CN101980521B - Image sharpening method and related device - Google Patents
Image sharpening method and related device Download PDFInfo
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Abstract
The embodiment of the invention discloses an image sharpening method and a related device for sharpening images in frequency bands so as to avoid sharpened image distortion. The method of the embodiment of the invention comprises the following steps of: acquiring luminance signals of input images; performing high-pass filtration on the luminance signals of the input images by using different frequency bands to obtain first high-frequency components corresponding to the frequency bands of current pixel points respectively; performing image analysis on the luminance signals of the input images to obtain edge information of the current pixel points and a luminance maximum and a luminance minimum in the luminance signals of the input images; determining gains corresponding to the first high-frequency components according to the luminance maximum, the luminance minimum and the edge information of the current pixel points; and sharpening the first high-frequency components according to the corresponding gains respectively, and outputting the processing results. The invention also provides the related device corresponding to the image sharpening method.
Description
Technical field
The present invention relates to image processing field, relate in particular to a kind of image sharpening method and relevant apparatus.
Background technology
A fuzzy image, in the epoch take " papery " as carrier, people have no way out to this " bluring ", but the arrival along with digital times, image can be transferred to computer and process, people have just had higher requirement to the definition of image, and with the fuzzy image clearly image processing process that becomes, are referred to as image sharpening.
Image blurring reason has a lot, such as: the shooting instrument is shaken when obtaining image, and the optical element of scanning device designs bad, or is subject to the interference etc. of noise in the process of image signal transmission.From the angle that image spectrum is analyzed, the fuzzy of image is that luminance difference is less between adjacent two pixels in the marginal portion of image, causes the sharpness of image inadequate because the high fdrequency component in the image is not enough.Process so we carry out sharpening to blurred picture, essence is exactly the high fdrequency component that reasonably improves in the image.
Traditional image sharpening method is the high fdrequency component in the simple enhancing image, so that the luminance difference of image border part improves, thereby reaches the effect of sharpening.But because most of noise all is image medium-high frequency component, if so simple enhancing high fdrequency component, sharpening when the edge, also can sharpening noise so that occur obvious irregular particle point in the image, had a strong impact on the quality of image; And because the luminance difference that each edge part branch shows in the image detail ought to be different, if unify the enhancing of amplification, meeting is so that the luminance difference that each details in the image shows becomes unreasonable, make sharpening after image fault larger.
In the prior art, before the high fdrequency component to image strengthens, can default one or several gain coefficient value come the high fdrequency component of image is strengthened, in the hope of distinguishing noise and edge feature, to a certain extent can noise reduction by the harmful effect of sharpening; But effect is often not ideal enough, the noise that still can appear at when carrying out edge sharpening also sharpening, and various edge details processes and still taked identical gain, and the luminance difference after the sharpening is reasonable not, and larger distortion appears in image after the sharpening.
Summary of the invention
The embodiment of the invention provides a kind of image sharpening method and relevant apparatus, and what be used for frequency-division section carries out sharpening to image, avoids the image fault after the sharpening.
Image sharpening method provided by the invention comprises: the luminance signal of obtaining input picture; Use respectively different frequency ranges that the luminance signal of input picture is carried out high-pass filtering and process, obtain the first high fdrequency component corresponding to each frequency range of current pixel point; Luminance signal to input picture is carried out graphical analysis, obtains the marginal information of described current pixel point, the brightness maximum in the luminance signal of input picture and brightness minimum value; According to described brightness maximum, the marginal information of brightness minimum value and current pixel point is determined gain corresponding to described the first high fdrequency component; Gain according to described correspondence is carried out sharpening to described the first high fdrequency component respectively, and the output result.
