This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2011-78559, filed on Mar. 31, 2011, the entire contents of which are incorporated herein by reference.
Embodiments described herein relate to an information processing apparatus and method.
A user often views a display of an information terminal such as a mobile phone or smartphone while walking. Therefore, due to a shake of the user or the terminal, the user may have difficulty of viewing the display.
Therefore, there is known a method in which the shake of the terminal is detected by an acceleration sensor, and a position of the user's face is identified through analysis of a camera image, to correct a displayed position of an image on the display according to a relative shake of the terminal with respect to the position of the face.
In this method, however, continuous analysis of the camera image increases power consumption of the terminal, resulting in a reduction in usable time of the terminal. In addition, in this method, a provision of means of identifying the position of the face on the terminal increases a fabrication cost of the terminal.
Embodiments will now be explained with reference to the accompanying drawings.
An embodiment described herein is an information processing apparatus including an acceleration sensor configured to detect acceleration of the information processing apparatus, and a display part configured to include a screen for displaying an image. The apparatus further includes a determination part configured to determine whether a displayed position of the image is to be corrected, based on duration of a state in which the acceleration occurs in a predetermined direction. The apparatus further includes a correction part configured to correct the displayed position of the image according to the determination made by the determination part.
Another embodiment described herein is an information processing method including displaying an image on a screen of an information processing apparatus, and detecting acceleration of the information processing apparatus. The method further includes determining whether a displayed position of the image is to be corrected, based on duration of a state in which the acceleration occurs in a predetermined direction. The method further includes correcting the displayed position of the image according to the determination.
The information terminal in
In addition, the information terminal in
As shown in
Arrows α and β shown in
When the power to the information terminal of the present embodiment is turned on, the information terminal displays an image on the screen 23, and starts detection of accelerations by the acceleration sensor 1 (step S1). Specifically, the acceleration sensor 1 detects the accelerations of the information terminal in the α, β and γ directions. The detection of the accelerations by the acceleration sensor 1 is continuously performed. The accelerations detected by the acceleration sensor 1 are output to the CPU 2 as electrical signals.
Then, the CPU 2 checks an acceleration state of the information terminal from the electrical signals. Specifically, the CPU 2 checks whether upward acceleration continuously occurs. As will be described later, it is possible to estimate, from such upward acceleration, whether the information terminal is shaking relative to a user's head.
When the upward acceleration continuously occurs, it is estimated that the information terminal is shaking relative to the user's head. Therefore, in this case, the CPU 2 determines to correct the displayed position of the image on the screen 23 (step S2). Then, the CPU 2 corrects the displayed position of the image on the screen 23 (step S3). At this time, the displayed position of the image is corrected in an opposite direction of that of the shake so as to cancel out the relative shake.
On the other hand, when the upward acceleration does not continuously occur, it is estimated that the shake of the information terminal is synchronized with the shake of the user's head. Therefore, in this case, the CPU 2 determines not to correct the displayed position of the image on the screen 23 (step S2).
Note that the functions of performing steps S2 and S3 are implemented by performing a program on the CPU 2. The functions of performing steps S2 and S3 are examples of a determination part and a correction part of the disclosure, respectively.
(1) Details of Steps S2 and S3
Next, the details of the processes at steps S2 and S3 will be described with reference to
In
In general, the movement of the head H and the movement of the information terminal T are not completely synchronized with each other and subtly differ from each other. The difference in movement between the head H and the information terminal T increases when a user's foot lands.
An arrow “A” in
On the other hand,
In
In general, the sinking times Δt1 and Δt2 and the amounts of sinking ΔZ1 and ΔZ2 change according to the weight of the information terminal. When the information terminal is light, the sinking time is short and the amount of sinking is small, and accordingly, the movement of the information terminal is a movement substantially synchronized with the movement of the head. On the other hand, when the information terminal is heavy, the sinking time is long and the amount of sinking is large, and accordingly, sinking of the information terminal at landing is remarkable. The difference between the above-described two cases will be described with reference to
The acceleration of the information terminal upon walking is downward acceleration which is close to the gravitational acceleration at free fall. However, the acceleration of the information terminal upon walking turns into upward acceleration when the user's foot lands (see
However, the value and duration of the upward acceleration at landing change according to the weight of the information terminal.
The reason that such a difference is observed in the upward acceleration az according to the weight of the information terminal will be described below.
When the user's foot lands, velocity of the information terminal changes from downward velocity to upward velocity due to a force acting on the information terminal through the user's hand.
At this time, when the information terminal is light, by applying a force only for a moment, the velocity of the information terminal changes from the downward velocity to the upward velocity. Therefore, when the information terminal is light, momentary high acceleration occurs as the upward acceleration az at landing (
On the other hand, when the information terminal is heavy, the velocity of the information terminal does not change from the downward velocity to the upward velocity unless a force is continuously applied. Therefore, when the information terminal is heavy, continuous low acceleration occurs as the upward acceleration az at landing (
Accordingly, a relative shake between the user's head and the information terminal can be estimated from the upward acceleration az of the information terminal. When momentary acceleration occurs as the acceleration az, it is estimated that the shake of the information terminal is synchronized with the shake of the head. On the other hand, when continuous acceleration occurs as the acceleration az, it is estimated that a relative shake between the user's head and the information terminal occurs.
Therefore, when the CPU 2 obtains the accelerations in the α, β and γ directions from the acceleration sensor 1, the CPU 2 calculates the acceleration in the Z direction (i.e., upward acceleration) az from these accelerations. Then, the CPU 2 checks whether the upward acceleration az occurs continuously. The CPU 2 then determines whether the displayed position of the image on the screen 23 is to be corrected, based on the duration of a state in which the upward acceleration az occurs (step S2:
For example, when the above-described duration is greater than or equal to a threshold value, the CPU 2 determines to correct the displayed position of the image (step S2). Then, the CPU 2 corrects the displayed position of the image on the screen 23 (step S3). At this time, the displayed position of the image is corrected in a direction opposite to the direction of the shake so as to cancel out the relative shake between the user's head and the information terminal.
