CN101389040B

CN101389040B - Image sharpness adjustment method and device

Info

Publication number: CN101389040B
Application number: CN2007101521735A
Authority: CN
Inventors: 陈衣凡; 李维国
Original assignee: MStar Semiconductor Inc Taiwan
Current assignee: MediaTek Inc
Priority date: 2007-09-14
Filing date: 2007-09-14
Publication date: 2010-08-18
Anticipated expiration: 2027-09-14
Also published as: CN101389040A

Abstract

The invention discloses an image sharpness adjusting device, which comprises: a look-up table circuit for generating a set of color marks according to an input color signal; a color sharpness gain multiplexer coupled to the look-up table circuit for generating a set of first color sharpness gains according to the set of color marks and a plurality of color sharpness setting values, wherein each sharpness setting value is specific to a specific color; an interpolation circuit for performing interpolation operation according to the input color signal and the first color sharpness gain to generate a second color sharpness gain; and a brightness adjusting unit for adjusting a brightness signal according to the second color sharpness gain.

Description

Image sharpness regulating method and device

Technical field

The present invention relates to a kind of image sharpness control method and device, particularly relate to a kind of relevant for independent image sharpness control method and the device adjusting image sharpness and carry out with lookup table mode.

Background technology

For digital color image, judge the good and bad of digital color image quality usually, except depending on the color saturation of this digital color image, the color sharpness also is a very important index.

In the known technology, though have the method and the device of numerous adjustment image sharpness, in these methods and device, the user only can adjust its sharpness with regard to entire image, and these methods and device also can't allow the user adjust its sharpness at specific color.

So, the present invention proposes a kind of image sharpness regulating method and device, by the independent sharpness gain of adjusting single color in the coloured image, can independently adjust the sharpness of the different color of coloured image according to user's hobby, and then promote the quality of coloured image.

Summary of the invention

The object of the present invention is to provide a kind of image sharpness regulating method,, can independently adjust the sharpness of the different color of coloured image according to user's hobby by the independent sharpness gain of adjusting single color in the coloured image.

Another object of the present invention is to provide a kind of image sharpness adjusting device,, can independently adjust the sharpness of the different color of coloured image according to user's hobby by the independent sharpness gain of adjusting single color in the coloured image

To achieve these goals, the invention provides a kind of image sharpness regulating method, may further comprise the steps: receive an input chrominance signal; According to this input chrominance signal, tabling look-up determines one group of color indicia; According to this group color indicia and several sharpness set points, produce one group of first color sharpness gain, wherein each this sharpness set point is at a specific color; According to this first color sharpness gain and this input chrominance signal, produce the gain of one second color sharpness; And according to this second color sharpness gain adjustment, one luminance signal.

To achieve these goals, the present invention also provides a kind of image sharpness adjusting device, comprising: a lookup table circuit, in order to produce one group of color indicia according to an input chrominance signal; One color sharpness gain multiplexer is coupled to this lookup table circuit, in order to according to this group color indicia and several color sharpness set points, produces one group of first color sharpness gain, and wherein each this sharpness set point is at a specific color; One interpolating circuit in order to according to this input chrominance signal and this first color sharpness gain carrying out interpolative operation, gains to produce one second color sharpness; And a brightness adjustment unit, in order to adjust a luminance signal according to this second color sharpness gain.

From the above mentioned, image sharpness regulating method of the present invention and device allow the user can comply with its inclination, the independent sharpness of adjusting the different color of coloured image, and then the quality of lifting coloured image.

Describe the present invention below in conjunction with the drawings and specific embodiments, but not as a limitation of the invention.

Description of drawings

Fig. 1 is an image sharpness adjusting device of the present invention;

Fig. 2 is the brightness adjusting device of image sharpness adjusting device of the present invention;

Fig. 3 is an image sharpness regulating method flow chart of the present invention.

