TWI382745B - Image capturing device and setting unit and method for gaining tables thereof - Google Patents

Description

Image capturing device and gain table establishing unit and establishing method thereof

The present invention relates to an image processing technology, and more particularly to a gain form establishing unit and an establishing method, and an image capturing device having the gain form establishing unit.

At present, the lens used in the image capturing device on the market is not uniform. Some lenses may differ in the brightness ratio between the center and the periphery of the lens after leaving the factory, which causes the peripheral transmittance of some lenses to be low, and the image is sensitive. When the periphery is not able to obtain the brightness corresponding to the center, usually the middle is bright and the dark is dark, which is the lens shadowing effect, which will have a certain impact on the image quality.

In view of this, the present invention provides a gain form establishing unit and a setting method capable of establishing a gain form for compensating a lens shading effect on an image. The present invention also provides an image capturing device having the gain form establishing unit, which can call the gain form to compensate for a lens shading effect of an image acquired by the image capturing device, thereby ensuring image quality.

A gain form establishing unit is configured to establish a gain form to compensate for the first original image and the second original image acquired by the image capturing device. The gain form establishing unit includes a region dividing subunit, an average calculating subunit, a selecting subunit, and a gain calculating subunit. The area dividing subunit is configured to divide the first original image into a plurality of first sub-areas. The average calculation subunit is configured to respectively calculate a first red average luminance value, a first green average luminance value, and a first blue average luminance value of each first subregion pixel of the first original image. The selecting subunit is configured to select a maximum red average luminance value from the plurality of first red average luminance values, and select a largest green average luminance value from the plurality of first green average luminance values, from the The largest blue average luminance value is selected among the plurality of first blue average luminance values. The gain calculation sub-unit calculates a red luminance gain of each first sub-region according to the maximum red average luminance value and the first red average luminance value of each of the first sub-region pixels to obtain a red channel a luminance gain form, calculating a green luminance gain of each first sub-region according to the maximum green average luminance value and a first green average luminance value of each of the first sub-region pixels to obtain a luminance gain of the green channel Form, according to the maximum blue average luminance value and the first blue average luminance value of each of the first sub-region pixels, calculate a blue luminance gain of each first sub-region to obtain a blue channel a luminance gain form, and outputting a luminance gain form of the red channel, a luminance gain form of the green channel, and a luminance gain form of the blue channel to the image capturing device for the image capturing device to call The second original image is compensated.

A gain form establishing method, comprising the steps of: acquiring a first original image; dividing the first original image into a plurality of first sub-regions; respectively calculating each first of the first original images a first red average luminance value, a first green average luminance value, and a first blue average luminance value of the sub-region pixels; a maximum red average luminance value is selected from the plurality of first red average luminance values, from the plurality of Selecting a maximum green average luminance value from the first green average luminance values, and selecting a largest blue average luminance value from the plurality of first blue average luminance values; and according to the maximum red average luminance value and each of the a first red average luminance value of the first sub-region pixels, and calculating a red luminance gain of each of the first sub-regions, according to the maximum green average luminance value and the first green average of each of the first sub-region pixels a luminance value, calculating a green luminance gain of each of the first sub-regions, and calculating, according to the maximum blue average luminance value and the first blue average luminance value of each of the first sub-region pixels a blue luminance gain of each of the first sub-regions; a luminance gain form of the red channel, a luminance gain form of the green channel, and a luminance gain form of the blue channel according to the red luminance gain, the green luminance gain, and the blue luminance gain, respectively And outputting a luminance gain form of the red channel, a luminance gain form of the green channel, and a luminance gain form of the blue channel to the image capturing device for the image capturing device to call.