Image sharpening device provided by the invention comprises: the first acquiring unit, and for the luminance signal of obtaining input picture, described input picture is comprised of the pixel in current pixel point and the current pixel neighborhood of a point; High pass filter unit is used for using respectively different frequency ranges that the luminance signal of input picture is carried out high-pass filtering and processes, and obtains current pixel point first high fdrequency component corresponding with each frequency range; Image analyzing unit is used for the luminance signal of input picture is carried out graphical analysis, obtains the marginal information of described current pixel point, the brightness maximum in the luminance signal of input picture and brightness minimum value; Gain control unit is used for according to described brightness maximum, and the marginal information of brightness minimum value and current pixel point is determined gain corresponding to described the first high fdrequency component; Output control unit is used for respectively described the first high fdrequency component being carried out sharpening according to the gain of described correspondence, and the output result.
As can be seen from the above technical solutions, the embodiment of the invention has the following advantages: the present invention is after getting access to the luminance signal of input picture, using different frequency ranges that this luminance signal is carried out respectively high-pass filtering processes, obtain first high fdrequency component corresponding with each frequency range, then this luminance signal is carried out graphical analysis, obtain the corresponding gain of each frequency range high fdrequency component, gain according to this correspondence is carried out sharpening to the high fdrequency component of each frequency range respectively, thereby reaches the purpose of reasonably sharpening being carried out in the image border.
Description of drawings
Fig. 1 is a schematic flow sheet of embodiment of the invention image sharpening method;
Fig. 2 is another schematic flow sheet of embodiment of the invention image sharpening method;
Fig. 3 is the illustration that carries out 4 direction edge filters in the embodiment of the invention image sharpening method;
Fig. 4 is another schematic flow sheet of embodiment of the invention image sharpening method;
Fig. 5 is a logical construction schematic diagram of embodiment of the invention image sharpening method;
Fig. 6 is the principle schematic of multi-band high pass filter in the embodiment of the invention image sharpening method;
Fig. 7 is the illustration of sectional-continuous function in the embodiment of the invention image sharpening method.
Embodiment
The embodiment of the invention provides a kind of image sharpening method and relevant apparatus, and what be used for frequency-division section carries out sharpening to image, avoids the image fault after the sharpening.
See also Fig. 1, image sharpening method embodiment comprises in the embodiment of the invention:
101, obtain luminance signal;
Image sharpening device scans present image, obtains the luminance signal of input picture.
This input picture can be the matrix video in window that gets access to centered by current pixel point, is comprised of current pixel point and neighborhood territory pixel point thereof, and image sharpening device need to be analyzed by the neighborhood territory pixel point of current pixel point the processing of current pixel point.
This luminance signal can be the signal of the Y representative in the YUV model, or the signal of the V representative in the HSV model, or the signal of the I representative in the HIS model, or the luminance signal in other the data model.
102, the high-pass filtering of frequency-division section;
Image sharpening device uses respectively different frequency ranges that the luminance signal of input picture is carried out high-pass filtering and processes, and obtains the first high fdrequency component corresponding to each frequency range of current pixel point.
The sharpening of image is in fact the sharpening to the margin signal in the image, thereby reaches the effect that improves image definition.And the margin signal of input picture generally all is high-frequency signal, the luminance signal of input picture is carried out the high-pass filtering of different frequency range and processes, and can filter out the low frequency signal in the input picture, obtains the high fdrequency component of the margin signal of corresponding each frequency range.
It then is for edge details different in the differentiate between images that frequency-division section carries out the high-pass filtering processing to luminance signal, and different edge details is processed respectively.The high-pass filtering that the present invention can use the multi-band high pass filter to carry out multiband is processed, and for example: minute three frequency ranges are carried out high-pass filtering, the division of the frequency band of multi-band high pass filter as shown in Figure 6, wherein, A1, A2 and A3 represent respectively three frequency ranges.The bandwidth of A1 is the narrowest, only allows in the luminance signal part of high frequency to pass through, and it is wider that the bandwidth ratio A1 of A2 wants, and the bandwidth of A3 frequency range is the widest.
