TWI726593B - Color temperature box and control method thereof - Google Patents

Abstract

The invention provides a color temperature box and a control method thereof. The method includes: obtaining a sampling frequency of a photographing instrument; obtaining a light flickering frequency of the color temperature box; and in response to determining that the sampling frequency of the photographing instrument is higher than the light flickering frequency of the color temperature box, adjusting the light flickering frequency of the color temperature box to be not lower than the sampling frequency of the photographing instrument.

Description

Color temperature box and its control method

The invention relates to a color temperature box and a control method thereof.

In the prior art, the color temperature box is often used with a camera or mobile phone and other shooting instruments that can obtain the current color temperature image of the color temperature box. However, if the flickering frequency of the bulb of the color temperature box is different from the sampling frequency of the shooting instrument, the black border 100 shown in FIG. 1 may be generated in the image or movie shot by the shooting instrument. As a result, it is impossible to successfully capture the actual image conditions in the color temperature box.

In view of this, the present invention provides a color temperature box and a control method thereof, which can be used to solve the above technical problems.

The invention provides a color temperature box control method, which is suitable for connecting to a color temperature box of a photographing instrument. The method includes: obtaining a sampling frequency of the photographing instrument; obtaining a light bulb flashing frequency of the color temperature box; responding to determining that the sampling frequency of the photographing instrument is higher than the light bulb flashing frequency of the color temperature box, adjusting the light bulb flashing frequency of the color temperature box to not lower The sampling frequency of the shooting instrument.

The invention provides a color temperature box, which includes a spectrum lamp and a controller. The controller is coupled to the spectrum lamp, and is configured to: obtain a sampling frequency of a photographing instrument connected to the color temperature box; obtain a bulb flicker frequency of the spectrum lamp; respond to determining that the sampling frequency of the photographing instrument is higher than the bulb flicker of the spectrum lamp Frequency, adjust the flashing frequency of the light bulb of the spectrum lamp to be no lower than the sampling frequency of the shooting instrument.

Based on the above, the color temperature box and its control method of the present invention can adjust the light bulb flashing frequency of the color temperature box to not be lower than the sampling frequency of the color temperature box when it is determined that the sampling frequency of the photographing instrument is higher than the light bulb flickering frequency of the color temperature box. In this way, it is possible to avoid the occurrence of black borders in the images shot by the shooting instrument.

Please refer to FIG. 2, which is a schematic diagram of a color temperature box and a photographing instrument according to an embodiment of the present invention. As shown in FIG. 2, the color temperature box 200 of the present invention may include a spectrum lamp 202, a controller 204 and a color temperature sensing element 206. In different embodiments, the spectrum setting 202 is, for example, a general spectrum lamp that can present a specific color temperature, or an adjustable spectrum lamp that can present a specified color temperature according to user requirements, but it is not limited to this. In addition, the color temperature sensor 206 can be used to detect the current color temperature presented by the spectral lamp 202. In some embodiments, the controller 204 can determine whether the spectrum lamp 202 has a color temperature attenuation based on the current color temperature detected by the color temperature sensor 206, and perform color temperature compensation accordingly, and the details will be described later. .

As shown in FIG. 2, the controller 204 can be coupled to the spectrum lamp 202 and the color temperature sensing element 206. In some embodiments, if the spectral lamp 202 is an adjustable spectral lamp, the controller 204 can be used to adjust the color temperature presented by the spectral lamp 202. In addition, the controller 204 can also adjust the flashing frequency of the bulb of the spectrum lamp 202 by controlling a pulse width modulator (PWM) corresponding to the spectrum lamp 202.

In the embodiment of the present invention, the controller 204 can implement the color temperature box control method proposed by the present invention by accessing specific modules and program codes. The details of the control method are as follows.

Please refer to FIG. 3, which is a flowchart of a color temperature box control method according to an embodiment of the present invention. The method of this embodiment can be executed by the color temperature box 200 of FIG. 2. The details of each step in FIG. 3 are described below with the components shown in FIG. 2.

In the embodiment of the present invention, in order to improve the technical problems mentioned in the prior art, the following temporarily assumes that the color temperature box 200 is connected to a photographing instrument 210 (such as various cameras) through a transmission interface (such as a USB) as shown in FIG. 2.

