current projector lens conditions. As a result of this, the projector device  11  sets the current projector lens conditions. The projector lens condition acquisition section  24  acquires numerically the current projector lens conditions thus set. Consequently, as indicated by A 3 , the defocus blur amount conversion section  22  determines an appropriate degree of defocus blur by referencing the current projector lens conditions and the database  23 , and supplies the degree of defocus blur thus determined to the defocus blur correction signal processing section  21 . In turn, as indicated by A 4 , the defocus blur correction signal processing section  21  generates a corrected image reflecting the appropriate degree of defocus blur. 
     Incidentally, it is possible to reduce the database  23  in size through model approximation of the defocus blur amounts using simple parameters. For example, as depicted in  FIG. 4 , 66 types of the major axis of defocus blur σa: 0.0:0.2:2.0, of the minor axis of defocus blur σb: 0.0:0.2:2.0, and of the angle of defocus blur θ: −85:5:+90 may be stored only in combinations of their values into the database  23  created in an exhaustive manner. At the time of correcting an image, the degree of its defocus blur may be calculated from the values of σa, σp, and θ. 
     Alternatively, the database  23  may store not the degrees of defocus blur but the correction values from the start. In this case, as depicted in  FIG. 5 , the projector device  11  replaces the defocus blur amount conversion section  22  with a LUT creation section  61  that generates an LUT (Look Up Table) of projector lens condition values as well as σa, σb, and θ values. The created LUT is supplied to the defocus blur correction signal processing section  21 . Using the LUT, the defocus blur correction signal processing section  21  may obtain correction values from a database  62  in which the correction values are stored beforehand. The defocus blur correction signal processing section  21  may then proceed to correct the input image using the correction values thus obtained. 
     &lt;Description of the Defocus Blur Correction Signal Processing Section&gt; 
     The defocus blur amount conversion section is described next with reference to  FIG. 6 . 
     The defocus blur correction signal processing section  21  performs filter signal processing configured with a defocus blur inverse filter on the input image. Two design examples of the inverse filter are cited here: an inverse filter  81  designed by machine learning using an error value ε i =t i −y i , and an inverse filter  82  based on the Wiener Filter. The filters are not limited to the cited examples. 
     A design example of the inverse filter  81  by machine learning is defined by the following mathematical expression (1): 
                   [     Math   .           ⁢   1     ]                               y   i     =       ∑   k     ⁢       ω   k     ⁡     (       ∑   j     ⁢       w   j     ×     k   j         )           ⁢     
     ⁢       ɛ   i     =       t   i     -     y   i                 (   1   )               
where, t i  stands for a teacher, ω k  for defocus blur, and W j  for the filter to be designed.
 
     The inverse filter  82  based on the Wiener Filter is defined by the following mathematical expression (2): 
     
       
         
           
             
               
                 
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     The inverse filter  81  by machine learning is the more appropriate filter of the two. 
     The defocus blur correction signal processing section  21  uses the above-described inverse filter to perform the filter signal processing, thereby outputting an output image like the input image which is over-enhanced. The output image is projected onto the screen  12  via the projector  25 . At the time of projection onto the screen  12 , a defocus blur  71  is added in such a manner as to make the projected image the same as the input image. 
     &lt;Operation of the Projector System&gt; 
     Described next with reference to the flowchart of  FIG. 7  is a defocus blur correction process performed by the projector system  1  in  FIG. 1 . 
     For example, the user uses the remote controller  26  to adjust the current projector lens conditions. In accordance with signals from the remote controller  26 , the projector  25  in step S 21  sets the current projector lens conditions and stores the set conditions into an internal memory. 
     In step S 22 , the projector lens condition acquisition section  24  determines whether or not the setting is completed. If it is determined in step S 22  that the setting has yet to be completed, control is returned to step S 21 , and the subsequent steps are repeated. 
     If it is determined in step S 22  that the setting is completed, control is transferred to step S 23 . In step S 23 , the projector lens condition acquisition section  24  acquires the values of the projector lens conditions and supplies the acquired projector lens condition values to the defocus blur amount conversion section  22 . 
     In step S 24 , the defocus blur amount conversion section  22  references the database  23  to convert the projector lens condition values acquired in step S 22  into a defocus blur amount. The defocus blur amount conversion section  22  supplies the defocus blur amount obtained by conversion to the defocus blur correction signal processing section  21 . 
