TWI558194B - Calculating method of luminance of image - Google Patents

Description

Method for calculating screen brightness

This case involves a method. Specifically, the present invention relates to a method for calculating the brightness of a picture.

With the development of electronic technology, digital imaging has been widely used in people's lives.

A typical digital image device can form a preliminary image by using a photoelectric conversion program and signal processing, and processes the preliminary image by using an automatic exposure, auto focus, auto white balance, and the like to generate a digital image seen by the user. Among them, the automatic exposure program can determine the brightness of digital images, so it is an important research topic in the field for a long time.

An embodiment of the present invention relates to a method for calculating the brightness of a picture. According to an embodiment of the present invention, the method includes: obtaining an image data of a picture; generating at least one adjustment matrix according to the image data of the picture; And generating an adjusted photometry matrix according to the optical measurement matrix and the adjustment matrix; and metering the picture according to the adjusted photometry matrix to calculate a current picture brightness value of the picture.

By applying the above embodiment, the screen can be metered by the adjusted photometry matrix. In this way, the calculated current picture brightness value can be made more in line with the application requirements.

100‧‧‧Digital imaging device

110‧‧‧Image data acquisition unit

120‧‧‧ Controller

200‧‧‧ method

S1-S5‧‧‧ steps

LMX‧‧‧ Brightness Matrix

RGL‧‧‧ area brightness value

ADM1-ADM3‧‧‧ adjustment matrix

WGT1-WGT3‧‧‧ adjustment weight

MMX‧‧‧ metering matrix

MGT‧‧‧ weights

FGR‧‧‧ portrait

HFR‧‧‧High frequency area

W1-W2‧‧‧ adjustment weights

1 is a schematic diagram of a digital image device according to an embodiment of the present invention; FIG. 2 is a flow chart of a calculation method according to an embodiment of the present invention; and 3A-3C and 4-5 are based on Schematic diagrams of different operational examples of the present invention.

FIG. 1 is a schematic diagram of a digital image device 100 according to an embodiment of the present disclosure. In an embodiment, the digital image device 100 includes an image data capturing unit 110 and a controller 120. The image data capturing unit 110 and the controller 120 are electrically connected to each other.

In an embodiment, the image data capturing unit 110 can be implemented by, for example, a lens, a photosensitive element, and an associated circuit, but is not limited thereto. The controller 120 can be implemented by, for example, a central processing unit, a microprocessor, or an Intel 8051 single-chip microcontroller, but is not limited thereto.

In an embodiment, the image data capturing unit 110 is configured to perform image capturing on the environment image according to an initial parameter (for example, an initial exposure time and/or an initial gain of the photosensitive element) to obtain a The picture and the image data of this picture. Then, the image data capturing unit 110 is configured to transmit the image data to the controller 120.

In an embodiment, the controller 120 is configured to receive the image data, and perform a photometry on the image captured by the image data capturing unit 110 according to the image data to calculate a current screen brightness value of the image.

In the following, the brightness calculation method in FIG. 2 will be used to provide more specific details of the present invention, but the present invention is not limited to the following embodiments.

It should be noted that this brightness calculation method can be applied to a digital image device that is the same or similar to the structure shown in FIG. In order to simplify the description, the operation method will be described below by taking the digital image device 100 in FIG. 1 as an example in accordance with an embodiment of the present invention. However, the present invention is not limited to this application.

In addition, it should be understood that the steps of the brightness calculation method mentioned in the present embodiment can be adjusted according to actual needs, and can be performed simultaneously or partially simultaneously, unless the sequence is specifically described.

Furthermore, in various embodiments, such steps may also be adaptively added, replaced, and/or omitted.

Referring to FIG. 2, the brightness calculation method 200 includes the following steps.

In step S1, the controller 120 obtains a picture and video data of the picture through the image data capturing unit 110.

In an embodiment, the image data of the screen may include an initial brightness of the picture (eg, including a brightness matrix), a color of the picture. At least one of information (eg, including a color information matrix) and a detail of the screen (eg, including a detail information matrix).

In step S2, the controller 120 generates at least one adjustment matrix based on the image data.

In step S3, the controller 120 generates an adjusted photometry matrix according to a photometry matrix and the at least one adjustment matrix. In this embodiment, the photometry matrix is different from the adjustment matrix.

In an embodiment, the photometry matrix can be a central weighted photometric matrix, an average weighted photometric matrix, a spot photometric matrix, a ROI photometric matrix, a face metering matrix, or other suitable photometric matrix.

