KR101442607B1 - Apparatus and method for controlling color temperature of image using color temperature control filter - Google Patents

Abstract

The present invention relates to a digital image processing apparatus and method, and more particularly, to a digital image processing apparatus and method in which a color temperature filter is mounted on a front surface of a flash, and a proper color temperature filter is selected before shooting, Apparatus and method. The color temperature control device of the image using the color temperature control filter is a color temperature filter which is mounted on the front side of the flash and supports various colors to change the color temperature of the input image. And digital signal processing means for calculating a color temperature of the live view image adjusted in white balance and selecting a color temperature filter most similar to the calculated color temperature and taking an image together with the flash light.

Color Temperature Filter, Color Temperature Calculation, Flash

Description

[0001] The present invention relates to an apparatus and method for controlling color temperature of an image using a color temperature control filter,

The present invention relates to a digital image processing apparatus and method, and more particularly, to a digital image processing apparatus and method in which a color temperature filter is mounted on a front surface of a flash, and a proper color temperature filter is selected before shooting, Apparatus and method.

The flash of the digital image processing device controls the erection by adjusting the current flowing in the flash. Therefore, if the flash is blasted and the image is photographed, a non-luminescent image is obtained because the color is more intense than when the non-luminescent photographing is performed.

For example, the auto white balance (AWB) does not match the flash, resulting in a bluish overall picture, and the white balance of the person is the natural white color, but the background where the flash light can not reach is green or yellow Or red.

The color temperature of the flash has a color temperature higher than the color temperature of a normal natural light source. Therefore, it is blue rather than the normal light source, and the flash is usually used in a dark light source. Therefore, when the flash is photographed, there occurs a difference between the flash light amount and the color temperature of the light source at the time of shooting. Depending on the blending ratio of the two light sources (or the combined light sources), the color temperature of the subject differs do. The white balance is often distorted.

Even if the white balance is correct, the amount of time the flash reaches the subject and the background differs depending on the exposure, so the color temperature difference between the subject and the background occurs. If you perform white balance based on the subject, When the white balance is performed on the background, the subject is photographed with a strange color.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a method and an apparatus for predicting color temperature in a live view image in which an automatic white balance is adjusted and selecting a color temperature filter, And a method of controlling the color temperature of an image using the color temperature control filter.

According to an aspect of the present invention, there is provided an apparatus for controlling a color temperature of an image using a color temperature control filter, the apparatus comprising: a color temperature sensor for detecting a color temperature filter; And digital signal processing means for calculating a color temperature of the live view image adjusted in white balance and selecting a color temperature filter most similar to the calculated color temperature and photographing the image together with the flash light.

In the present invention, the digital signal processing unit may include: a color temperature calculation unit for calculating a color temperature of the live view image corrected for white balance; A color temperature filter selecting unit for selecting a color temperature filter most similar to the calculated color temperature; And a control unit for capturing an image together with the flash light when the bio color temperature filter selection is completed.

According to an aspect of the present invention, there is provided a method of controlling a color temperature of an image using a color temperature control filter, the method comprising the steps of: (a) inputting a digital image having a color temperature filter A method of operating a processing device, the method comprising: (a) calculating a color temperature of a live view image that is white balance adjusted; (b) selecting the color temperature filter most similar to the calculated color temperature; And (c) photographing the live view image together with the flash light.

According to the present invention, the color temperature is predicted in the live view image in which the automatic white balance is adjusted, and the color temperature filter mounted on the front face of the flash is selected in a manner similar to the predicted color temperature, It is possible to prevent the occurrence of errors and errors in the automatic white balance due to the reduction of the color temperature difference between the subject which is highly influenced by the flash and the background which is less influenced by the flash.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing the front and top contours of a digital image processing apparatus. Fig.

The shutter-release button 11 is opened and closed to expose the CCD or film to light for a predetermined time, and the image is recorded on the CCD by appropriately exposing the subject in cooperation with the aperture (not shown).