Therefore, in step S310, the controller 204 can obtain the sampling frequency of the photographing instrument 210, which is, for example, the frame per second (FPS) when the photographing instrument 210 is photographed. In the embodiment of the present invention, the controller 204 can obtain the sampling frequency of the photographing instrument 210 based on any existing means.

After that, in step S320, the controller 204 can obtain the bulb flicker frequency of the color temperature box 200, that is, the bulb flicker frequency of the spectral lamp 202. In some embodiments, the controller 204 can, for example, directly read the relevant system parameters of the color temperature box 200 to obtain the bulb flicker frequency of the spectrum lamp 202, but it is not limited to this.

Generally speaking, the flickering frequency of the bulb of the spectrum lamp 202 will be the same as the flickering frequency of a general indoor lamp tube at 60 Hz. However, as stated in the prior art, if the flickering frequency of the bulb of the spectral lamp 202 is not higher than the sampling frequency of the shooting instrument 210 (may be 60Hz, 90Hz, 120Hz, 240Hz), the image captured by the shooting instrument 210 may appear as shown in the figure. 1 shows the black border 100.

Therefore, in step S330, in response to determining that the sampling frequency of the photographing instrument 210 is higher than the light bulb flickering frequency of the color temperature box 200, the light bulb flickering frequency of the color temperature box 200 is adjusted to not be lower than the sampling frequency of the photographing instrument 210. In some embodiments, the controller 204 can adjust the bulb flicker frequency of the spectrum lamp 202 by controlling the PWM corresponding to the spectrum lamp 202 as previously described, but it is not limited to this.

In different embodiments, the controller 204 may predetermine a number of available light bulb flashing frequencies (for example, 300 Hz, 144 Hz, 120 Hz, 90 Hz, 60 Hz, 50 Hz, etc.), and may obtain the sampling frequency of the photographing instrument 210 from these One of the available bulb flicker frequencies is selected as the bulb flicker frequency of the spectrum lamp 202 that is not lower than the above-mentioned sampling frequency.

Please refer to Table 1 below, which illustrates the lamp flashing frequencies that the controller 202 can set for various sampling frequencies. Sampling frequency Lamp flashing frequency 60Hz 90Hz 90Hz 120Hz 120Hz 144Hz 240Hz 300Hz Table 1

It can be seen from Table 1 that if the sampling frequency of the photographing instrument 210 is 60 Hz, the controller 204 can adjust the flashing frequency of the bulb of the spectrum lamp 202 to 90 Hz; if the sampling frequency of the photographing instrument 210 is 90 Hz, the controller 204 can adjust The bulb flicker frequency of the spectral lamp 202 is adjusted to 120 Hz; if the sampling frequency of the photographing instrument 210 is 120 Hz, the controller 204 can adjust the bulb flickering frequency of the spectral lamp 202 to 144 Hz; if the sampling frequency of the photographing instrument 210 is 240 Hz, control The device 204 can adjust the flashing frequency of the bulb of the spectrum lamp 202 to 300 Hz. In this way, black edges can be avoided in the image captured by the camera 210.

It should be understood that Table 1 is only used as an example, and is not used to limit the possible implementations of the present invention. For example, if the sampling frequency of the photographing instrument 210 is 60 Hz, the controller 204 may also choose to adjust the bulb flicker frequency of the spectrum lamp 202 to other values not less than 60 Hz, such as 120 Hz/144 Hz/300 Hz and so on.

In addition, in some embodiments, the controller 202 of the present invention can determine whether the light bulb flashing frequency of the spectral lamp 202 of the color temperature box 200 needs to be adjusted to a preset value after detecting that the color temperature box 200 is disconnected from the photographing instrument 210. Set the flicker frequency (for example, 50Hz or 60Hz). In one embodiment, the controller 202 can determine whether the flickering frequency of the bulb of the spectral lamp 202 is equal to the aforementioned preset flicker frequency, and if not, it can determine that the flickering frequency of the bulb of the spectral lamp 202 needs to be adjusted to the aforementioned preset flicker frequency.

