CN101141656A - Image processing apparatus and method thereof - Google Patents

Abstract

The present invention discloses an image processing device, which is used to adjust the brightness of an inputted image. The inputted image has a color hue. The image processing device comprises a comparison table, a processing unit and an adder, wherein, the comparison table is used to record the brightness with the quantity of M, the color hue with the quantity of N and the correspondent brightness compensation value with the quantity of M is multiplied by N. The processing unit is used to store the comparison table, and decides the correspondent brightness compensation value according to the comparison table, the brightness and the color hue. The adder is coupled with the processing unit, and is used to add the brightness of the inputted image and the correspondent brightness compensation value, to get the adjusted brightness. Thereby, the image quality can be advanced.

Description

Image processing apparatus and method thereof

Technical field

The invention relates to a kind of image processing apparatus and method thereof, and, and adjust the image processing apparatus and the method thereof of saturation according to adjusted brightness particularly relevant for a kind of brightness (Lightness) of adjusting input picture (Input image).

Background technology

In present display, the user all can pass through window picture operating system, and (On screendisplay OSD) adjusts the saturation of color, to strengthen the display effect of image.See also Fig. 1 to Fig. 2 B, Fig. 1 is the functional block diagram that illustrates the image processing apparatus 1 of prior art.Fig. 2 A is the schematic diagram that illustrates luminance gain value table of comparisons 160a among Fig. 1.Fig. 2 B is the schematic diagram that illustrates tone yield value table of comparisons 160b among Fig. 1.Image processing apparatus 1 comprises first color space converter 10, tone transducer 12, the first saturation transducer 14, processing unit 16a, 16b, multiplier 18a, 18b, the second saturation transducer 20 and second color space converter 22.Processing unit 16a can store luminance gain value table of comparisons 160a, and shown in Fig. 2 A, and processing unit 16b can store tone yield value table of comparisons 160b, shown in Fig. 2 B.

First color space converter 10 is in order to be converted to the Lab color space with input picture by rgb color space, and wherein L is a luminance elements, and a and b are respectively color element.(Hue, H), wherein tone H is defined as tone transducer 12 in order to the tone that color element a and b is converted to input picture $H={\tan }^{-1}\left(\frac{b}{a}\right).$ (Saturation, S), wherein saturation S is defined as the first saturation transducer 14 in order to the saturation that color element a and b is converted to input picture $S=\sqrt{a^2+{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="A20061015130800121.png"\; state="\{\{state\}\}">b</figure-callout>}}^2}.$

Processing unit 16a is according to the brightness (Lightness of input picture, L) and luminance gain value table of comparisons 160a, and determine luminance gain value Gain-L, and processing unit 16b is according to the tone and the tone yield value table of comparisons 160b of input picture, and determine tone yield value Gain-H.Then, multiplier 18a can multiply by luminance gain value Gain-L tone yield value Gain-H, to produce saturation yield value Gain-S.Afterwards, multiplier 18b multiply by saturation yield value Gain-S the saturation of input picture again, to produce adjusted saturation.

The second saturation transducer 20 is in order to being converted to color element a and b with adjusted saturation, and second color space converter 22 is converted to rgb color space with input picture by the Lab color space again.

See also Fig. 3 A and Fig. 3 B, Fig. 3 A is the schematic diagram that illustrates the Lab color space.Fig. 3 B illustrates in the Lab color space schematic diagram of the saturation of different brightness and tone thereof.As shown in Figure 3A, in the Lab color space, brightness L is by highly control, and tone H is by angle control, and saturation S is controlled by radius.According to above-mentioned, the image processing apparatus 1 of prior art is to utilize luminance gain value Gain-L and tone yield value Gain-H to adjust the saturation of input picture respectively.Yet, shown in Fig. 3 B, when the brightness of input picture not simultaneously, the saturation scope of its tone is also different.Because the color space tangent plane difference of each brightness, and different tones (angle) have different saturation scopes, so choose luminance gain value Gain-L according to different brightness, and choose tone yield value Gain-H according to different tones, can cause saturation control to be difficult for, and then cause color to depart from.

In addition, the image processing apparatus 1 of prior art is that the user does not have the hobby of way along with oneself, increases or reduce brightness in order to the adjustment saturation.

Therefore, category of the present invention is to provide a kind of image processing apparatus and method thereof, to address the above problem.

Summary of the invention

One of category of the present invention is to provide a kind of image processing apparatus and method thereof, and this image processing apparatus according to the brightness and the tone of input picture, is adjusted the brightness of input picture simultaneously.By this, can obtain preferable picture quality.