     In step S 25 , the defocus blur correction signal processing section  21  performs signal processing to correct the defocus blur amount obtained by conversion in step S 24  before generating the corrected image. The defocus blur correction signal processing section  21  outputs the corrected image thus generated to the projector  25 . 
     In step S 26 , the projector  25  projects the corrected image onto the screen  12 . 
     In the manner described above, the present technology permits easy correction of the defocus blur caused by the changing projector lens conditions. 
     2. Second Embodiment 
     &lt;Another Configuration Example of the Projector System&gt; 
       FIG. 8  is a block diagram depicting a second configuration example of the projector system to which the present technology is applied. 
     The projector system  1  in  FIG. 8  is configured basically similar to the projector system  1  in  FIG. 1 . The projector system  1  in  FIG. 8  thus includes a projector device  11  and a screen  12 . 
     Similar to the projector device  11  in  FIG. 1 , the projector device  11  in  FIG. 8  includes a defocus blur correction signal processing section  21 , a defocus blur amount conversion section  22 , a database  23 , and a projector  25 . The projector device  11  in  FIG. 8  differs from the projector device  11  in  FIG. 1  in that a projector installation condition acquisition section  101  replaces the projector lens condition acquisition section  24 . Although not illustrated, the remote controller  26  is assumed to be provided as in the case of  FIG. 1 . 
     That is, the projector installation condition acquisition section  101  acquires in real time the current installation conditions of the projector  25  (projection distance (DOLLY)/PAN/TILT)). The projector installation condition acquisition section  101  supplies the acquired values of the current installation conditions to the defocus blur amount conversion section  22 . 
     For example, the projection distance value is acquired from a ranging sensor attached to the projector  25 . The pan and tilt values are acquired from the projector  25  that has the function of obtaining keystone correction values. 
     Incidentally, the other installation conditions of the projector  25  (vertical position (PEDESTAL)/side-to-side positions (TRUCK)/(ROLL)) are not targeted for correction with this example. 
     In accordance with the installation condition values of the projector  25  from the projector installation condition acquisition section  101 , the defocus blur amount conversion section  22  references the database  23  and sets an appropriate amount of defocus blur accordingly. 
     &lt;Operation of the Projector System&gt; 
     Described next with reference to the flowchart of  FIG. 9  is the defocus blur correction process performed by the projector system  1  in  FIG. 8 . Steps S 44  to S 46  in  FIG. 9  are basically similar to step S 24  to S 26  in  FIG. 7 , and the explanations of these steps are omitted hereunder to avoid repetitiveness. 
     For example, the user uses the remote controller  26  to adjust the current installation conditions of the projector  25 . In accordance with signals from the remote controller  26 , the projector  25  in step S 41  sets the current installation conditions of the projector  25  and stores the set conditions into an internal memory. 
     In step S 42 , the projector installation condition acquisition section  101  determines whether or not the setting is completed. If it is determined in step S 42  that the setting has yet to be completed, control is returned to step S 41 , and the subsequent steps are repeated. 
     If it is determined in step S 42  that the setting is completed, control is transferred to step S 43 . In step S 43 , the projector installation condition acquisition section  101  acquires in real time the current installation conditions of the projector  25  (projection distance (DOLLY)/PAN/TILT)), and supplies the acquired values of the current installation conditions to the defocus blur amount conversion section  22 . 
     In the manner described above, the present technology permits easy correction of the defocus blur caused by the changing projector installation conditions. 
     3. Third Embodiment 
     &lt;Another Configuration Example of the Projector System&gt; 
       FIG. 10  is a block diagram depicting a third configuration example of the projector system to which the present technology is applied. 
     The projector system  1  in  FIG. 10  is configured basically similar to the projector system  1  in  FIG. 1 . The projector system  1  in  FIG. 10  thus includes a projector device  11  and a screen  12 . 
     Similar to the projector device  11  in  FIG. 1 , the projector device  11  in  FIG. 10  includes a defocus blur correction signal processing section  21 , a defocus blur amount conversion section  22 , a database  23 , and a projector  25 . The projector device  11  in  FIG. 10  differs from the projector device  11  in  FIG. 1  in that a projector interior temperature acquisition section  111  replaces the projector lens condition acquisition section  24 . In the example of  FIG. 10 , the projector  25  has an internal timer  112 . Although not illustrated, the remote controller  26  is assumed to be provided as in the case of  FIG. 1 . 