In an embodiment, the controller 120 may multiply all the elements in the one photometry matrix with the corresponding elements in the at least one adjustment matrix to generate an adjusted photometry matrix.

In step S4, the controller 120 meters the screen according to the adjusted photometric matrix to calculate a current screen luminance value of the screen.

In step S5, the controller 120 adjusts the parameters of the image data capturing unit 110 (for example, the exposure time and/or the gain of the photosensitive element according to the current picture brightness value of the picture and a target brightness value. Gain)), so that the image data capturing unit 110 performs image capturing on the environment image according to the new parameter to obtain a new image and image data. Then, step S1 is performed again.

In an embodiment, in a case where the current screen brightness value is close to the target brightness value, the controller 120 may stop adjusting the image data capturing unit 110. Parameters.

Through the above steps, the controller 120 can calculate the current picture brightness value of the picture corresponding to the image data. Thereby, the controller 120 can adjust the parameters of the image data capturing unit 110 more appropriately, so that the brightness of the captured image is more in line with the application requirements.

In order to clarify the description, several operation examples will be described below, but the present invention is not limited to the following operation examples.

Referring to Figures 3A-3C, in an operation example, the image data of the aforementioned picture includes an initial brightness of the picture. The initial brightness includes a brightness matrix LMX. The luminance matrix LMX includes a plurality of regional luminance values RGL. The area luminance values RGL correspond to a plurality of areas of the picture, respectively. The adjustment matrix ADM1 includes a plurality of adjustment weights WGT1. The adjustment weight WGT1 corresponds to the area luminance value RGL, respectively. In an embodiment, the controller 120 may determine the adjustment weight WGT1 in the adjustment matrix ADM1 according to the brightness relationship between the area luminance values RGL.

Specifically, in an embodiment, the controller 120 may determine the value of the adjustment weight corresponding to the extreme luminance value (such as the region luminance value RGL of the values 12, 65, 211, 212, 234, 255 in FIG. 3A). It is lower than the value of the adjustment weight corresponding to the intermediate luminance value (such as the region luminance value RGL whose value is not 12, 65, 211, 212, 234, 255 in FIG. 3A). For example, the values of the adjustment weights corresponding to the region luminance values RGL of the values of 12, 65, 211, 212, 234, and 255 are 3, 5, 5, 5, 3, 1, respectively, which are lower than the luminance values corresponding to other regions. The value of the adjustment weight (10).

In an embodiment, the adjustment weight corresponding to the intermediate brightness value The values are the same as each other.

In an embodiment, the extreme brightness value may include a plurality of (eg, five) values of the region luminance value RGL having the largest value and a plurality of (eg, five) values of the region luminance value RGL (as shown in FIG. 3A, the value is 12, The area luminance value RGL of 65, 99, 121, 122, 204, 211, 212, 234, 255.

In another embodiment, the extreme brightness value may include a region luminance value RGL whose value is lower than a preset lower threshold (eg, 70) and a value higher than a preset upper threshold (eg, 205) (as shown in FIG. 3A, the value is 12, 65, 211, 212, 234, 255 area brightness value RGL).

In an embodiment, the higher the brightness of the extreme high brightness value (such as the area brightness value RGL of the values 211, 212, 234, 255 in FIG. 3A), the lower the adjustment weight corresponding to the extremely low brightness value ( The lower the brightness of the area luminance value RGL) whose value is 12, 65 in Fig. 3A, the lower the adjustment weight corresponding thereto.

In an embodiment, the photometric matrix MMX is a central weighted photometric matrix comprising a plurality of weights MGT. The higher the weight of the center, the higher the MGT value.

In an embodiment, the controller 120 may multiply the weight MGT in the photometric matrix MMX by the corresponding adjustment weight WGT1 in the adjustment matrix ADM1 to generate an adjusted photometry matrix. For example, the weighted value of the top left of the adjusted metering matrix is 1*3=3, the weight of the top right is 1*10=10, and the weight of the bottom left is 1*5=5, the bottom right The weight value is 1*3=3, and the most central weight value is 10*10=100.

According to the adjusted photometry matrix, the controller 120 can calculate the current picture brightness of the picture while reducing the weight of the extreme brightness area. value. In this way, it is possible to prevent the current picture brightness value of the picture from being affected by extreme brightness areas, such as light sources in the picture.

Referring to Fig. 4, in an operation example, the aforementioned picture may include a portrait FGR. The image data of this screen may include a color information of the screen. This color information includes a color information matrix. The color information matrix includes a plurality of regional color information. The regional color information corresponds to a plurality of regions of the screen. The adjustment matrix ADM2 includes a plurality of adjustment weights WGT2. The adjustment weight WGT2 corresponds to the regional color information.