An image capture device having a gain form creation unit as described above, comprising an image acquisition unit, a storage unit and a central processing unit. The image acquisition unit is configured to acquire the first original image and the second original image. The storage unit is configured to store a luminance gain form of the red channel, a luminance gain form of the green channel, and a luminance gain form of the blue channel, which are output from the gain form establishing unit. The central processing unit divides the second original image into a plurality of second sub-regions that are consistent with the first sub-region of the first original image segmentation in the same division form as the region dividing sub-unit, Calculating a second red average luminance value, a second green average luminance value, and a second blue average luminance value of each second sub-region pixel of the second original image, respectively, and calling the red channel luminance gain form a luminance gain form of the green channel and a luminance gain form of the blue channel, multiplying a red luminance gain in the red channel luminance gain form by a corresponding second red average luminance value of each of the second sub-region pixels Performing red channel luminance compensation, multiplying the green luminance gain in the green channel luminance gain form by the corresponding second green average luminance value of each of the second sub-region pixels to perform green channel luminance compensation, and the blue The blue luminance gain in the color channel luminance gain form is multiplied by the corresponding second blue average luminance value of each of the second sub-region pixels to perform blue pass Luminance compensation.

Compared with the prior art, the image capturing device and the gain form establishing unit and the establishing method thereof use the red luminance gain, the green luminance gain, and the blue for calculating the first sub-region of the first original image. The luminance gain forms a luminance gain form of the red channel, a luminance gain form of the green channel, and a luminance gain form of the blue channel, respectively, for the image capturing device to call the above form each time the image capturing device acquires the image and complement the image luminance Reimbursement, thereby compensating for the lens shading effect and ensuring image quality.

The invention will be further described in detail below with reference to the accompanying drawings.

Please refer to FIG. 1 , which is a gain form establishing unit 10 for establishing a gain form to compensate for a first original image and a second image acquired by the image capturing device 20 (shown in FIG. 4 ) due to lens quality reasons. The shadowing effect caused by the original image.

The gain form establishing unit 10 includes a region dividing sub-unit 12, an average calculating sub-unit 14, a selecting sub-unit 16, a gain calculating sub-unit 18, and a comparing sub-unit 19.

The area dividing sub-unit 12 is configured to divide the first original image into a plurality of first sub-areas, which are n in the embodiment.

The average value calculation sub-unit 14 is configured to respectively calculate a first red average luminance value R _i , a first green average luminance value G _{i ,} and a first blue of each first sub-region pixel of the first original image. The color average luminance value B _i (i = 1, ... n).

The selecting subunit 16 is configured to select a largest red average luminance value R _max from the plurality of first red average luminance values R _i , and select a largest green color from the plurality of first green average luminance values G _i The average luminance value G _{max is} selected from the plurality of first blue average luminance values B _i and the largest blue average luminance value B _max .

The gain calculation sub-unit 18 is configured to respectively calculate a red luminance gain K _ri of each first sub-region to obtain a luminance gain form of the red channel, and a green luminance gain K _{gi of} each first sub-region to obtain a green color The luminance gain form of the channel, the blue luminance gain K _{bi of} each first sub-region to derive the luminance gain form of the blue channel. The gain calculation sub-unit 18 outputs a luminance gain form of the red channel, a luminance gain form of the green channel, and a luminance gain form of the blue channel to the image capturing device 20 (shown in FIG. 4) for the image. The capture device 20 (shown in Figure 4) invokes compensation for the second original image.

The comparison subunit 19 is pre-set with a gain range for comparing whether the gains K _ri , K _gi , and K _bi are within a preset gain range, if the red luminance gain, the green luminance gain, and the blue luminance gain Outputting a gain form to form a signal within a preset gain range, and outputting a clean image capture device lens and image sense if any of the red luminance gain, the green luminance gain, and the blue luminance gain are not within the preset gain range Measuring component signals. In order to ensure that the gain does not cause excessive noise to the image acquired by the image capturing device 20 (shown in FIG. 4), the preset gain range in the present embodiment is preferably 1-2. Therefore 1≦K _ri ≦2,1≦K _gi ≦2,1≦K _bi ≦2. If any of K _ri , K _gi , and K _bi exceeds 2, it indicates that the lens of the image capturing device 20 (shown in FIG. 4 ) is not clean or the image sensing component is not clean and needs to be cleaned.

Referring to FIG. 2, a method for establishing a gain form according to the present invention includes the following steps: S100: Acquire a first original image.