     That is, the temperature of the projector  25  tends to be the highest when power is first turned on and to approach an ideal value gradually thereafter. The glass lens of the projector  25  varies in its degree of defocus blur depending on temperature characteristics. Thus, the projector interior temperature acquisition section  111  acquires in real time the current interior temperature of the projector  25  and supplies the acquired interior temperature value to the defocus blur amount conversion section  22 . For example, the projector  25  measures time by means of the internal timer  112 . Upon elapse of a predetermined time period, the defocus blur correction process is carried out. Although the defocus blur correction process is described here as being performed upon elapse of the predetermined time period, for example, this process may alternatively be carried out immediately after power-on. 
     In accordance with the interior temperature value of the projector  25  from the projector interior temperature acquisition section  111 , the defocus blur amount conversion section  22  references the database  23  and sets an appropriate defocus blur amount accordingly. 
     &lt;Operation of the Projector System&gt; 
     Described next with reference to the flowchart of  FIG. 11  is the defocus blur correction process performed by the projector system  1  in  FIG. 10 . Steps S 63  to S 65  in  FIG. 11  are basically similar to step S 24  to S 26  in  FIG. 7 , and the descriptions of these steps are omitted hereunder to avoid repetitiveness. 
     For example, after power in the remote controller  26  is turned on, the projector  25  waits for a predetermined time period to elapse in step S 61 . 
     If it is determined in step S 61  that the predetermined time period has elapsed, control is transferred to step S 62 . In step S 62 , the projector interior temperature acquisition section  111  acquires in real time the value of the current interior temperature of the projector  25 , and supplies the acquired value of the current interior temperature to the defocus blur amount conversion section  22 . 
     In the manner described above, the present technology permits easy correction of the defocus blur caused by the changing projector interior temperature. 
     4. Fourth Embodiment 
     &lt;Another Configuration Example of the Projector System&gt; 
       FIG. 12  is a block diagram depicting a fourth configuration example of the projector system to which the present technology is applied. 
     The projector system  1  in  FIG. 12  is configured basically similar to the projector system  1  in  FIG. 1 . The projector system  1  in  FIG. 12  thus includes a projector device  11  and a screen  12 . 
     Similar to the projector device  11  in  FIG. 1 , the projector device  11  in  FIG. 12  includes a defocus blur correction signal processing section  21 , a defocus blur amount conversion section  22 , a database  23 , and a projector  25 . The projector device  11  in  FIG. 12  differs from the projector device  11  in  FIG. 1  in that a screen material acquisition section  121  replaces the projector lens condition acquisition section  24 . Although not illustrated, the remote controller  26  is assumed to be provided as in the case of  FIG. 1 . 
     That is, the screen material is set to the projector  25  by means of a UI (User Interface) or the remote controller  26 . The degree of defocus blur varies with the screen material as well. The screen materials include glass screens and directional screens. Specifically, some of the screen materials are: 150 PROG Advance screen, bead screen, White Matte Advance screen, White Matte screen, SnoMatte screen, and Magnet Sufton screen. The screen material acquisition section  121  acquires in real time the information regarding the screen material from the projector  25 , and supplies the acquired screen material information to the defocus blur amount conversion section  22 . 
     In accordance with the screen material information from the screen material acquisition section  121 , the defocus blur amount conversion section  22  references the database  23  and sets an appropriate defocus blur amount accordingly. 
     &lt;Operation of the Projector System&gt; 
     Described next with reference to the flowchart of  FIG. 13  is the defocus blur correction process performed by the projector system  1  in  FIG. 12 . Steps S 84  to S 86  in  FIG. 13  are basically similar to step S 24  to S 26  in  FIG. 7 , and the descriptions of these steps are omitted hereunder to avoid repetitiveness. 
     For example, the user uses the remote controller  26  to set the current screen material for the projector  25 . In accordance with signals from the remote controller  26 , the projector  25  in step S 81  sets the current screen material and stores the set screen material into an internal memory. 