Since the color components of various human races have specific relationships in specific colors (for example, including red, green, and blue), in the foregoing picture, the plurality of colors in the regional color information corresponding to the portrait FGR have a specific relationship. . Therefore, in an embodiment, the controller 120 may determine the adjustment weight WGT2 in the adjustment matrix ADM2 according to the relationship between the plurality of colors in the regional color information.

Specifically, in an embodiment, the controller 120 may determine the adjustment weight WGT2 in the adjustment matrix ADM2 according to whether the color information of each area conforms to a preset color relationship. The value of the adjustment weight WGT2 corresponding to the regional color information that matches the preset color relationship is greater than the value of the adjustment weight WGT2 corresponding to the regional color information that does not conform to the preset color relationship. For example, in FIG. 4, the value (eg, 20 and 30) of the adjustment weight W1 corresponding to the area color information corresponding to the portrait FGR is larger than the adjustment weight (such as 10) corresponding to the area color information that does not correspond to the portrait FGR.

In an embodiment, the red color component R and the green color component in the complex color of the regional color information that meets the preset color relationship. The color components of the quantity G and blue correspond to the following relationship: R>1.1G>B.

In this operation example, the controller 120 may multiply the weight MGT in the photometry matrix MMX in FIG. 3C and the corresponding adjustment weight WGT2 in the adjustment matrix ADM2 to generate an adjusted photometry matrix. For related details, refer to the foregoing embodiments, and therefore, details are not described herein.

According to the adjusted photometry matrix, the controller 120 can calculate the current picture brightness value of the picture when the controller 120 can increase the weight of the portrait area. In this way, the correlation between the current picture brightness value of the picture and the portrait area in the picture can be improved.

Referring to Fig. 5, in an operation example, the aforementioned picture may include a high frequency region HFR. The image data of this screen may include a detail information of the screen. This detail includes a detailed information matrix. The detail information matrix includes a plurality of regional detail statistics. The regional detail statistics correspond to the multiple regions of the screen. The adjustment matrix ADM3 includes a plurality of adjustment weights WGT3. The adjustment weight WGT3 corresponds to the regional detail statistics.

In an embodiment, the region detail statistics represent the frequency of brightness changes of the regions in the corresponding picture. For example, the brightness of an area changes more frequently (this area corresponds to, for example, a small leaf, a character, a bar code, etc.), and the higher the corresponding area detail statistical value, the lower the brightness of an area changes (this area is for example Corresponding to the flat and monochromatic background, desktop, wall, etc., the lower the corresponding regional detail statistics. Therefore, in an embodiment, the controller 120 may determine the adjustment in the adjustment matrix ADM3 according to the regional detail statistics and a preset mode (eg, face mode, text mode, and two-dimensional code mode). The whole weight is WGT3.

Specifically, in an embodiment, in a case where the preset mode is a first mode (for example, a two-dimensional code mode), a value corresponding to the adjustment weight WGT3 corresponding to the higher region detail statistical value is greater than corresponding to The value of the adjustment weight WGT3 corresponding to the lower area detail statistics. For example, in FIG. 5, the value of the adjustment weight W1 corresponding to the region detail statistical value corresponding to the high frequency region HFR (such as 20 and 30) is larger than the adjustment weight corresponding to the region color information not corresponding to the high frequency region HFR. (eg 10).

On the other hand, in the case where the preset mode is a second mode (for example, a face mode), the value corresponding to the adjustment weight WGT3 corresponding to the higher region detail statistical value is lower than corresponding to having a lower region detail. The value of the adjustment weight corresponding to the statistical value WGT3.

In this operation example, the controller 120 may multiply the weight MGT in the photometric matrix MMX in FIG. 3C and the corresponding adjustment weight WGT3 in the adjustment matrix ADM3 to generate an adjusted photometry matrix. For related details, refer to the foregoing embodiments, and therefore, details are not described herein.

According to the adjusted photometric matrix, the controller 120 can calculate the current picture brightness value of the picture when the controller 120 can increase or decrease the weight of the high frequency or low frequency area. In this way, the correlation between the current picture brightness value of the picture and the theme in the picture can be improved.

It should be noted that in various embodiments, the controller 120 may simultaneously generate an adjusted photometric matrix according to any one, any two, or any combination of the photometric matrix MMX and the adjustment matrices ADM1-ADM3.

