JP2013115702A5 - IMAGING DEVICE AND IMAGING DEVICE CONTROL METHOD - Google Patents

Description

The present invention relates to an imaging apparatus and a method for controlling the imaging apparatus , and more particularly to a technique for reducing the degree and frequency of image quality degradation at the periphery of an image due to luminance shading correction.

First imaging apparatus according to the present invention is imaged with an imaging device for converting a lens for focusing light from an object, a more focused light Gakuzo the lens into an electric signal, to the image sensor Light shielding means for controlling light transmission / shielding of light, signal processing means for converting an electric signal output from the image sensor into image data, and luminance shading correction for the image data converted by the signal processing means A light-shielded image in a state where the light is shielded by the light-shielding means, a calculation value indicating a dark current unevenness amount is obtained from the image data of the obtained light-shielded image, and the correction means performs the luminance shading correction. And a control means for determining a correction amount to be used based on the magnitude of the calculation value.

Second imaging apparatus according to the present invention is imaged with an imaging device for converting a lens for focusing light from an object, a more focused light Gakuzo the lens into an electric signal, to the image sensor Light shielding means for controlling light transmission / shielding of light, signal processing means for converting an electric signal output from the image sensor into image data, and luminance shading correction for the image data converted by the signal processing means and correcting means for performing, before Symbol correcting means, characterized in that it comprises a control means for determining, based on shooting conditions at the time of photographing the correction amount used for the luminance shading correction.

Claims (18)

A lens for imaging light from the subject;
An image sensor for converting a more focused light Gakuzo the lens into an electric signal,
A light shielding means for controlling light transmission / light shielding of light imaged on the image sensor;
Signal processing means for converting an electrical signal output from the image sensor into image data;
Correction means for performing luminance shading correction on the image data converted by the signal processing means;
A light-shielded image is captured in a state where the light is shielded by the light-shielding means, a calculation value indicating a dark current unevenness amount is obtained from the image data of the obtained light-shielded image, and the correction amount used by the correction means for the luminance shading correction is calculated based on the calculation. An image pickup apparatus comprising: control means for determining based on the magnitude of the value. The control means divides the image data of the light-shielded image into a plurality of areas, obtains the calculated value for each area, and the position in the recording pixel area of the imaging element corresponding to the area with the largest calculated value and the based on the magnitude of the operation value, the imaging apparatus according to claim 1, characterized in that to determine the correction amount. The imaging apparatus according to claim 2 , wherein the control unit divides the image data of the light-shielded image into m × n regions where m and n are natural numbers. Wherein, among the plurality of regions, when the calculated value is the largest region located at the periphery of the recording pixel area of the imaging device, recording the largest area the calculated value of the imaging device the imaging apparatus according to claim 2 or 3, characterized in that setting a small pre SL correction amount than when positioned at the center of the pixel region.   The control means refers to a table in which the correction amount is determined based on a relationship between the magnitude of the calculated value and the position in the recording pixel region of the imaging element corresponding to each of the plurality of regions, thereby determining the correction amount. The imaging device according to claim 2, wherein the imaging device is determined. A lens for imaging light from the subject;
An image sensor for converting a more focused light Gakuzo the lens into an electric signal,
A light shielding means for controlling light transmission / light shielding of light imaged on the image sensor;
Signal processing means for converting an electrical signal output from the image sensor into image data;
Correction means for performing luminance shading correction on the image data converted by the signal processing means;
Before SL correcting means imaging apparatus, wherein a and a control means for determining, based on shooting conditions at the time of photographing the correction amount used for the luminance shading correction. The imaging apparatus according to claim 6 , wherein the imaging condition includes at least one of an ambient temperature of the imaging element, a shutter speed, and ISO sensitivity at the time of imaging the subject. The control means, in accordance with the ambient temperature increases, also in accordance with the shutter speed becomes slower, also in accordance with the ISO sensitivity is high, according to claim 7, characterized in that to set the correction amount smaller Imaging device. The control unit determines the correction amount by referring to a table in which the correction amount is determined based on at least two relationships among an ambient temperature of the image sensor, the shutter speed, and the ISO sensitivity. Item 9. The imaging device according to Item 7 or 8. An imaging device control method for converting an optical image into an electrical signal by an imaging device and converting an electrical signal output from the imaging device into image data,
A photographing step of photographing a light-shielded image in a light-shielded state by a light-shielding means for controlling light transmission / shielding of light imaged on the image sensor;
A calculation step for obtaining a calculation value indicating a dark current unevenness amount from the image data of the light-shielded image obtained in the photographing step;
A determining step for determining a correction amount used for luminance shading correction based on the magnitude of the calculated value obtained in the calculating step;
And a correction step for performing luminance shading correction on the image data based on the correction amount determined in the determination step. In the determining step, the image data of the light-shielded image is divided into a plurality of areas, the calculated values are obtained for each area, the position in the recording pixel area of the imaging element corresponding to the area with the largest calculated value, and the The method of controlling an imaging apparatus according to claim 10, wherein the correction amount is determined based on a magnitude of a calculation value. 12. The method according to claim 11, wherein in the determining step, the image data of the light-shielded image is divided into m × n regions, where m and n are natural numbers. In the determining step, when the region having the largest calculated value among the plurality of regions is located in the periphery of the recording pixel region of the image sensor, the region having the largest calculated value is the recording pixel of the image sensor. The method of controlling an imaging apparatus according to claim 11 or 12, wherein the correction amount is set to be smaller than a case where the correction amount is located in a central portion of the region. In the determining step, the correction amount is determined by referring to a table in which the correction amount is determined based on the relationship between the magnitude of the calculated value and the position in the recording pixel region of the imaging element corresponding to each of the plurality of regions. The method for controlling an imaging apparatus according to claim 11, wherein the control method is determined. An imaging device control method for converting an optical image into an electrical signal by an imaging device and converting an electrical signal output from the imaging device into image data,
A photographing step of photographing a light-shielded image in a light-shielded state by a light-shielding means for controlling light transmission / shielding of light imaged on the image sensor;
A calculation step for obtaining a calculation value indicating a dark current unevenness amount from the image data of the light-shielded image obtained in the photographing step;
A determination step for determining a correction amount used for luminance shading correction based on shooting conditions at the time of shooting;
And a correction step for performing luminance shading correction on the image data based on the correction amount determined in the determination step.
An image pickup apparatus control method comprising: 16. The method of controlling an imaging apparatus according to claim 15, wherein the imaging condition includes at least one of an ambient temperature of the imaging element, a shutter speed, and ISO sensitivity at the time of imaging. 17. The determination step according to claim 16, wherein in the determination step, the correction amount is set to be smaller as the ambient temperature becomes higher, as the shutter speed becomes slower, and as the ISO sensitivity becomes higher. Method for controlling the imaging apparatus. The determination step includes determining the correction amount by referring to a table in which the correction amount is determined based on at least two relationships among the ambient temperature of the image sensor, the shutter speed, and the ISO sensitivity. Item 18. A method for controlling an imaging apparatus according to Item 16 or 17.