103, graphical analysis;
Image sharpening device carries out graphical analysis to this luminance signal, and graphical analysis can be divided into two parts: rim detection and signal characteristic abstraction.
After step 102 pair this luminance signal is carried out the high-pass filtering processing, obtain the radio-frequency component in the luminance signal, but because noise also has the feature of high frequency, when the high-pass filtering of carrying out different frequency range is processed, probably there is the frequency of one or several frequency range to overlap with the frequency of noise, so may there be noise signal to be mixed in the inside in the high fdrequency component that obtains, then need to carry out rim detection this moment, to distinguish margin signal and noise signal.After distinguishing margin signal, the marginal information of output current pixel point is that the signal of marginal point carries out sharpening to current pixel point only.
In the luminance signal of this input picture, comprised the feature of various luminance signals, such as the brightness of each pixel in the input picture; The image sharpening device of the embodiment of the invention can obtain brightness maximum and the brightness minimum value in the neighborhood territory pixel point of current pixel point, as the reference data of determining the gain of the first high fdrequency component.
Be understandable that in practical operation, image sharpening device can also extract more signal characteristics according to the needs of gain accuracy in luminance signal, participate in the calculating of gain, specifically is not construed as limiting herein.
104, determine corresponding gain;
Image sharpening device is according to the marginal information of current pixel point, and the minimum value of the maximum of brightness in the luminance signal of neighborhood and brightness is determined the corresponding gain of each frequency range the first high fdrequency component.
In image sharpening of the present invention, yield value corresponding to different frequency range meeting, the effect of processing respectively with the details that reaches edge then can be adjusted the size of yield value according to brightness maximum and brightness minimum value, so that the sharpening at edge is more reasonable.Specifically how to adjust and in follow-up embodiment, to be described according to brightness maximum and brightness minimum value.
After image sharpening device carried out rim detection, image sharpening device was only to carrying out sharpening for the marginal point signal.
105, output result.
Image sharpening device carries out sharpening to the first high fdrequency component of each frequency range respectively according to the gain of correspondence, and the output result.
After the first high fdrequency component of each frequency range is carried out sharpening, can carry out suitable control to Output rusults according to the result after the sharpening, to reach the more rational effect that image is processed, concrete control method can be described in follow-up embodiment.
The embodiment of the invention is after getting access to the luminance signal of input picture, using different frequency ranges that this luminance signal is carried out respectively high-pass filtering processes, obtain first high fdrequency component corresponding with each frequency range, then this luminance signal is carried out graphical analysis, obtain the corresponding gain of each frequency range high fdrequency component, gain according to this correspondence is carried out sharpening to the high fdrequency component of each frequency range respectively, thereby reaches the purpose of reasonably sharpening being carried out in the image border.
The effect of rim detection directly has influence on the effect of image sharpening, and the invention process provides a kind of method of rim detection of effective eliminating noise, specifically sees also Fig. 2, and another embodiment of image processing method comprises in the embodiment of the invention:
201～202, step 101 and 102 content are identical among the step 201 in the present embodiment and 202 content and the aforementioned embodiment shown in Figure 1, repeat no more herein.
203, obtain the image brightness matrix;
Image sharpening device obtains the luminance matrix of this input picture, this luminance matrix is comprised of the brightness value of current pixel point and the brightness value of neighborhood territory pixel point thereof, this luminance matrix is that M and N are N * Metzler matrix greater than 2 length and width all, and current pixel point is positioned at the center of this matrix.
204, edge filter;
Image sharpening device carries out respectively the edge filter of K direction to this matrix.Generally speaking, can select K is 4, namely this matrix is carried out horizontal direction, vertical direction, the edge filter of 45 degree and 135 degree.For the image of some more complicated, also can adopt the edge filter more than 4 directions.
Be understandable that K direction is not limited to 4 above-mentioned directions, choosing of K value can decide according to the requirement of precision that filter is made an uproar and the performance for the treatment of facility, do not do concrete restriction herein.