In response to determining that the bulb flicker frequency of the spectral lamp 202 of the color temperature box 200 needs to be adjusted to the preset flicker frequency, the controller 204 can adjust the bulb flicker frequency of the color temperature box 200 to the preset flicker frequency.

Specifically, in some embodiments, if the bulb flicker frequency of the spectrum lamp 202 is maintained at a higher frequency for a long time, the service life of the spectrum lamp 202 may also be shortened. In addition, in some specific fields (such as certain factory production lines), because the local indoor lamps may have a relatively special preset flicker frequency (such as 50Hz), the above technical means can make the spectrum lamp 202 The light bulb flicker frequency is adjusted to the preset flicker frequency after the color temperature box 200 is disconnected from the photographing instrument 210, so that the spectrum lamp 202 can be used to simulate the environment of the above-mentioned specific field, and at the same time, the use of the spectrum lamp 202 is extended life.

In addition, the spectrum lamp in the color temperature box sold on the market will have the problem of color attenuation of the bulb after about half a year to one year, and the user must return the color temperature box to the original factory to adjust the color temperature of the bulb. However, due to factors such as the expensive cost, the volume and weight of the light box, and the complicated color calibration process, the above method is extremely inconvenient for the user.

Therefore, the present invention also proposes a related color temperature compensation mechanism to improve the above technical problems. Specifically, in one embodiment, the controller 202 can detect the current color temperature of the spectral lamp 202 (for example, an adjustable spectral lamp) through the color temperature sensing element 206.

After that, the controller 204 can determine whether the current color temperature matches a target color temperature. In different embodiments, the target color temperature is, for example, the color temperature that the spectral lamp 202 should present. However, since the spectrum lamp 202 may have the problem of bulb color attenuation as described above, the current color temperature of the spectrum lamp 202 may not match the above-mentioned target color temperature.

、

、

等色座標表示）與當下色溫（以對應的

、

、

等色座標表示）之間的轉換關係可表示如下式(1)：

(1) ，其中T為轉換式，

、

、

、a、b、g、d、h、e、b為用於將當下色溫轉換為目標色溫的轉換參數，其中由於目標色溫及當下色溫皆為已知，故控制器204可基於基本的矩陣運算原則找出上述各轉換參數，並用以將當下色溫轉換為目標色溫。此外，上式(1)中亦可包括分別對應於

、

、

的

、

、

等（可選的）修正參數，其可在控制器204以T對

、

、

進行運算之後，用於將運算結果修正為

、

、

，但可不限於此。 Therefore, in response to determining that the current color temperature does not match the target color temperature, the controller 202 can adjust the current color temperature of the spectral lamp 202 to the target color temperature through a conversion method, and vice versa, the current color temperature may not be adjusted. In one embodiment, the target color temperature (with the corresponding

,

,

Is expressed in isochromatic coordinates) and the current color temperature (in the corresponding

,

,

The conversion relationship between isochromatic coordinates can be expressed as the following formula (1):

(1), where T is the conversion formula,

,

,

, A, b, g, d, h, e, b are conversion parameters for converting the current color temperature to the target color temperature. Since the target color temperature and the current color temperature are both known, the controller 204 can be based on basic matrix calculations. In principle, find the above conversion parameters and use them to convert the current color temperature to the target color temperature. In addition, the above formula (1) can also include corresponding to

,

,

of

,

,

And other (optional) correction parameters, which can be adjusted with T in the controller 204

,

,

After the calculation is performed, it is used to correct the calculation result to

,

,

, But not limited to this.

In other embodiments, if the color temperature box 200 is additionally connected to a related computing device (such as a computer device), the calculation of the conversion formula can also be calculated by the computing device based on the target color temperature and the current color temperature provided by the controller 204, and provide accordingly It is assigned to the controller 204, but the present invention may not be limited to this.

In summary, the color temperature box and its control method of the present invention can adjust the light bulb flashing frequency of the color temperature box to be no lower than the sampling frequency of the color temperature box when it is determined that the sampling frequency of the photographing instrument is higher than the light bulb flashing frequency of the color temperature box. In this way, it is possible to avoid the occurrence of black borders in the images shot by the shooting instrument. In addition, the present invention also proposes a color temperature compensation mechanism, which can be used to correct the current color temperature of the spectrum lamp to match the specified target color temperature when it is detected that the current color temperature of the spectrum lamp of the color temperature box does not match the specified target color temperature. In order to prevent the spectrum lamp from being unable to correctly present the specified color temperature due to the color temperature attenuation.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the relevant technical field can make some changes and modifications without departing from the spirit and scope of the present invention. The scope of protection of the present invention shall be determined by the scope of the attached patent application.