According to a preferred embodiment, image processing apparatus of the present invention (Image processingapparatus) is in order to adjusting the brightness (Lightness) of input picture (Input image), input picture and comprise tone (Hue).This image processing apparatus comprises the table of comparisons (Look-up table), processing unit (Processing unit) and adder (Adder).

In the above embodiments, the table of comparisons is in order to record M brightness, a N tone and M*N luminance compensation value (Lightness offset value), and each M*N luminance compensation value corresponds respectively to one of them of M brightness and one of them of N tone, and wherein M and N are all natural number.Processing unit is in order to storing the table of comparisons, and determines the corresponding brightness offset according to brightness, tone and the table of comparisons of input picture.And adder is to couple mutually with processing unit, and in order to brightness and the addition of corresponding brightness offset with input picture, adjusts back brightness and draw.

Therefore, image processing apparatus of the present invention is the brightness of adjusting input picture according to the brightness and the tone of input picture simultaneously, and then increases the brightness adjustment of the color of input picture.By this, can obtain preferable picture quality.

The present invention also provides a kind of image processing method, in order to adjust the brightness of input picture, this input picture and comprise tone, this image processing method comprises the following step: (a) according to the table of comparisons, this brightness and this tone, decision corresponding brightness offset, wherein this table of comparisons is in order to record M brightness, a N tone and M*N luminance compensation value, and each this M*N luminance compensation value corresponds respectively to one of them of this M brightness and one of them of this N tone, and wherein M and N are all natural number; And, adjust back brightness and draw (b) with this brightness and this corresponding brightness offset addition of this input picture.

Can be about the advantages and spirit of the present invention by following detailed Description Of The Invention and appended graphic being further understood.

Description of drawings

Fig. 1 is the functional block diagram that illustrates the image processing apparatus of prior art.

Fig. 2 A is the schematic diagram that illustrates the luminance gain value table of comparisons among Fig. 1.

Fig. 2 B is the schematic diagram that illustrates the tone yield value table of comparisons among Fig. 1.

Fig. 3 A is the schematic diagram that illustrates the Lab color space.

Fig. 3 B illustrates in the Lab color space schematic diagram of the saturation of different brightness and tone thereof.

Fig. 4 is the functional block diagram that illustrates the image processing apparatus of first preferred embodiment according to the present invention.

Fig. 5 is the schematic diagram that illustrates the table of comparisons among Fig. 4.

Fig. 6 is the flow chart of the image processing method of first preferred embodiment according to the present invention.

Fig. 7 is the schematic diagram that illustrates the table of comparisons of second preferred embodiment according to the present invention.

[main element label declaration]

1,3: image processing apparatus 10,22: color space converter

12: tone transducer 14,20: saturation transducer

16a, 16b: processing unit 160a: the luminance gain value table of comparisons

160b: tone yield value table of comparisons 18a, 18b: multiplier

30,32,34,40,42: transducer 36: processing unit

38: adder

360,360 ': the table of comparisons 44: saturation adjustment unit

5: input picture L: brightness

H: tone S: saturation

C1, C2: color element S100-S110: process step

Embodiment

See also Fig. 4, Fig. 4 is the functional block diagram that illustrates the image processing apparatus 3 of first preferred embodiment according to the present invention.In this embodiment, image processing apparatus (Image processingapparatus) 3 in order to the brightness of adjusting input picture (Input image) 5 (Lightness, L), input picture and have saturation (Saturation, S) and tone (Hue, H).In this embodiment, input picture 5 is to meet rgb color space (first color space).

As shown in Figure 4, image processing apparatus 3 comprises first transducer (Converter) 30, second transducer 32, the 3rd transducer 34, processing unit (Processing unit) 36, adder (Adder) 38, the 4th transducer 40, the 5th transducer 42 and saturation adjustment unit 44.Wherein, processing unit 36 can store the table of comparisons (Look-up table) 360, in order to record M brightness, a N tone and M*N luminance compensation value (Lightness offset value), and each M*N luminance compensation value corresponds respectively to one of them of M brightness and one of them of N tone, and wherein M and N are all natural number.First transducer 30 couples mutually with processing unit 36.Second transducer 32 is coupled between first transducer 30 and the processing unit 36.The 3rd transducer 34 is coupled to first transducer 30.Saturation adjustment unit 44 is coupled to second transducer 32, the 3rd transducer 34 and adder 38.The 4th transducer 40 couples mutually with saturation adjustment unit 44.The 5th transducer 42 couples mutually with the 4th transducer 40 and adder 38 respectively.