The shutter-release button 11 generates the first and second image pickup signals by the photographer input. When the first shutter-release button 11 is input as a half-shutter signal, the digital image processing apparatus focuses and adjusts the amount of light. At this time, the display unit 25 is lit with a green light . When the focus of the first shutter-release button 11 is focused and the amount of light is adjusted, a second shutter-release button 11 as a full shutter signal is input to capture an image.

The power button 13 is inputted to supply power to the digital image processing apparatus and operate it.

The flash 15 illuminates bright light momentarily when shooting in a dark place. The flash mode includes auto flash, forced flash, no flash, red-eye reduction, and slow synchro flash.

The auxiliary light 17 supplies light to the subject so that the digital image processing apparatus automatically catches the focus quickly and accurately when the light amount is insufficient or at night.

The lens unit 19 receives light from an external light source and processes the image.

FIG. 2 is a rear view showing the rear external appearance of the digital image processing apparatus shown in FIG. 1. The wide-angle zoom button 21w, the telephoto-zoom button 21t, the display unit 23, Input buttons B1 to B14 (hereinafter referred to as buttons B1 to B14).

The wide-angle zoom button 21w or the telephoto-zoom button 21t widens the view angle or narrows the view angle depending on the input, in particular, when the size of the selected exposure area is to be changed. When the wide angle-zoom button 21w is input, the size of the selected exposure area is reduced, and when the telephoto-zoom button 21t is input, the size of the selected exposure area is increased.

The buttons B1 to B14 are provided in the rows and columns of the display unit 23. The buttons B1 to B14 provided in the row and column of the display unit 23 are provided with a touch sensor (not shown) or a contact type switch (not shown).

That is, the touch sensors are provided on the buttons B1 to B14 to move up / down / left / right while touching the buttons B1 to B7 of the horizontal row or the buttons B8 to B14 of the vertical row, It is possible to select any value (e.g., color or brightness) of the items, or activate a submenu icon included in the main menu icon.

In addition, the button frames (B1 to B14) are provided with contact switches so that the main menu icon and the sub menu icon can be directly selected to execute the corresponding function. The touch sensor requires a relatively weak touch compared to the contact switch input, but the contact switch input requires a relatively strong touch compared to the touch sensor input.

FIG. 3 is a block diagram illustrating a configuration of an apparatus for controlling color temperature of an image using a color temperature control filter according to the present invention. The display unit 23, the user input unit 31, the image pickup unit 33, the image processing unit 35, A digital signal processing unit 39, and a color temperature filter 41. The digital signal processing unit 39,

The user input unit 31 includes a shutter release button 11 that is opened and closed to expose a CCD or a film to light for a predetermined period of time, a power button 13 that inputs power to supply power, Zoom button 21w and telephoto-zoom button 21t for narrowing down the screen and a touch sensor or contact type switch provided in the horizontal and vertical columns around the display unit 23 for character input or menu selection and execution, And buttons B1 to B14 provided with buttons.

The imaging section 33 includes a shutter, a lens section, a diaphragm, and a charge coupled device (CCD) and an ADC (not shown). The shutter is a mechanism that adjusts the amount of light that is exposed with the iris. The lens unit receives light from an external light source and processes the image. At this time, the diaphragm adjusts the amount (light amount) of the incident light according to the degree of opening and closing. The opening / closing degree of the diaphragm is controlled by the digital signal processing section 39. [

The CCD accumulates the amount of light input through the lens unit and outputs the image captured by the lens unit according to the accumulated light amount in accordance with the vertical synchronization signal. Image acquisition of a digital image processing apparatus is performed by a CCD which converts light reflected from a subject into an electrical signal. In order to obtain a color image using a CCD, a color filter is required, and a filter (not shown) called a color filter array (CFA) is employed in most cases. CFA has a regularly arranged structure that passes only light that represents one color per pixel, and it has various forms according to the arrangement structure. The ADC converts the analog video signal output from the CCD into a digital signal.