100: black border

200: color temperature box

202: Spectral light

204: Controller

206: color temperature sensor

210: shooting instrument

S310~S330: steps

Figure 1 is a schematic diagram of the conventional black border of an image. Fig. 2 is a schematic diagram of a color temperature box and a photographing instrument according to an embodiment of the present invention. FIG. 3 is a flowchart of a color temperature box control method according to an embodiment of the present invention.

S310~S330: steps

Claims (9)

A color temperature box control method, suitable for being connected to a color temperature box of a photographing instrument, the color temperature box including an adjustable spectrum lamp and a color temperature sensing element, the method includes: obtaining a sampling frequency of the photographing instrument; The flashing frequency of a bulb of the color temperature box; the current color temperature of the adjustable spectrum lamp is detected through the color temperature sensing element; in response to determining that the sampling frequency of the shooting instrument is higher than the flashing frequency of the bulb of the color temperature box, the color temperature box Adjust the flickering frequency of the bulb to not be lower than the sampling frequency of the shooting instrument; and in response to determining that the current color temperature does not match a target color temperature, adjust the current color temperature of the adjustable spectrum lamp to the target through a conversion method Color temperature, otherwise, the current color temperature is not adjusted. The method according to claim 1, further comprising: in response to detecting that the color temperature box is disconnected from the photographing instrument, determining whether the light bulb flashing frequency of the color temperature box needs to be adjusted to a preset flashing frequency; It is determined that the light bulb flickering frequency of the color temperature box needs to be adjusted to the preset flicker frequency, and the light bulb flickering frequency of the color temperature box is adjusted to the preset flicker frequency. The method according to claim 2, wherein the step of determining whether it is necessary to adjust the flashing frequency of the bulb of the color temperature box to the preset flashing frequency includes: responding to determining that the flashing frequency of the bulb of the color temperature box is not equal to the preset flashing Frequency, it is determined that the flashing frequency of the bulb of the color temperature box needs to be adjusted to the preset flashing frequency. The method according to claim 2, wherein the preset frequency is 50 Hz. A color temperature box includes: a spectrum lamp; and a controller coupled to the spectrum lamps and configured to: obtain a sampling frequency of a photographing instrument connected to the color temperature box; obtain a bulb of the spectrum lamp Flicker frequency; in response to determining that the sampling frequency of the shooting instrument is higher than the flickering frequency of the bulb of the spectrum lamp, the bulb flickering frequency of the spectrum lamp is adjusted to not be lower than the sampling frequency of the shooting instrument. The color temperature box according to claim 5, wherein the controller is further configured to: in response to detecting that the color temperature box is disconnected from the photographing instrument, determine whether it is necessary to adjust the flashing frequency of the bulb of the color temperature box to A preset flicker frequency; in response to determining that the light bulb flicker frequency of the color temperature box needs to be adjusted to the preset flicker frequency, and the light bulb flicker frequency of the color temperature box is adjusted to the preset flicker frequency. The color temperature box according to claim 6, wherein the controller is configured to: respond to determining that the light bulb flashing frequency of the color temperature box is not equal to the preset flashing frequency, and the light bulb flashing frequency of the color temperature box is semi-determinable Adjust to the preset flashing frequency. The color temperature box according to claim 6, wherein the preset frequency is 50 Hz. The color temperature box according to claim 5, wherein the spectrum lamp is an adjustable spectrum lamp, the color temperature box further includes a color temperature sensing element coupled to the controller, and the controller is further configured to: Detect a current color temperature of the adjustable spectrum lamp through the color temperature sensing element; in response to determining that the current color temperature does not match a target color temperature, adjust the current color temperature of the adjustable spectrum lamp to the target color temperature through a conversion method , Otherwise, the current color temperature will not be adjusted.

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