     In S 82 , the screen material acquisition section  121  determines whether or not the setting is completed. If it is determined in step S 82  that the setting has yet to be completed, control is returned to step S 81 , and the subsequent steps are repeated. 
     If it is determined in step S 82  that the setting is completed, control is transferred to step S 83 . In step S 83 , the screen material acquisition section  121  acquires in real time the information regarding the current screen material, and supplies the acquired screen material information to the defocus blur amount conversion section  22 . 
     In the manner described above, the present technology permits easy correction of the defocus blur caused by the changing screen materials for the projector. 
     Incidentally, whereas the functions of the first through the fourth embodiments have been discussed separately, these functions may be combined in part or in total in a single device. 
     According to the present technology described above, the image display system involving the projector is configured to correct, through image processing, the defocus blur generated on the projection plane despite the best efforts to focus thereon. 
     In the case where defocus blur is to be corrected, it is necessary to estimate the amount of the defocus blur. According to the present technology, the information regarding the environment in which the projector is installed (projector lens conditions, projector installation conditions, projector temperature, and screen material) is acquired. The values from the acquired information are then converted into the defocus blur amount. This makes it possible to correct the blur easily without recourse to a measuring system or a complicated UI. 
     The use of a simple UI also permits correction of the defocus blur that varies with the screen material. 
     The present technology can be applied to home-use projectors, business-use projectors, and projector products in general. 
     5. Fifth Embodiment 
     &lt;Computer&gt; 
     The series of steps and processes described above may be executed either by hardware or by software. Where the series of steps or processes is to be carried out by software, the programs constituting the software are installed into a suitable computer. Variations of the computer include one with the software preinstalled in its dedicated hardware, and a general-purpose personal computer or like equipment capable of executing diverse functions by the programs installed therein. 
       FIG. 14  is a block diagram depicting a hardware configuration example of a computer that executes the above-described series of processing using programs. 
     In a computer  200  depicted in  FIG. 14 , a CPU (Central Processing Unit)  201 , a ROM (Read Only Memory)  202 , and a RAM (Random Access Memory)  203  are interconnected via a bus  204 . 
     The bus  204  is also connected with an input/output interface  210 . The input/output interface  210  is connected with an input section  211 , an output section  212 , a storage section  213 , a communication section  214 , and a drive  215 , for example. 
     The input section  211  includes a keyboard, a mouse, a microphone, a touch panel, and input terminals, for example. The output section  212  includes a display, speakers, and output terminals for example. The storage section  213  includes a hard disk, a RAM disk, and a nonvolatile memory, for example. The communication section  214  includes a network interface, for example. The drive  215  drives a removable medium  221  such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory. 
     In the computer configured as described above, the CPU  201  performs the above-mentioned series of processing by loading appropriate programs from the storage section  213  into the RAM  203  via the input/output interface  210  and the bus  204  and by executing the loaded programs. As needed, the RAM  203  may store data necessary for the CPU  201  to execute diverse processes. 
     The programs to be executed by the computer (CPU  201 ) may be recorded on the removable medium  221  serving as a package medium when offered for use. In this case, the programs may be installed into the storage section  213  via the input/output interface  210  from the removable medium  221  attached to the drive  215 . 
     Alternatively, the programs may be offered for use via a wired or wireless communication medium such as local area networks, the Internet, and digital satellite broadcasts. In such cases, the programs may be received by the communication section  214  before being installed into the storage section  213 . 
     As another alternative, the programs may be preinstalled in the ROM  202  or in the storage section  213 . 
     The embodiments of the present technology are not limited to those discussed above. The embodiments may be modified or altered in diverse fashion within the scope and spirit of the present technology. 
     For example, in this specification, the term “system” refers to an aggregate of multiple components (e.g., devices or modules (parts)). It does not matter whether or not all components are housed in the same enclosure. Thus, a system may be configured with multiple devices housed in separate enclosures and interconnected via a network, or with a single device that houses multiple modules in a single enclosure. 
     As another example, any configuration described above as one device (or processing section) may be divided into multiple devices (or processing sections). Conversely, the configurations described above as multiple devices (or processing sections) may be unified into one device (or processing section). Also, the configuration of each device (or processing section) may obviously be supplemented with a configuration or configurations other than those discussed above. Furthermore, part of the configuration of a device (or processing section) may be included in the configuration of another device (or processing section), provided the configuration and the operations remain substantially the same for the system as a whole. 