See also Fig. 5, Fig. 5 is the schematic diagram that illustrates the table of comparisons 360 among Fig. 4.In the first above-mentioned embodiment, and M brightness of the table of comparisons 360 record (L1～LM), a N tone (H1～HN) and M*N luminance compensation value (L_off_11～L_off_NM), as shown in Figure 5.Be noted that the table of comparisons 360 can be according to different demands, and do different settings.Each the luminance compensation value that is recorded in the table of comparisons 360 can be obtained by software emulation, does not repeat them here.

In the first above-mentioned embodiment, first transducer 30 is in order to be converted to input picture 5 second color space of brightness and color-separated by rgb color space (first color space), wherein, second color space is to be selected from one of them of following group: YCbCr, Yuv, YIQ, CIELab and Luv color space, and second color space definition luminance elements L and color element C1, C2.Second transducer 32 is in order to be converted to tone H with color element C1 and C2, and wherein tone H is defined as H=tan ^-1(C1/C2).The 3rd transducer 34 is in order to be converted to saturation S with color element C1 and C2, and wherein saturation S is defined as $S=\sqrt{{\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="A20061015130800111.png,A20061015130800121.png"\; state="\{\{state\}\}">C</figure-callout>}1}^2+{\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="A20061015130800121.png"\; state="\{\{state\}\}">C</figure-callout>}2}^2}.$ Processing unit 36 according to the brightness L of input picture 5,

The tone H and the table of comparisons 360 and determine the corresponding brightness offset.For example, if the brightness value of input picture 5 is that L3 and tone value are H3, then processing unit 36 can determine corresponding luminance compensation value L_off_33 according to the table of comparisons 360.Afterwards, adder 38 can be adjusted back brightness and draw with the brightness and the addition of corresponding brightness offset of input picture 5.By this, the brightness of input picture is promptly simultaneously finished adjustment according to the brightness and the tone of input picture.

Afterwards, saturation adjustment unit 44 can be adjusted saturation according to adjusting back brightness and tone, adjusts the back saturation and draw.The 4th transducer 40 will be adjusted the back degree of saturation and be converted to color element C1 and C2.At last, the 5th transducer 42 is converted to first color space (as rgb color space) with input picture 5 by second color space (as YCbCr, Yuv, YIQ, CIELab or Luv color space) again.By this, the saturation of input picture is promptly simultaneously finished adjustment according to adjusted brightness and tone.

See also Fig. 6, Fig. 6 is the flow chart of the image processing method of first preferred embodiment according to the present invention.See also Fig. 4 and Fig. 5, image processing method of the present invention is in order to adjusting the brightness of input picture, input picture and have saturation and tone.According to the first above-mentioned preferred embodiment, image processing method of the present invention comprises the following step:

Step S100: input picture 5 is converted to second color space (as YCbCr, Yuv, YIQ, CIELab or Luv color space) by first color space (as rgb color space);

Step S102: according to the table of comparisons 360, brightness L and tone H, decision corresponding brightness offset;

Step S104:, adjust back brightness and draw with the brightness L and the addition of corresponding brightness offset of input picture 5;

Step S106: according to adjusting back brightness and tone, adjust saturation, adjust the back saturation and draw;

Step S108: will adjust the back saturation and be converted to color element C1 and C2;

Step S110: input picture 5 is converted to first color space by second color space.

See also Fig. 7, Fig. 7 be the table of comparisons 360 that illustrates second preferred embodiment according to the present invention ' schematic diagram.The table of comparisons 360 ' with the table of comparisons 360 main difference parts be to be recorded in the table of comparisons 360 ' in each illuminometer be shown brightness range, and each hue table is shown tone range.As shown in Figure 7, the table of comparisons 360 ' 10 brightness ranges of record, 18 tone ranges and 10*18 luminance compensation value.For example, if the brightness value of input picture 5 be 45 and tone value be 30, then processing unit 36 can according to the table of comparisons 360 ', determine corresponding luminance compensation value L_off_25.Be noted that brightness range, tone range and the luminance compensation value of the table of comparisons 360 ' write down can be according to different demands, and do different settings.

Compared to Prior Art, image processing apparatus of the present invention is the brightness of adjusting input picture according to the brightness and the tone of input picture simultaneously, and then increases the brightness adjustment of the color of input picture.By this, can obtain preferable picture quality.In addition, in the present invention,, make that the color adjustment of input picture is more flexible, cause picture quality to promote more because saturation is to adjust according to adjusted brightness.

By the above detailed description of preferred embodiments, be to wish to know more to describe feature of the present invention and spirit, and be not to come category of the present invention is limited with above-mentioned disclosed preferred embodiment.On the contrary, its objective is that hope can contain in the category of claim scope of being arranged in of various changes and tool equality institute of the present invention desire application.Therefore, the category of the claim scope that the present invention applied for should be done the broadest explanation according to above-mentioned explanation, contains the arrangement of all possible change and tool equality to cause it.