Image sharpening device is set the direction matrix of K direction, direction matrix also be that M and N are N * Metzler matrix greater than 2 length and width all.
Take the direction matrix of 5 * 3 matrixes on 4 directions as example, see also Fig. 3, E2, E0, E1, E3 respectively are vertically, level, 45 is spent, 135 direction matrixes of spending on 4 directions, and the numerical value in the matrix represents the slope of pixel on this matrix directions of this correspondence position.
205, calculated direction coefficient;
Image sharpening device is determined current pixel point corresponding K direction coefficient on K direction according to K direction matrix and luminance matrix.
The concrete computational methods of direction coefficient can for: the point of correspondence position in the point in the direction matrix and the luminance matrix is multiplied each other, and takes absolute value after the value addition of the N * M that will obtain after will multiplying each other point, obtain the make progress direction coefficient of current pixel point of the party.
The computational methods of above-mentioned direction coefficient have only listed a kind of, are understandable that, direction coefficient can also have other computational methods in actual applications, specifically is not construed as limiting herein.
206, determine the edge direction coefficient;
Image sharpening device is the size of this K direction coefficient relatively, and the direction coefficient that value is maximum is as the edge direction coefficient, and maximum direction corresponding to direction coefficient is edge direction.
207, initialization edge counter;
Image sharpening device compares the size of edge direction coefficient and Second Threshold, if the edge direction coefficient, determines tentatively then that this current pixel point is the marginal point on the edge direction coefficient correspondence direction more than or equal to Second Threshold, the edge counter is initialized as 1.
If the edge direction coefficient, determines then that current pixel point is not marginal point less than Second Threshold, the edge counter is initialized as 0.
Second Threshold is default parameter value, if the computational methods of direction coefficient are different, this Second Threshold is also different.If the edge direction coefficient, thinks then that current pixel point has edge feature at this edge direction coefficient correspondence direction more than or equal to Second Threshold, determine that simultaneously the direction of current pixel point is direction corresponding to edge direction coefficient.
208, judge image complexity;
After definite current pixel point has edge feature, can be according to the requirement of precision that filter is made an uproar, determine whether continue to distinguish whether current pixel point is marginal point, because use the settled preceding pixel point of above-mentioned method to have after the edge feature, current pixel point still might be noise spot, if so to the filter higher image of required precision (complexity such as image is higher) of making an uproar, need then further to distinguish whether current pixel point is marginal point.
Image sharpening device judges whether further to carry out rim detection according to the complexity of input picture, concrete step can for:
The average brightness of having a few in the brightness value of each point in the N of current point * M neighborhood and this neighborhood is subtracted each other, and the rear summation that again each difference taken absolute value obtains the complexity metric value, the size of more complicated degree metric and complexity threshold;
If the complexity metric value, thinks then that this input picture is simple less than complexity threshold, have edge feature (the edge counter is initialized as 1) afterwards in definite current pixel point, just trigger step 211.
If the complexity metric value, thinks then that this input picture is complicated more than or equal to complexity threshold, determine that current pixel point has edge feature (the edge counter is initialized as 1) afterwards, trigger step 209, carry out further rim detection.
The method of above-mentioned judgement complexity only for the embodiment of the invention enumerate a kind of, be understandable that in actual applications, the present invention can also use other to judge the method (such as variance) of image complexities, specifically is not construed as limiting herein.
209, obtain edge direction;
Image sharpening device obtain current pixel point with and the edge direction of neighbor pixel.
Neighbor pixel is chosen in 8 pixels adjacent with current pixel point, generally chooses the left side of current pixel point, and is upper left, top and 4 upper right neighbor pixels, and direction is respectively level, 135 degree, vertical and 45 degree.