S102: Divide the first original image into a plurality of first sub-regions.

S104: Calculate, respectively, a first red average luminance value R _i , a first green average luminance value G _{i ,} and a first blue average luminance value B _i of each first sub-region pixel of the first original image.

S106: Select a maximum red average luminance value R _max , a maximum green average luminance value G _{max ,} and a maximum blue average luminance value B _max from the values of R _i , G _i , and B _i , and calculate each first sub-child The red luminance gain K _ri , the green luminance gain K _{gi ,} and the blue luminance gain K _{bi of the} region. Where K _ri = R _max /R _i , K _gi =G _max /G _i , K _bi =B _max /B _i .

S108: Compare whether the gains K _ri , K _gi , and K _bi are within a preset gain range. If any of the gains K _ri , K _gi , and K _{bi are} not within the preset gain range, proceed to step S114: clean the image capturing device lens and the image sensing element, and then return to step S100 if the gains K _ri , K _gi If the K _bi is within the preset gain range, proceed to step S110: forming a luminance gain form of the red channel, a luminance gain form of the green channel, and a luminance gain of the blue channel according to the gains K _ri , K _gi , and K _bi , respectively. Form.

S112: Output a luminance gain form of the red channel, a luminance gain form of the green channel, and a luminance gain form of the blue channel to the image capturing device.

To clearly illustrate the present invention provides a form of gain establishment method, see Figure 3, after first obtaining an original image I divided into a first sub-region ₁₁ to six I _23, I ₁₁ sequentially calculated to six I ₂₃ The first red average luminance values R ₁ to R ₆ , the first green average luminance values G ₁ to G _{6 ,} and the first blue average luminance values B ₁ to B _{6 of the} first sub-region pixels. Select the largest red average luminance value from R ₁ to R ₆ , select the largest green average luminance value from G ₁ to G ₆ , and select the largest blue average luminance value from B ₁ to B ₆ , for example, R respectively. ₃ , G3, B ₃ . Then, the luminance gains of the red channels of the six first sub-regions are respectively K _r1 =R ₃ /R ₁ , K _r2 =R ₃ /R ₂ , K _r3 =R ₃ /R ₃ , K _r4 =R ₃ /R ₄ , K _r5 = R ₃ / R ₅ , K _r6 = R ₃ / R ₆ . The luminance gain of the green channel is K _g1 =G ₃ /G ₁ , K _g2 =G ₃ /G ₂ , K _g3 =G ₃ /G ₃ , K _g4 =G ₃ /G ₄ , K _g5 =G ₃ /G ₅ , K _g6 = G ₃ / G ₆ . The luminance gain of the blue channel is K _b1 =B ₃ /B ₁ , K _b2 =B ₃ /B ₂ , K _b3 =B ₃ /B ₃ , K _b4 =B ₃ /B ₄ , K _b5 =B ₃ / B ₅ , K _b6 =B ₃ /B ₆ . See Table 1 for details.

Referring to FIG. 4, an image capturing device 20 according to the present invention includes an image capturing unit 22, a storage unit 24, a central processing unit 26, and a gain form establishing unit 10 as described above. The image acquiring unit 22 is configured to acquire the first original image and the second original image. The storage unit 24 is configured to store a luminance gain form of the red channel, a luminance gain form of the green channel, and a luminance gain form of the blue channel, which are output from the gain form establishing unit 10. The central processing unit 26 divides the second original image into a plurality of second sub-segments consistent with the first sub-region of the first original image division in the same division form as the region division sub-unit 12 a region, respectively calculating a second red average luminance value R _i ', a second green average luminance value G _i ', and a second blue average luminance value B _i of each second sub-region pixel of the second original image ', calling the luminance gain form of the red channel, the luminance gain form of the green channel, and the luminance gain form of the blue channel, multiplying the red luminance gain K _ri in the luminance gain form of the red channel by the corresponding each a second red average luminance value R _i ' of the second sub-region pixels for performing red channel luminance compensation, multiplying the green luminance gain K _gi in the luminance gain form of the green channel by the corresponding each of the second sub-pixels second green region pixel average luminance value of G _i 'for green channel compensation luminance, the luminance of the blue luminance gain K _bi form the blue channel gain is multiplied by the second sub-region corresponding to each of the image A second average luminance value of the blue color B _i 'for a blue channel luminance compensation.

