Information processing apparatus and control method

1. An information processing apparatus comprising:

an imaging unit having an image sensor that detects a first plurality of pieces of pixel information, the imaging unit generates an image that is made up of the first plurality of pieces of pixel information detected by the image sensor;

an image processor that detects whether a user is present or not in a predetermined detection range, based on an image that is made up of a second plurality of pieces of pixel information detected by the image sensor; and

an operation control unit that, when the image processor detects the user in the predetermined detection range, cancels a standby state wherein some functions of a system of the information processing apparatus stops,

wherein

in the standby state, the imaging unit increases at least one of a resolution and a frame rate, in a stepwise manner, to detect the first plurality of pieces of pixel information;

in the standby state, the image processor detects an object in the predetermined detection range based on an image of a first condition having a first resolution and a first frame rate;

in the standby state, after the image processor detects the object in the predetermined detection range, the image processor detects whether the user is present or not in the predetermined detection range based on an image of a second condition having at least one of a second resolution and a second frame rate that is higher than the first resolution and the first frame rate of the first condition;

in the standby state, the image processor detects the object at a first stage based on a first image having the first resolution obtained by removing some pieces of pixel information from an overall range of the image sensor and detected at the first frame rate,

in the standby state, after the object is detected at the first stage, the image processor at a second stage detects whether the object detected at the first stage includes a human face or not based on a second image having the second resolution higher than the first resolution and detected at the second frame rate higher than the first frame rate, and

in the standby state, after the human face is detected at the second stage, the image processor at a third stage detects a distance from the imaging unit to the human face detected at the second stage based on a third image having a third resolution higher than the second resolution and detected at a third frame rate higher than the second frame rate to detect whether the user is present in the predetermined detection range or not.

2. The information processing apparatus according to claim 1 , wherein the imaging unit includes the image processor, and

when presence of the user is detected in the standby state, the image processor functions as a complex device having multi-functions, and outputs a cancel request to request cancel of the standby state through an interface of a device class that is different from a device class to output an image made up of the first plurality of pieces of pixel information.

3. The information processing apparatus according to claim 2 , wherein the image processor outputs the cancel request through an HID (Human Interface Device) device class of a USB (Universal Serial Bus) interface.

4. The information processing apparatus according to claim 1 , wherein, when a detection target is detected in the predetermined detection range, the image processor narrows a range into a partial range including the detection target and increases resolution of the partial range.

5. The information processing apparatus according to claim 1 , wherein the image processor periodically detects whether the user is present or not in the predetermined detection range in a normal operating state after cancelling the standby state, and

in the normal operating state, when the image processor does not detect presence of the user in the predetermined detection range, the operation control unit controls to transition the system from the normal operating state to the standby state.

6. The information processing apparatus according to claim 5 , wherein, in the normal operating state, the imaging unit increases at least one of another resolution and another frame rate in a stepwise manner to detect the first plurality of pieces of pixel information.

7. The information processing apparatus according to claim 5 , wherein the image processor in the normal operating state detects whether the user is present or not in the predetermined detection range, based on an image having at least one of another resolution and another frame rate that increases in a stepwise manner, the detection being based on at least one of a face position, a face direction, and a line of sight of the user.

8. A control method for an information processing apparatus including an imaging unit having an image sensor that detects a first plurality of pieces of pixel information, the imaging unit generates an image that is made up of the first plurality of pieces of pixel information detected by the image sensor, the method comprising:

a detection step wherein the imaging unit is in a standby state wherein some function of a system of the information processing apparatus stops, and the imaging unit increases at least one of a resolution and a frame rate in a stepwise manner to detect the first plurality of pieces of pixel information;

an image processing step wherein an image processor detects whether a user is present or not in a predetermined detection range based on an image made up of a second plurality of pieces of pixel information detected at the detection step; and

an operation control step wherein, when the image processing step detects the user in the predetermined range, an operation control unit cancels the standby state;

in the standby state, the image processor detects an object in the predetermined detection range based on an image of a first condition having a first resolution and a first frame rate;

in the standby state, after the image processor detects the object in the predetermined detection range, the image processor detects whether the user is present or not in the predetermined detection range based on an image of a second condition having at least one of a second resolution and a second frame rate that is higher than the first resolution and the first frame rate of the first condition;

in the standby state, the image processor detects the object at a first stage based on a first image having the first resolution obtained by removing some pieces of pixel information from an overall range of the image sensor and detected at the first frame rate,

in the standby state, after the object is detected at the first stage, the image processor at a second stage detects whether the object detected at the first stage includes a human face or not based on a second image having the second resolution higher than the first resolution and detected at the second frame rate higher than the first frame rate, and

in the standby state, after the human face is detected at the second stage, the image processor at a third stage detects a distance from the imaging unit to the human face detected at the second stage based on a third image having a third resolution higher than the second resolution and detected at a third frame rate higher than the second frame rate to detect whether the user is present in the predetermined detection range or not.