Determine neighborhood territory pixel point edge direction method can for: if the edge direction coefficient of neighborhood territory pixel point is more than or equal to Second Threshold, and edge direction corresponding to the edge direction coefficient of this neighborhood territory pixel point is the edge direction of neighborhood territory pixel point, and triggers step 210; If the edge direction coefficient of neighborhood territory pixel point is less than Second Threshold, then the neighborhood territory pixel point does not have direction, needn't trigger step 210, and the counting of this neighborhood territory pixel point finishes.
210, relatively direction is poor;
Image sharpening device relatively current pixel point with edge direction neighborhood territory pixel point, be less than or equal to presetting angle if the edge direction of current pixel point and one of them neighborhood territory pixel point differs, then the edge counter adds 1.
Image sharpening device is determined the yield value size according to the value of edge counter in follow-up step, for example: if the value of edge counter, thinks then that current pixel point is not marginal point less than the 3rd threshold value, gain corresponding to each the first high fdrequency component all is set to zero.If the value of edge counter, thinks then that current pixel point is marginal point more than or equal to the 3rd threshold value, gain corresponding to each the first high fdrequency component should not be set to zero.If the 3rd threshold value is set to 2, then image sharpening device thinks that current pixel point links to each other with an adjacent neighborhood territory pixel point at least, determines that just current pixel point is marginal point.
When edge direction is elected the four direction of describing in the step 209 as, this presetting angle is traditionally arranged to be 45 degree, if be less than or equal to 45 degree so the direction of the direction of current pixel point and neighborhood territory pixel point differs, think that then current pixel point and this neighborhood territory pixel point are continuous, the edge counter will add 1.
211, output marginal information;
The size of the value of the image analyzing unit output edge counter in the image sharpening device is so that the gain control unit in the image sharpening device can be determined the gain that each the first high fdrequency component is corresponding according to the value of edge counter.
212, signal characteristic abstraction;
Image sharpening device carries out graphical analysis to luminance signal, extracts the feature of this luminance signal, comprises that brightness changes speed tolerance, brightness maximum and brightness minimum value in the N of current pixel point * M neighborhood, is used for determining gain corresponding to each the first high fdrequency component.This brightness changes speed tolerance and is the amplitude peak of brightness variation (being the absolute value of difference) between all two adjacent brightness values in the N of current pixel point * M neighborhood.Two adjacent pixels can be adjacent on level or vertical direction, also can to the angular direction or more multi-direction adjacent, specifically be not construed as limiting herein.
Be understandable that in practical operation, image sharpening device can also extract more signal characteristics according to the needs of gain accuracy in luminance signal, participate in the calculating of gain, specifically is not construed as limiting herein.
213, determine yield value;
Image sharpening device is according to the value of edge counter corresponding to current pixel point, and brightness variation speed tolerance, brightness maximum and brightness minimum value are determined the corresponding gain of each frequency range the first high fdrequency component in the luminance signal.
214, output result.
Image sharpening device carries out sharpening to the first high fdrequency component of each frequency range respectively according to the gain of correspondence, and the output result.
In the embodiment of the invention, before carrying out image sharpening, a kind of effective edge detection method is provided, this edge detection method can be according to the precision of the image local complexity being adjusted rim detection, so that image sharpening device is more flexible and accurate to the control of noise, also improved the quality of image sharpening simultaneously.
Image sharpening device directly affects the expression effect of image detail after the sharpening on the control of the corresponding gain of each frequency range, the embodiment of the invention provides a kind of sectional-continuous function, accurately control has been carried out in corresponding gain to each frequency range, see also Fig. 4, another embodiment of image processing method comprises in the embodiment of the invention:
401～402, step 101 and 102 content are identical among the step 401 in the present embodiment and 402 content and the aforementioned embodiment shown in Figure 1, repeat no more herein.
403, rim detection;
Image sharpening device carries out rim detection to input picture, the value of the edge counter that the output current pixel point is corresponding.Concrete edge detection method can be consulted among Fig. 2 embodiment step 203 also can use other edge detection method to the edge detection method shown in 211, specifically is not construed as limiting herein.