On the other hand, when the above-described duration is less than the threshold value, the CPU 2 determines not to correct the displayed position of the image (step S2).
As described above, in the present embodiment, a determination as to whether to correct the displayed position of the image on the screen 23 is made based on the duration of a state in which the upward acceleration az occurs. Therefore, in the present embodiment, the correction of the displayed position against the shake can be made based on the results of detection of the accelerations by the acceleration sensor 1, without through analysis of a camera image and the like. Therefore, according to the present embodiment, the correction of the displayed position against the shake can be made while suppressing an increase in the power consumption of the information terminal.
Note that a relationship between the timing at which the above-described duration is detected and the timing at which this detection result is reflected in correction may be set in any manner.
For example, the duration during which a single sinking continues (Δt1 or Δt2) may be detected, and when the duration is greater than or equal to a threshold value, the displayed position may be corrected at next sinking. This is effective, for example, for the case in which there are a few variations in sinking time or the amount of sinking at each sinking.
Alternatively, the upward acceleration az may be analyzed every fixed cycle, and when a state in which the upward acceleration az occurs continues during a single cycle, the displayed position may be corrected in the next cycle. This is effective, for example, for the case in which there are many variations in sinking time or the amount of sinking at each sinking.
(2) Correction Amount of Displayed Position
Next, the correction amount of the displayed position will be described with reference to
In the present embodiment, when it is determined to correct the displayed position of the image, as shown in
Reference character D shown in
A method of determining the correction amount D of the displayed position will be described below with reference to
In
On the other hand, when the acceleration az decreases during a fixed period of time (Δaz<0), the correction amount D is then reduced immediately (ΔD<0). Specifically, when the acceleration az decreases, the correction amount D is reduced to D+ΔD, and the displayed position of the image is moved in a −β direction.
According to such displayed position correction, as shown in
Note that although, in
Alternatively, the correction amount D may be determined based on the value of sinking time (Δt1 or Δt2). For example, the correction amount D is set to a larger value as the sinking time increases. This is effective, for example, for the case in which a determination as to whether to correct the displayed position is made based on the sinking time.
Alternatively, the correction amount D may be changed according to an inclination of the information terminal. Such displayed position correction will be described below with reference to
In
Note that although, in
As described above, in the present embodiment, a determination as to whether to correct the displayed position of the image on the screen 23 is made based on the duration of a state in which the upward acceleration az occurs. Therefore, in the present embodiment, the correction of the displayed position against the shake can be made based on the results of detection of the accelerations by the acceleration sensor 1, without through analysis of a camera image and the like. Therefore, according to the present embodiment, the correction of the displayed position against the shake can be made while suppressing an increase in the power consumption of the information terminal.
A second embodiment which is a modification of the first embodiment will be described below mainly on differences from the first embodiment.
A curve CT shown in
On the other hand, a curve CH represents the change in position of the user's head in the Z direction. The change in position of the head in the Z direction can be estimated from the change in position of the information terminal in the Z direction. A method of estimating the change in position of the head and a method of using a result of the estimation will be described below with reference to
In the present embodiment, by a configuration shown in
In the present embodiment, the configuration shown in
A method of estimating the change in position of the head and a method of using a result of the estimation which are performed by the blocks 41 to 44 will be described below.
When estimating the change in position of the head at given sinking, the reaching point estimating part 42 estimates the maximum reaching point Zmax and minimum reaching point Zmin of the change in position of the head (see
Specifically, the reaching point estimating part 42 estimates the reaching time of the maximum reaching point Zmax, the reaching time of the minimum reaching point Zmin, and a difference in Z-coordinate between the maximum reaching point Zmax and the minimum reaching point Zmin.
The reaching time of the minimum reaching point Zmin can be estimated as the start time t1 of the sinking of the information terminal (
The position change estimating part 43 then estimates the change in position of the head, based on the maximum reaching point Zmax and the minimum reaching point Zmin. As shown in
The interpolation process may be performed using other curves than the parabolic line and the straight line. The change in position of the head may be estimated by a comparison process with actual measurement data, instead of the interpolation process. The estimation by the comparison process can be implemented, for example, by preparing a plurality of samples of actual measurement data of the change in position of the head, selecting a sample closest to the maximum reaching point Zmax and the minimum reaching point Zmin estimated by the reaching point estimating part 42, and using the selected sample as a result of the estimation of the change in position of the head.
The correction amount determining part 44 then determines the correction amount of the displayed position of the image, based on the calculation result of the change in position of the information terminal and the estimation result of the change in position of the head. Specifically, the correction amount determining part 44 determines the correction amount of the displayed position, based on the difference between the change in position of the information terminal and the change in position of the head. Therefore, in the present embodiment, even when the amount of sinking ΔZT of the information terminal is large and accordingly the sinking of the information terminal continues over a long period of time, the displayed position correction with high accuracy can be performed.
As described above, in the present embodiment, the change in position of the information terminal is calculated, the change in position of the head is estimated, and then the correction amount of the displayed position of the image is determined based on the result of the calculation of the change in position of the information terminal and the result of the estimation of the change in position of the head. Therefore, even when the amount of sinking ΔZT of the information terminal is large and accordingly the sinking of the information terminal continues over a long period of time, the displayed position correction with high accuracy can be performed.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel apparatuses and methods described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the apparatuses and methods described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.
Number | Date | Country | Kind |
---|---|---|---|
2011-078559 | Mar 2011 | JP | national |