TWI290662B - Digital camera automatic white balance method and apparatus - Google Patents

Abstract

A digital camera automatic white balance method and apparatus is to let the lens hood reach to the anti-dazzling location and filter the lights traveling from the light source onto the image sensor; next, to let CPU execute an image analysis software program to process on the image information measured by the image sensor to compute the light sourceíªs color temperature value; drive the lens hood away from the anti-dazzling location; and based on the color temperature value invoke a CPU to control the digital camera to perform white balance correction. Therefore, the digital camera can act as a color temperature meter capable of measuring and computing the environmental color temperature value, and the digital camera can use the color temperature value to automatically perform the white balance correction with high accuracy.

Description

The present invention relates to digital cameras, and more particularly to methods and apparatus for automatically white balancing digital cameras. [Prior Art]

When a digital camera captures image information with a CCD or CMOS image sensor, the chromaticity values of r (red), G (green), and β (blue) of each image pixel (Pixel) obtained by the digital camera are subject to the environment. The influence of the color temperature of the light source is different, and the color is shifted; for example, when the color temperature of the light source is low, the image captured by $ exhibits a hue shifted to red and yellow, and when the color temperature of the light source is high, the cyan shift is high. The color tone causes distortion of the image color; therefore, the R, G, and Β values of each image pixel are white balanced to adjust the color shift caused by the light source. '- Taiwan Patent Notice No. 58387, published on April 11, 2004, discloses an automatic white balance correction method for an image manipulation device, which first uses a device to capture a color image, followed by RGB or The γϋν color space performs gray point search, and calculates the correction coefficient of the red, green and blue primary colors of each gray point pixel; then averages the correction coefficient groups of all the gray points to ^^ a corrected average group; The corrected average group performs color correction on each pixel of the color image in color space 2 to adjust the most accurate white balance. Taiwan Patent Publication No. 571 1 75, published on January 1, 2004, discloses a method and apparatus for automatically correcting white balance, which may be established in advance by giving environmental characteristics to the model. Several models of the environment will be added. The digital image data of Beacon is modulated and corresponding to the parameters of the light model.

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, the comparison 'final selection of the highest probability light (four) parameters as white balance parameters. Therefore, fixed and correct white balance gain value and B gain value can be given for each environment, and the data can be read at any time. The built-in database can be flexibly changed at any time to match the color of various optical machines. The difference is the difference between the power of the month b and the quality of the white balance. The above known method of using the arithmetic method to automatically white balance the digital camera still does not obtain the correct white balance correction. The way to move the balance is to let the user know the current environment, the fox and then set the white balance of the digital camera before shooting: II. However, when the user determines that the color temperature value is different, “the correct white balance correction. After all the automatic or manual white leveling is paid, the most accurate way is to make the white balance correction value set the most accurate. White balance correction with color temperature meter, you need to shoot before each shooting, it is not convenient to use [inventory content] Balance method 'has a color temperature meter with error, accurately measure the color temperature into the camera, and then shoot That is, when the user takes a photo, he or she needs to carry the measured color temperature with him, and then set the camera, so that the digital camera can automatically and automatically perform white balance correction to change the various missing details of the known white balance correction method. The present invention has been made. The main object of the present invention is to provide a digital camera automatic white method and apparatus for enabling an accurate white balance correction for a digital camera. Another object of the present invention is to provide a digital camera automatic white. Method and device' can avoid over-correction of white balance of general digital camera

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phenomenon. Another purpose of the square 5 is to provide a digital camera with an automatic white balance that allows the user to automatically white balance the digital camera by using a color thermometer. For other purposes and effects of the clothing, please refer to the drawings and examples, as detailed below. π [Embodiment] η ^ ί t, mainly to make the digital camera and the function of the color temperature meter, measure the color temperature value of the brother, and make the digital camera automatically enter according to the color temperature value.

White = balance correction, so that the digital camera can get accurate white balance correction. Referring to FIG. 1 , the first embodiment of the device of the present invention mainly causes the light emitted by the light source 10 to pass through a hood 21 to enter the CCD image sensor 22 or the CMOS image sensor of the digital camera. And the cpu inside the digital camera calculates the color temperature value of the light source 1 according to the image information measured by the image analysis software and the CCD image sensor 22. Then let cp[J adjust the white balance of the digital camera according to the color temperature value, or control the display of the color temperature value of the digital camera to make the digital camera have the function of the color temperature meter.