The image processing unit 35 processes the digitally converted RAW data so that it can be displayed. The image processing unit 35 removes a black level due to the dark current generated in the CCD and the CFA filter which are full of temperature change. The image processing unit 35 performs gamma correction to encode information in accordance with the nonlinearity of human vision. The image processing unit 35 performs CFA interpolation for interpolating the Bayer pattern implemented with the GGR-corrected RGRG line and the GBGB line into RGB lines. The image processing unit 35 converts the interpolated RGB signals into YUV signals, performs edge compensation for filtering the Y signals by a high-pass filter, and calculates color values of the U and V signals using a standard color coordinate system Corrects the color correction, and removes these noises. The image processing unit 35 compresses and processes the Y, U, and V signals from which the noise has been removed to generate a JPEG file, and the generated JPEG file is displayed on the display unit 23 and stored in the storage unit 37 . All the operations of the image processing unit 35 operate under the control of the digital signal processing unit 39. [

The digital signal processing unit 39 calculates the color temperature of the live view image in which the white balance is adjusted, selects the color temperature filter 41 most similar to the calculated color temperature, and shoots the image together with the flash 15 light emission.

The color temperature filter 41 is mounted on the front surface of the flash 15 and supports various colors to change the color temperature of the input image. The color temperature filter 41 is a film type filter for adjusting the color temperature of the illumination light when the chromaticity of the illumination light is different from that of the color light in the color image photographing. The color temperature filter 41 has a blue color system for increasing the color temperature, have.

As shown in FIG. 4A, the color temperature filter 41 is mounted on the front side of the barrel, and a plurality of color correction filters are attached to the rotation disk. By the rotation of the color temperature filter 41, the respective color correction filters are switched and inserted on the optical path Lt; / RTI > Or the color temperature filter 41 may be mounted on the front surface of the flash 15 as shown in FIG. 4B so that the respective color correction filters can be switched by the up, down, left, and right movements so as to be inserted on the optical path. The color temperature filter 41 can be manually or automatically selected. In the case of automatic selection, a motor (not shown) is provided to select a color correction filter according to the movement of the motor under the control of the digital signal processing unit 39.

Examples of the color correction filter mounted on the color temperature filter 41 include a color filter for 3200K suitable for light generated in an incandescent lamp, a color filter for 4500K suitable for light generated in a fluorescent lamp, 5600K + 1 / 8ND suitable for outdoor daylight, And 5600K suitable for outdoor light.

The digital signal processing unit 39 includes a color temperature calculation unit 39-1, a color temperature filter selection unit 39-2, and a control unit 39-3 for color temperature control.

The color temperature calculation unit 39-1 calculates the color temperature of the live view image subjected to the white balance correction. The white balance correction of the live view image is performed by comparing the color coordinates of the R, G, and B color coordinates of the pixels displayed in white with the white coordinates R, G, and B of the reference white, from the color information of the live view image, And applied to the entire live view image. The color temperature calculator 39-1 calculates the color temperature of the live view image that has been subjected to the white balance correction as described above. Since the content of the color temperature calculation is well known in the art such as the Robertson algorithm, a detailed description thereof will be omitted.

The color temperature filter selection unit 39-2 selects a color correction filter similar to the color temperature of the live view image corrected by the white balance calculated by the color temperature calculation unit 39-1. The controller 39-3 may output a color correction filter selection message for manual selection of the corresponding color correction filter. In order to automatically select the corresponding color correction filter, the controller 39-3 moves the motor You can select the color correction filter that is most similar to the color temperature of the view image.

The control unit 39-3 picks up an image together with the light emission of the flash 15 when the color correction filter selection in the color temperature filter 41 is completed and the shutter release button 11 is input. Therefore, it is possible to prevent the auto white balance from being changed and error due to the flash light emission, and to reduce the color temperature difference between the subject, which is relatively influenced by the flash 15 and the background less affected by the flash 15, Can be obtained.