For example, all elements in the adjusted metering matrix can be metered All elements in the matrix MMX are generated by multiplying all elements in the adjustment matrix ADM1, all elements in the adjustment matrix ADM2, and all elements in the adjustment matrix ADM3. That is, the weighted value of the top left of the adjusted photometry matrix is 1*3*10*10=300, and the weight of the top right is 1*10*10*10=10000, and the weight at the bottom left is The value is 1*5*10*10=500, and the weight value at the bottom right is 1*3*10*10=300, and the most central weight is 10*10*20*30=6000.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and the present invention can be modified and retouched without departing from the spirit and scope of the present invention. The scope is subject to the definition of the scope of the patent application attached.

200‧‧‧ method

S1-S5‧‧‧ steps

Claims (7)

A method for calculating a brightness of a picture, comprising: obtaining an image data of a picture; generating at least one adjustment matrix according to the image data of the picture; generating an adjusted photometry matrix according to a photometry matrix and the adjustment matrix; The adjusted photometric matrix meters the picture to calculate a current picture brightness value of the picture; wherein the image data includes an initial brightness of the picture, the initial brightness includes a plurality of area brightness values, and the brightness of the areas The values respectively correspond to a plurality of regions of the screen, the adjustment matrix includes a plurality of adjustment weights, and the adjustment weights respectively correspond to the luminance values of the regions, and according to the image data of the screen, the step of generating the adjustment matrix comprises: The brightness relationship between the brightness values of the regions determines the adjustment weights; wherein the region brightness values include at least one extreme brightness value and a plurality of intermediate brightness values, wherein the adjustment weights correspond to the adjustment weights of the extreme brightness values The value is lower than the adjustment corresponding to the intermediate brightness values among the adjustment weights The weight of the value. The method for calculating the brightness of a picture according to claim 1, wherein a first extreme brightness value of the at least one extreme brightness value is smaller than the intermediate brightness values. A method for calculating a brightness of a picture, comprising: obtaining an image data of a picture; generating at least one adjustment matrix according to the image data of the picture; generating an adjusted photometry matrix according to a photometry matrix and the adjustment matrix; The adjusted photometric matrix meters the picture to calculate a current picture brightness value of the picture; wherein the image data includes a color information of the picture, the color information includes a plurality of regional color information, and the color of the areas The information is respectively corresponding to a plurality of regions of the screen, the adjustment matrix includes a plurality of adjustment weights, and the adjustment weights respectively correspond to the regional color information, and according to the image data of the screen, the step of generating the adjustment matrix comprises: The relationship between the plurality of colors in the regional color information determines the adjustment weights. The method for calculating the brightness of a picture according to claim 3, wherein the colors of a first one of the regional color information conform to a preset color relationship, and the second one of the plurality of regional color information The color does not match the preset color relationship, and the adjustment weight corresponding to the first one of the regional color information is greater than the second of the adjustment weights corresponding to the regional color information. The value of the adjustment weight. a method for calculating the brightness of a picture as described in claim 3, The determining the weights according to the relationship between the plurality of colors in each of the regional color information includes: determining, according to whether the colors in each of the regional color information meet a predetermined color relationship, The adjustment weights, wherein the red color component R, the green color component G, and the blue color component of the colors corresponding to the regional color information of the preset color relationship satisfy the following relationship: R>1.1G>B . A method for calculating a brightness of a picture, comprising: obtaining an image data of a picture; generating at least one adjustment matrix according to the image data of the picture; generating an adjusted photometry matrix according to a photometry matrix and the adjustment matrix; The adjusted photometric matrix meters the picture to calculate a current picture brightness value of the picture; wherein the image data includes a detail information of the picture, the detail information includes a plurality of area detail statistics, the areas The detail statistics respectively correspond to a plurality of regions of the screen, the adjustment matrix includes a plurality of adjustment weights, and the adjustment weights respectively correspond to the regional detail statistics, and according to the image data of the screen, the step of generating the adjustment matrix includes : determining the adjustment weights according to the regional detailed statistics and a preset mode. The method for calculating the brightness of the picture according to claim 6, wherein the area detail statistics include a first detail value and a second detail value, the first detail value being greater than the second detail value, in the preset mode In the case of a first mode, the value of the adjustment weight corresponding to the first detail value among the adjustment weights is higher than the value of the adjustment weight corresponding to the second detail value among the adjustment weights, and in the pre- In the case that the mode is a second mode, the value of the adjustment weight corresponding to the first detail value among the adjustment weights is lower than the value of the adjustment weight corresponding to the second detail value among the adjustment weights.