Please refer to FIG. 5 , which is a flowchart of the step of the image capturing device 20 in the present invention for compensating the second original image by using the gain form: S116: acquiring the second original image.

S118: The second original image is divided into a plurality of second sub-regions that are consistent with the first sub-region of the first original image segmentation in the same division form as the region dividing sub-unit 12.

S120: respectively calculate a second red average luminance value R _i ', a second green average luminance value G _i ', and a second blue average luminance value B _i of each second sub-region pixel of the second original image. ', call the red channel's luminance gain form, the green channel's luminance gain form, and the blue channel's luminance gain form for three-channel luminance compensation. The specific compensation manner is as follows: multiplying the red luminance gain K _ri in the luminance gain form of the red channel by the corresponding second red average luminance value R _i ' of each of the second sub-region pixels to perform a red channel Brightness compensation. Multiplying the green luminance gain K _gi in the luminance gain form of the green channel by the corresponding second green average luminance value G _i ' of each of the second sub-region pixels to perform green channel luminance compensation. Multiplying the blue luminance gain K _b in the luminance gain form of the blue channel by the corresponding second blue average luminance value B _i ' of each of the second sub-region pixels to perform blue channel luminance compensation.

The image capturing device and the gain form establishing unit and the establishing method thereof are respectively configured to calculate a red luminance gain, a green luminance gain, and a blue luminance gain of each first sub-region of the first original image. The luminance gain form of the red channel, the luminance gain form of the green channel, and the luminance gain form of the blue channel, for the image capturing device to call the above form each time the image capturing device acquires the image to compensate for the image luminance compensation Lens shadowing effect to ensure image quality.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only the preferred embodiment of the present invention, and equivalent modifications or variations made by the person skilled in the art of the present invention should be included in the following claims.

Gain form creation unit. . . 10

Area division subunit. . . 12

Average calculation subunit. . . 14

Select the subunit. . . 16

Gain calculation subunit. . . 18

Compare subunits. . . 19

Image capture device. . . 20

Image acquisition unit. . . twenty two

Storage unit. . . twenty four

Central processing unit. . . 26

1 is a block diagram of a gain form building unit of the present invention.

2 is a flow chart showing the steps of a method for establishing a gain form according to the present invention.

FIG. 3 is a schematic diagram of the image obtained by the gain form establishing unit of FIG. 1. FIG.

4 is a block diagram of an image capturing device of the present invention.

FIG. 5 is a flow chart showing the steps of the image capturing device calling the gain form according to the present invention.

Gain form creation unit. . . 10

Area division subunit. . . 12

Average calculation subunit. . . 14

Select the subunit. . . 16

Gain calculation subunit. . . 18

Compare subunits. . . 19

Claims (5)