Wherein, Reference numeral:

100: the image sharpness adjusting device

110: lookup table circuit

120: color sharpness gain multiplexer

130: interpolating circuit

140: the brightness adjustment unit

210: edge detector

220: noise suppression circuit

Embodiment

Please refer to Fig. 1, Fig. 1 is the image sharpness adjusting device of preferred embodiment of the present invention.This image sharpness adjusting device 100 comprises a lookup table circuit 110, a color sharpness gain multiplexer 120, an interpolating circuit 130 and a brightness adjustment unit 140.Lookup table circuit 110 is in order to (Cb_in Cr_in) tables look-up and produces one group of color indicia (Flag1 ~ Flag4), this group color indicia is to form in order to the color of expression input chrominance signal according to an input chrominance signal.In actual applications, with eight chrominance signals is example, because the lookup table of corresponding eight chrominance signals needs bigger memory span, therefore the lookup table in the lookup table circuit 110 can design according to chrominance signal highest byte (MSB), for example, then, table look-up according to the highest byte (MSB) of this input chrominance signal again according to the preceding four highest bytes design of eight chrominance signals, saving the required memory span of lookup table circuit 110, and then reduce cost.

Color sharpness gain multiplexer 120 is coupled to lookup table circuit 110, in order to according to this group color indicia Flag1 ~ Flag4 and several color sharpness set points Set_R ~ Set_O, produces one group of first color sharpness gain Flag1_set ~ Flag4_set.Wherein R, G ..., O represent respectively red (red), green (green) ... and other color of wanting (other colors).Each color sharpness set point is at a specific color, and for example Set_R is the sharpness set point at redness, when the value that the user adjusts Set_R, is promptly adjusting red sharpness.

Interpolating circuit 130 is coupled to color sharpness gain multiplexer 120, organize first color sharpness gain Flag1_set ~ Flag4_set to receive this, and according to this input chrominance signal (Cb_in, Cr_in) lowest byte (LSB), interpolation produce one second color sharpness gain C_gain.In actual applications, if this chrominance signal is eight signals, and lookup table circuit 110 is according to four highest bytes design before the chrominance signal, and then interpolating circuit 130 utilizes four lowest bytes (LSB) of chrominance signal and this to organize the gain of the first color sharpness to carry out interpolation to produce the gain of the second color sharpness.In one embodiment, interpolating circuit 130 can be a bilinear interpolation arithmetic unit.

At last, brightness adjustment unit 140 is adjusted a luminance signal by this second color sharpness gain C_gain.Please refer to Fig. 2, it is for an embodiment schematic diagram of brightness adjustment unit 140.Brightness adjusting device 140 comprises an edge detector 210 and a noise suppression circuit 220.Edge detector 210 receives one brightness signal Y _ in, and gains C_gain to produce a luminance edges value Y_edge according to this second color sharpness.Noise suppression circuit 220 carries out noise suppressed to this brightness signal Y _ in and handles according to this a luminance edges value Y_edge and a critical value, to produce an output luminance signal.Detailed says, when this luminance edges value Y_edge is not more than this critical value, this output luminance signal is this brightness signal Y _ in, as this luminance edges value Y_edge during greater than this critical value, this output luminance signal is the difference that this brightness signal Y _ in adds this luminance edges value and this critical value.In one embodiment, this edge detector 210 comprises a high pass filter, and noise suppression circuit 220 comprises an adder.

Please refer to Fig. 3, Fig. 3 is the flow chart of the image sharpness regulating method of preferred embodiment of the present invention.At first, in step 301, receive an input chrominance signal.

Then, in step 302, by tabling look-up to determine the pairing one group of color indicia of this input chrominance signal.This group color indicia is to form in order to the color of expression input chrominance signal.In actual applications, the lookup table is according to chrominance signal highest byte (MSB) design, and for example preceding four highest bytes according to eight chrominance signals design, then, table look-up according to the highest byte (MSB) of this input chrominance signal again,, and then reduce cost with saving lookup table's memory span.