Claims (20)

1. image processing apparatus, in order to adjusting the brightness of input picture, this input picture and comprise tone, this image processing apparatus comprises:

The table of comparisons, in order to record M brightness, a N tone and M*N luminance compensation value, and each this M*N luminance compensation value corresponds respectively to one of them of this M brightness and one of them of this N tone, and wherein M and N are all natural number;

Processing unit in order to storing this table of comparisons, and determines the corresponding brightness offset according to this brightness, this tone and this table of comparisons of this input picture; And

Adder couples mutually with this processing unit, and this adder is adjusted back brightness in order to this brightness and this corresponding brightness offset addition with this input picture and draw.

2. image processing apparatus according to claim 1, each this M illuminometer that wherein is recorded in this table of comparisons is shown brightness range, and each this N hue table is shown tone range.

3. image processing apparatus according to claim 1, also comprise first transducer, couple mutually with this processing unit, this input picture meets first color space, this first transducer is in order to be converted to second color space with this input picture by this first color space, and wherein this second color space defines luminance elements L and two color element C1, C2.

4. image processing apparatus according to claim 3, wherein this first color space is a rgb color space.

5. image processing apparatus according to claim 3, wherein this second color space is to be selected from one of them of following group: YCbCr, Yuv, YIQ, CIELab and Luv color space.

6. image processing apparatus according to claim 3, also comprise second transducer, be coupled between this first transducer and this processing unit, this second transducer is in order to be converted to this tone with this two color elements C1 and C2, and wherein this tone H is defined as follows:

$H={\tan }^{-1}\left(\frac{C1}{C2}\right).$

7. image processing apparatus according to claim 3 also comprises the 3rd transducer, is coupled to this first transducer, and the 3rd transducer is in order to be converted to this two color elements C1 and C2 the saturation of this input picture, and wherein this saturation S is defined as follows:

$S=\sqrt{{C1}^2+{C2}^2}.$

8. image processing apparatus according to claim 7, also comprise the saturation adjustment unit, be coupled to this second transducer, the 3rd transducer and this adder, this saturation adjustment unit is in order to adjust back brightness and this tone according to this, adjust this saturation, adjust the back saturation and draw.

9. image processing apparatus according to claim 8 also comprises the 4th transducer, couples mutually with this saturation adjustment unit, and the 4th transducer was converted to this two color elements C1 and C2 in order to should adjust the back saturation.

10. image processing apparatus according to claim 9 also comprises the 5th transducer, couples mutually with the 4th transducer and this adder respectively, and the 5th transducer is in order to be converted to this first color space with this input picture by this second color space.

11. an image processing method, in order to adjusting the brightness of input picture, this input picture and comprise tone, this image processing method comprises the following step:

(a) according to the table of comparisons, this brightness and this tone, decision corresponding brightness offset, wherein this table of comparisons is in order to record M brightness, a N tone and M*N luminance compensation value, and each this M*N luminance compensation value corresponds respectively to one of them of this M brightness and one of them of this N tone, and wherein M and N are all natural number; And

(b) with this brightness and this corresponding brightness offset addition of this input picture, adjust back brightness and draw.

12. image processing method according to claim 11, each this M illuminometer that wherein is recorded in this table of comparisons is shown brightness range, and each this N hue table is shown tone range.

13. image processing method according to claim 11 also comprises the following step:

In step (a) before, earlier this input picture is converted to second color space by first color space, wherein this second color space defines a luminance elements L and two color element C1, C2.

14. method according to claim 13, wherein this first color space is a rgb color space.

15. method according to claim 13, wherein this second color space is to be selected from one of them of following group: YCbCr, Yuv, YIQ, CIELab and Luv color space.

16. image processing method according to claim 13, wherein according to this two color elements C1 and C2, this tone H is defined as follows:

$H={\tan }^{-1}\left(\frac{C1}{C2}\right).$

17. image processing method according to claim 13, wherein according to this two color elements C1 and C2, the saturation S of this input picture is defined as follows:

$S=\sqrt{{C1}^2+{C2}^2}.$

18. image processing method according to claim 17 also comprises the following step: (c), adjust this saturation, adjust the back saturation and draw according to this adjustment back brightness and this tone.

19. image processing method according to claim 18 also comprises the following step: (d) should adjust the back saturation and be converted to this two color elements C1 and C2.

20. image processing method according to claim 19 also comprises the following step: (e) this input picture is converted to this first color space by this second color space.

Images