In this embodiment, the hood 21 is disposed between the lens group 23 inside the digital camera and the CCD image sensor 22, and a power member 24 drives the hood 21 to or from the position where the hood is closed, and the power member 24 is electrically connected to the digital position. The camera's CPU. When metering is to be performed, the CPU controls the power member 24 to bring the mask 21 to the light-shielding position, and filters the light entering the CCD image sensor 22 to prevent the CCD image sensor 22 from being overexposed. When the color temperature value is obtained, the CPU controls the power member 24 to drive the hood 2 1 away from the shading position, so that the digital phase

Page 7 1290662 V. INSTRUCTIONS (4) The machine can perform photography. The power member 24 can be a motor coupled to a link to drive the hood 21. Please refer to Figure 2. In the second embodiment of the device of the present invention, the hood 25 can be manually placed outside the lens group 23 of the digital camera without the need for a power component, and the light entering the CCD image sensor 22 can be filtered to avoid CCD image sensing. 2 2 overexposed, and the digital camera calculates the color temperature value. The hood of the digital camera automatic white balance device of the present invention is preferably

A white hood provides better shading and a better color temperature value. Please refer to Figure 3. The method for automatically white balancing the digital camera of the present invention is a method for automatically white balancing a digital camera by using a CPU of a digital camera, a CCD image sensor, an image analysis software, a hood, and a power component, including the following steps: (1) The CPU controls the power component to drive the hood to the shading position, and filters the light entering the CCD image sensor by the light source; (2) causing the CPU to calculate the light source according to the image analysis software and the image information measured by the CD image sensor. Color temperature value;

(3) The C P U controls the digital camera to perform white balance correction according to the 6 black temperature value, and controls the power component to drive the hood away from the shading position; (4) causes the CPU to control the display of the digital camera to display the color temperature value. The shading position of the hood of the above step (1) is between the lens group of the digital camera and the CCD image sensor. The method of the invention can also drive the hood without the CPU to control the power component, and manually shield the hood.

Page 8 1290662 V. INSTRUCTIONS (5) Cover The hood is placed outside the lens group of the digital camera to filter the light entering the lens group from the light source. The method of the present invention also does not require the above step (4) to cause the digital camera to display a color temperature value design. The present invention enables the digital camera to have the function of a color temperature meter, and can measure and calculate the ambient color temperature value' and automatically adjust the white balance of the digital camera according to the color temperature value, so that the digital camera can obtain accurate white balance correction. The above description is only for the embodiments of the present invention, and any modifications and variations made by those skilled in the art using the present invention are the scope of patents of the present invention, and are not limited to those disclosed in the embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing a first embodiment of a device embodying the present invention. Figure 2 is a schematic illustration of a second embodiment of a device embodying the invention. Figure 3 is a flow chart for carrying out the invention. [Main component symbol description] 10 Light source 21, 25 hood 2 2 CCD image sensor 23 Lens group 24 Power components 1 Step (1)

2 Step (2) 3 Step (3) 4 Step (4)

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Claims (1)

1290662 Sixth, the scope of application for patents 1 - a digital camera automatic CPU, image sensor, and balance method, the use of digital camera automatic white balance of the square, to the image analysis software and a hood to make the digital phase (1 The hood is brought to the opaque position to include the following steps: ray; m is set to filter from the light source into the image sensor (2) to make the CPU according to the image, 篡兮# & fortunate human body and image sensor The color temperature value of the measured image is different from that of the source; (3) driving the hood to remove the noise, and removing the light from the shading position; and causing the CPU to control the digital camera to perform white balance correction according to the color temperature value. 2 · The method of claiming a patent||The method of automatic white balance of the digital camera described in Item 1 wherein the hood of the hood is located between the lens group of the digital camera and the image sensor. 3. The square of the automatic white balance of the digital camera described in claim 1 wherein the hood is placed outside the lens group of the digital camera. 4. The method of claiming the automatic white balance of the digital camera according to claim 1, wherein in the steps (1) and (3), the CPU controls a power component to drive the hood to or from the light shielding position. . 5. The method of claiming the automatic white balance of the digital camera according to the first aspect of the patent, wherein the hood is a white hood. 6. The digital camera according to claim 3, wherein the step (1) and (3) manually drive the cover to or from the light-shielding position. Any of the digital cameras described above automatically. 7. If the patent application range is from 1 to 2, the following steps include a white balance method, in which the less than () Page 11 __ 1290662 VI. Scope of Application Patent Procedure: Cause the CPU to control the display of the digital camera to display the color temperature value. 8. The method of automatic white balance of a digital camera as described in claim 7 wherein the image sensor is a CCD image sensor. 9. The method of automatic white balance of a digital camera as described in claim 7 wherein the image sensor is a CMOS image sensor. 1 0 · a digital camera automatic white balance device, comprising a digital camera combined with a power member, the power member is combined with a hood; the power member is electrically connected to the CPlJ of the digital camera; when the meter is to be metered, the CPU That is, controlling the power component to drive the hood to the light-shielding position, filtering the light entering the image sensor of the digital camera by the light source, preventing the image sensor from being overexposed, and then causing the CPU to sense the image according to the image analysis software and the image. The image information measured by the device 'calculates the color temperature value of the light source, and then controls the digital camera to perform white balance correction according to the color temperature value, and controls the power member to drive the 3 hood to leave the light shielding position. 1 1 ·如The device of claim 3, wherein the hood of the digital camera is disposed between the lens of the digital camera and the image sensor. 1 2 The apparatus for automatic white balance of a digital camera according to claim 11, wherein the hood is a white hood. 1 3 The method of automatic white balance of a digital camera according to claim 12, wherein the image sensor is a CCD image sensor. 14. A method of automatic white balance of a digital camera as claimed in claim 12 wherein the image sensor is a CMOS image sensor. Page 12