A gain form establishing unit is configured to establish a gain form to compensate a first original image and a second original image acquired by the image capturing device, the gain form establishing unit comprising: a region dividing subunit, configured to: Dividing the first original image into a plurality of first sub-regions; an average value calculation sub-unit for respectively calculating a first red average of each of the first sub-region pixels of the first original image a luminance value, a first green average luminance value, and a first blue average luminance value; a selection subunit configured to select a maximum red average luminance value from the plurality of first red average luminance values, from the plurality of Selecting a maximum green average luminance value from the first green average luminance values, selecting a largest blue average luminance value from the plurality of first blue average luminance values, and a gain calculation subunit for a maximum red average luminance value and a first red average luminance value of each of the first sub-region pixels, and calculating a red luminance gain of each of the first sub-regions to obtain a red channel luminance a gain form, calculating a green luminance gain of each first sub-region according to the maximum green average luminance value and a first green average luminance value of each of the first sub-region pixels to obtain a luminance gain form of the green channel Calculating a blue luminance gain of each first sub-region according to the maximum blue average luminance value and a first blue average luminance value of each of the first sub-region pixels to obtain a luminance of the blue channel a gain form, and outputting a luminance gain form of the red channel, a luminance gain form of the green channel, and a luminance gain form of the blue channel to the image capturing device for the image capturing device to call The two original images are compensated. The gain form establishing unit according to claim 1, wherein the gain form establishing unit further comprises a comparing subunit, wherein a gain range is pre-set, and the comparing subunit is configured to compare each of the Whether the red luminance gain of the first sub-region is within a preset gain range, whether the green luminance gain of each first sub-region is within a preset gain range, and whether the blue luminance gain of each first sub-region is in advance If the red luminance gain, the green luminance gain, and the blue luminance gain are within the preset gain range, a gain form is formed to form a signal, if the red luminance gain, the green luminance gain, and the blue luminance gain are not selected. A clean image capture device lens and image sensing component signal are output within a preset gain range. An image capture device having a gain form creation unit according to claim 1 of the patent application, comprising an image acquisition unit, a storage unit and a central processing unit, wherein the image acquisition unit is configured to acquire the first original An image and the second original image, the storage unit is configured to store a luminance gain form of the red channel outputted from the gain form establishing unit, a luminance gain form of the green channel, and a luminance gain form of the blue channel The central processing unit divides the second original image into a plurality of second sub-regions that are consistent with the first sub-region of the first original image division by using the same division manner as the region division sub-unit Calculating a second red average luminance value, a second green average luminance value, and a second blue average luminance value of each second sub-region pixel of the second original image, respectively, and calling the luminance gain of the red channel The form, the luminance gain form of the green channel, and the luminance gain form of the blue channel, the red in the luminance gain form of the red channel The luminance gain is multiplied by a second red average luminance value of each second sub-region pixel of the corresponding second original image to perform red channel luminance compensation, and the green luminance gain in the luminance gain form of the green channel is multiplied Multiplying the blue luminance gain in the luminance gain form of the blue channel by the second green average luminance value of each second sub-region pixel of the corresponding second original image to perform green channel luminance compensation Corresponding a second blue average luminance value of each second sub-region pixel of the second original image to perform blue channel luminance compensation. A gain form establishing method, the gain form establishing method comprising: acquiring a first original image; dividing the first original image into a plurality of first sub-regions; respectively calculating the first original image a first red average luminance value, a first green average luminance value, and a first blue average luminance value of each of the first sub-region pixels; and a maximum red average luminance value from the plurality of first red average luminance values And selecting a largest green average luminance value from the plurality of first green average luminance values, and selecting a largest blue average luminance value from the plurality of first blue average luminance values; according to the maximum red average luminance Calculating a red luminance gain of each first sub-region according to the value and the first red average luminance value of each of the first sub-region pixels, according to the maximum green average luminance value and each of the first sub-region pixels a first green average luminance value, and calculating a green luminance gain of each of the first sub-regions, according to the maximum blue average luminance value and the first blue of each of the first sub-region pixels The average luminance value is calculated, and the blue luminance gain of each first sub-region is calculated; the luminance gain form of the red channel, the luminance gain form of the green channel, and the blue are respectively formed according to the red luminance gain, the green luminance gain, and the blue luminance gain a luminance gain form of the color channel; and a luminance gain form for outputting the red channel, a luminance gain form of the green channel, and a luminance gain form of the blue channel to the image capturing device for the image capturing device to call. The gain form establishing method according to claim 4, wherein a comparison step is further included between the luminance gain calculating step and the gain form forming step: comparing the red of each of the first sub-regions Whether the luminance gain is within a preset gain range, whether the green luminance gain of each first sub-region is within a preset gain range, and whether the blue luminance gain of each first sub-region is within a preset gain range, if red The luminance gain, the green luminance gain, and the blue luminance gain all output a gain form to form a signal within a preset gain range, and if any of the red luminance gain, the green luminance gain, and the blue luminance gain is not within the preset gain range, Output a clean image capture device lens and image sensing component signal.