     As a further example, the present technology may be implemented as a cloud computing setup in which a single function is processed cooperatively by multiple networked devices on a shared basis. 
     As a still further example, the above-described programs may be executed by any device. In such a case, the device may be configured to have necessary functions (e.g., functional blocks) and be provided with necessary information. 
     As a yet further example, each of the steps discussed in reference to the above-described flowcharts may be executed either by a single device or by multiple devices on a shared basis. Furthermore, if a single step includes multiple processes, these processes may be executed either by a single device or by multiple devices on a shared basis. 
     Also, the programs to be executed by the computer may each be processed chronologically, i.e., in the sequence depicted in this specification, in parallel with other programs, or in otherwise appropriately timed fashion such as when the program is invoked as needed. Furthermore, the processes of the steps describing a given program may be performed in parallel with, or in combination with, the processes of other programs. 
     The multiple elements of the present technology described in this specification may be implemented independently of each other, as long as there occurs no conflict therebetween. Obviously, any multiple elements of the present technology may be implemented in combination. For example, the elements of the present technology discussed in connection with one embodiment may be implemented in combination with the elements of the present technology described in conjunction with another embodiment. Furthermore, any elements of the above-described present technology may be implemented in combination with techniques not discussed above. 
     The present disclosure may be implemented preferably in the following configurations: 
     (1) An image processing apparatus including: 
     a blur amount conversion section configured to convert a value of an installation environment condition representing a condition of an environment in which a projector is installed into an amount of blur at a time of projection; and 
     a corrected image generation section configured to generate a corrected image in such a manner that an input image coincides with an output image in accordance with the blur amount converted by the blur amount conversion section. 
     (2) The image processing apparatus as stated in paragraph (1) above, in which the value of the installation environment condition of the projector includes a value representing a lens condition of the projector. 
     (3) The image processing apparatus as stated in paragraph (2) above, in which the value representing the lens condition of the projector includes at least one of a zoom value, a shift value, or a focus value. 
     (4) The image processing apparatus as stated in paragraph (1) above, in which the value of the installation environment condition of the projector includes a value representing a position at which the projector is installed. 
     (5) The image processing apparatus as stated in paragraph (4) above, in which the value representing the installation position of the projector includes at least one of a distance of the projector to a projection plane, a pan of the projector, or a tilt of the projector. 
     (6) The image processing apparatus as stated in paragraph (1) above, in which the value of the installation environment condition of the projector includes a value representing an interior temperature of the projector. 
     (7) The image processing apparatus as stated in paragraph (1) above, in which the value of the installation environment condition of the projector includes information regarding a material of a projection plane of the projector. 
     (8) The image processing apparatus as stated in any one of paragraphs (1) to (7) above, in which the blur amount conversion section converts the value of the installation environment condition of the projector into the amount of blur at the time of projection in reference to a blur amount database. 
     (9) The image processing apparatus as stated in paragraph (8) above, in which the blur amount database is created beforehand. 
     (10) The image processing apparatus as stated in paragraph (8) or (9) above, in which the blur amount database is created by model approximation of the blur amount using a predetermined parameter. 
     (11) An image processing method including: 
     by an image processing apparatus,
         converting a value of an installation environment condition representing a condition of an environment in which a projector is installed into an amount of blur at a time of projection; and   generating a corrected image in such a manner that an input image coincides with an output image in accordance with the blur amount.       

     (12) A program for causing a computer to function as: 
     a blur amount conversion section configured to convert a value of an installation environment condition representing a condition of an environment in which a projector is installed into an amount of blur at a time of projection; and 
     a corrected image generation section configured to generate a corrected image in such a manner that an input image coincides with an output image in accordance with the blur amount converted by the blur amount conversion section. 
     REFERENCE SIGNS LIST 
       1  Projector system,  11  Projector device,  12  Screen,  21  Defocus blur correction signal processing section,  22  Defocus blur amount conversion section,  23  Database,  24  Projector lens condition acquisition section,  25  Projector,  26  Remote controller,  101  Projector installation condition acquisition section,  111  Projector interior temperature acquisition section,  112  Timer,  121  Screen material acquisition section