404, signal characteristic abstraction;
Image sharpening device carries out the luminance signal feature extraction to input picture, obtain brightness variation speed tolerance maxstep, brightness maximum and brightness minimum value in the current pixel neighborhood of a point, be used for to determine gain corresponding to each the first high fdrequency component, and to the control of processing result image output.
Be understandable that in practical operation, image sharpening device can also extract more signal characteristics according to the needs of gain accuracy in luminance signal, participate in the calculating of gain, specifically is not construed as limiting herein.
405, obtain the brightness excursion;
Brightness maximum and brightness minimum value that image sharpening device obtains after with signal characteristic abstraction are subtracted each other, and obtain brightness excursion Range.
406, determine yield value by judging;
Image sharpening device is set up a sectional-continuous function, according to brightness excursion Range, correspond in this sectional-continuous function certain a bit, in order to determine the gain of current pixel point in each frequency range.
The segmentation of this function be by two groups or more the parameter of multiple preset determine.Because brightness excursion Range has reflected near the details the current pixel point, different brightness excursions needs the enhancing of corresponding different amplitudes, just can reach the effect of image being carried out reasonable sharpening.And use the purpose of continuous function to be: so that object edge brightness hypermetamorphosis is natural continuously, can not produce the ill effect that jumping characteristic brightness strengthens.
Below take three sections LINEAR CONTINUOUS functions as example, determine the yield value that each frequency range is corresponding, see also Fig. 7:
Image sharpening device is the value and the size of the 3rd threshold value of edge counter at first relatively, if the value of edge counter less than the 3rd threshold value, then gain corresponding to all the first high fdrequency components is zero; If the value of edge counter more than or equal to the 3rd threshold value, then continues to carry out following steps.
Image sharpening device compares brightness excursion Range, the first preset parameter HEIGHT_THD1 and the second preset parameter HEIGHT_THD0;
If the brightness excursion is more than or equal to the first preset parameter HEIGHT_THD1, then the gain G ainx of x frequency range equals the first preset gain Bx_GAIN1 corresponding to x frequency range;
If the brightness excursion is less than the second preset parameter HEIGHT_THD0, then calculate the gain of x frequency range according to Gainx=Bx_GAIN0*Range/HEIGHT_THD0, this Bx_GAIN0 is the second preset gain corresponding to x frequency range, and this first preset parameter HEIGHT_THD1 is greater than the second preset parameter HEIGHT_THD0;
If the brightness excursion more than or equal to the second preset parameter and less than the first preset parameter, is then calculated the gain of x frequency range according to Gainx=Bx_GAIN0+ (Bx_GAIN-1-Bx_GAIN0) * (Range-HEIGHT_THD0)/(HEIGHT_THD1-HEIGHT_THD0).
407, adjust corresponding gain;
Image sharpening device is after obtaining gain corresponding to each the first high fdrequency component, if Range equals zero, then establishing Modulation is zero; If Range is greater than zero, then calculate the adjusted value Modulation of gain according to Modulation=(MODULATION_K*maxstep)/Range, maxstep is that the brightness that obtains in step 404 graphical analysis changes speed tolerance, and MODULATION_K is the gain adjustment value of system intialization.
Image sharpening device is adjusted output gain according to the adjusted value Modulation of gain, specifically can according to formula: Gainx=(256-Modulation) * Gainx/256, adjust.
Output gain is adjusted, can so that originally clearly edge (being that adjacent point-to-point transmission luminance difference is larger) use less yield value to carry out sharpening, originally fuzzy edge (being that adjacent point-to-point transmission luminance difference is less) uses larger yield value to carry out sharpening, thereby reaches the effect of image being carried out reasonable sharpening.
408, definite and output sharpened value;
Gain after image sharpening device will be adjusted is multiplied each other with the first high fdrequency component of corresponding each frequency range respectively, obtains the second high fdrequency component after each frequency range sharpening.With each the second high fdrequency component addition, obtain the brightness changing value of current pixel point; With the added luminance of brightness changing value and current pixel point, obtain the sharpened value of current pixel point.