Hereinafter, a color temperature control method of an image using the color temperature control filter according to the present invention will be described in detail with reference to FIG. The color temperature control method of the image using the color temperature control filter according to the present invention can be performed in the digital image processing apparatus as shown in FIG. 3. According to the embodiment, And can be performed in the digital signal processing unit 39 with assistance.

The digital signal processing unit 39 displays the live view image on the display unit 23 (step 501).

Then, when the flash color temperature adjustment menu is selected, the digital signal processing unit 39 switches the digital image processing apparatus to the flash color temperature adjustment mode (step 503).

When the first shutter-release button 11 is input (step 505), the digital signal processing unit 39 calculates the color temperature of the live-view image that has undergone white balance correction (step 507). The white balance correction on the live view image compares the color coordinates of the R, G, B color coordinates of the pixels displayed in white with the white coordinates R, G, B of the white displayed from the color information of the live view image, And applied to the entire live view image. The digital signal processing unit 39 calculates the color temperature of the live view image which has been subjected to the white balance correction as described above. The content of color temperature calculation is omitted because it has many contents already known, such as the Robertson algorithm.

When the calculation of the color temperature of the live view image is completed, the digital signal processor 39 recommends the color correction filter of the color temperature filter 41 which is most similar to the calculated color temperature (step 509).

The color temperature filter 41 is a film type filter for adjusting the color temperature of the illumination light when the chromaticity of the illumination light is different from the color balance in the image capturing. The color temperature filter 41 has a blue color system for increasing the color temperature and a non- , As shown in FIG. 4A, a plurality of color correction filters are mounted on the rotating disk mounted on the front side of the barrel, so that the respective color correction filters can be switched and inserted into the optical path by the rotation thereof 4b, the color correction filters can be switched by the up, down, left, and right movements so as to be inserted on the optical path.

When the color correction filter of the color temperature filter 41 is recommended, the digital signal processing unit 39 selects the corresponding color correction filter (step 511). The color temperature filter 41 can be manually or automatically selected. In the case of automatic selection, a motor (not shown) is provided to select a color correction filter according to the movement of the motor under the control of the digital signal processing unit 39.

When the selection of the color correction filter is completed, the digital signal processing unit 39 receives the input from the second shutter-release button 11 and captures an image at the same time that the flash 15 is emitted (step 513)

The digital signal processing unit 39 displays and stores the photographed image (step 515). Therefore, it is possible to prevent the auto white balance from being changed and error due to the flash light emission, and to reduce the color temperature difference between the subject, which is relatively influenced by the flash 15 and the background less affected by the flash 15, Can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing the front and top contours of a digital image processing apparatus. Fig.

FIG. 2 is a rear view showing the rear external appearance of the digital image processing apparatus shown in FIG. 1. FIG.

3 is a block diagram showing a configuration of an apparatus for controlling color temperature of an image using a color temperature control filter according to the present invention.

4 is a diagram showing an example of a digital image processing apparatus equipped with a color temperature adjustment filter.

5 is a flowchart illustrating an operation of a color temperature control method of an image using a color temperature control filter according to the present invention.

Claims (3)

A digital image processing apparatus comprising: A color temperature filter mounted on the front side of the flash for changing the color temperature of an input image by supporting various colors; And And a digital signal processing means for calculating a color temperature of the live view image adjusted in white balance and automatically selecting the color temperature filter based on the calculated color temperature and taking an image together with the flash light, Color temperature control device. The digital signal processing apparatus according to claim 1, wherein the digital signal processing means A color temperature calculation unit for calculating a color temperature of the live view image in which the white balance is corrected; A color temperature filter selecting unit for selecting a color temperature filter based on the calculated color temperature; And And a control unit for capturing an image together with the flash light when the color temperature filter is selected. A method of operating a digital image processing apparatus equipped with a color temperature filter mounted on a front surface of a flash and supporting various colors to change a color temperature of an input image, (a) calculating a color temperature of a live view image adjusted in white balance; (b) automatically selecting the color temperature filter based on the calculated color temperature; And (c) photographing the live view image together with the flash light.

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