In step 303, according to this group color indicia and several sharpness set points, produce one group of first color sharpness gain, wherein each this sharpness set point allows the user carry out the setting of sharpness at different color at a specific color.

Then, in step 304, utilize four lowest bytes (LSB) of chrominance signal and this to organize the gain of the first color sharpness and carry out interpolation to produce the gain of the second color sharpness.

At last, in step 305, adjust a luminance signal according to this second color sharpness gain.Adjust in the luminance signal step at this, comprising:, produce a luminance edges value according to this luminance signal and the gain of this second color sharpness; Then,, this luminance signal is carried out noise suppressed handle, to produce an output luminance signal again according to this a luminance edges value and a critical value.Specifically, when this luminance edges value is not more than this critical value, this output luminance signal is this luminance signal, and when this luminance edges value during greater than this critical value, this output luminance signal is the difference that this luminance signal adds this luminance edges value and this critical value.

In sum, the present invention proposes a kind of image sharpness regulating method and device, allows the user can comply with its inclination, the independent sharpness of adjusting the different color of coloured image, and then the quality of lifting coloured image.

Certainly; the present invention also can have other various embodiments; under the situation that does not deviate from spirit of the present invention and essence thereof; those of ordinary skill in the art can make various corresponding changes and distortion according to the present invention, but these corresponding changes and distortion all should belong to the protection range of the appended claim of the present invention.

Claims

1. A method for adjusting image sharpness, comprising the following steps:

receiving an input color signal;

According to the input color signal, look up a table to determine a set of color marks;

generating a set of first color sharpness gains according to the set of color marks and several sharpness setting values, wherein each of the sharpness setting values is for a specific color;

generating a second color sharpness gain according to the first color sharpness gain and the input color signal; and

Receive an input luminance signal, generate a luminance edge value according to the luminance signal and the second color sharpness gain; perform noise suppression processing on the luminance signal according to the luminance edge value and a critical value, so as to generate an output luminance signal.

2. The image sharpness adjustment method according to claim 1, characterized in that, in the step of determining the group of color flags, a table lookup is performed according to the most significant byte of the input color signal.

3. The image sharpness adjustment method according to claim 2, wherein in the step of generating the second color sharpness gain, the second color sharpness gain is based on the lowest byte and The group of first color sharpness gains is generated by performing an interpolation operation.

4. The image sharpness adjustment method according to claim 3, wherein when the brightness edge value is not greater than the critical value, the output brightness signal is the brightness signal, and when the brightness edge value is greater than the critical value , the output luminance signal is the luminance signal plus the difference between the luminance edge value and the critical value.

5. A device for adjusting image sharpness, comprising:

A look-up table circuit for generating a group of color marks according to an input color signal;

A color sharpness gain multiplexer, coupled to the look-up circuit, is used to generate a set of first color sharpness gains according to the set of color marks and several color sharpness setting values, wherein each of the sharpness The setting value is for a specific color;

an interpolation circuit for performing an interpolation operation according to the input color signal and the first color sharpness gain to generate a second color sharpness gain; and

a brightness adjustment unit, used to receive an input brightness signal, generate a brightness edge value according to the brightness signal and the second color sharpness gain; perform noise suppression processing on the brightness signal according to the brightness edge value and a critical value, to generate an output luminance signal.

6. The image sharpness adjustment device according to claim 5, wherein the table look-up circuit uses the most significant byte of the input color signal to look up a table.

7. The image sharpness adjustment device according to claim 6, wherein the interpolation circuit uses the lowest byte of the input color signal to perform an interpolation operation.

8. The image sharpness adjustment device according to claim 5, wherein the brightness adjustment unit comprises:

an edge detector for generating a luminance edge value according to the luminance signal and the second color sharpness gain; and

A noise suppression circuit performs noise suppression processing on the brightness signal according to the brightness edge value and a critical value, so as to generate an output brightness signal.

9. The image sharpness adjustment device according to claim 8, wherein the edge detector comprises a high-pass filter.