Image sharpening device is this sharpened value, brightness minimum value and the peaked size of brightness relatively;
If this sharpened value is more than or equal to the brightness minimum value, and be less than or equal to the brightness maximum, then this sharpened value is constant;
If this sharpened value is greater than the brightness maximum, then this sharpened value is adjusted into the brightness maximum;
If this sharpened value is less than the brightness minimum value, then this sharpened value is adjusted into the brightness minimum value.
Sharpened value after adjusting and the brightness value of current pixel point are subtracted each other the brightness changing value after being adjusted.
Brightness changing value after relatively adjusting and the size of first threshold are if the absolute value of the brightness changing value after adjusting then uses the brightness value of current pixel point to upgrade this sharpened value less than first threshold;
If the absolute value of the brightness changing value after adjusting is more than or equal to first threshold, then when this brightness changing value be on the occasion of the time, the difference renewal brightness changing value that uses brightness changing value after adjusting and first threshold to subtract each other; When this brightness changing value is negative value, the brightness changing value after use adjusting and first threshold addition with renewal brightness changing value; Brightness changing value after use upgrading and current pixel point brightness value with this sharpened value of renewal.
The noise of image can be presented as less value usually on the brightness changing value; the embodiment of the invention avoids adding very noisy as much as possible, so be provided with first threshold, if the brightness changing value is less than first threshold; think that then this brightness variation belongs to this special image expression effect, does not strengthen.
Result by behind the above-mentioned judgement control image sharpening can so that image strengthens, reduce distortion as much as possible between original luminance difference.
Provide a kind of in the embodiment of the invention and calculated respectively the method for the corresponding gain of each frequency range according to sectional-continuous function, so that image sharpening device processes respectively the different details in the image, thereby reached the effect of reasonably carrying out image sharpening; Also the view data after the sharpening is controlled in the embodiment of the invention, kept as much as possible original effect of image, reduced image fault.
The below describes the embodiment for the image sharpening device of the present invention of carrying out above-mentioned image sharpening method, and its logical construction please refer to Fig. 5, and embodiment of the image sharpening device in the embodiment of the invention comprises:
The first acquiring unit 501, for the luminance signal of obtaining input picture, this input picture is comprised of the neighborhood territory pixel point of current pixel point and current pixel point;
High pass filter unit 502 is used for using respectively different frequency ranges that the luminance signal of input picture is carried out high-pass filtering and processes, and obtains the first high fdrequency component corresponding to each frequency range of current pixel point;
The output control unit of the image sharpening device in the embodiment of the invention can further include:
Sharpening unit 5051 is used for each gain is multiplied each other with corresponding the first high fdrequency component respectively, obtains the second high fdrequency component after each frequency range sharpening; With each the second high fdrequency component addition, obtain the brightness changing value of current pixel point; With the added luminance of this brightness changing value and current pixel point, obtain the sharpened value of current pixel point;
The first control unit 5052 if be used for this sharpened value more than or equal to this brightness minimum value, and is less than or equal to this brightness maximum, and then this sharpened value is constant;
The second control unit 5053, if be used for this sharpened value greater than this brightness maximum, then this sharpened value is adjusted into this brightness maximum;
The 3rd control unit 5054, if be used for this sharpened value less than this brightness minimum value, then this sharpened value is adjusted into this brightness minimum value.
Sharpened value adjustment unit 5055, the sharpened value after being used for adjusting and the brightness value of current pixel point subtract each other the brightness changing value after being adjusted; If the absolute value of the brightness changing value after adjusting then uses the brightness value of current pixel point to upgrade this sharpened value less than first threshold; If the absolute value of the brightness changing value after adjusting is more than or equal to first threshold, then when this brightness changing value be on the occasion of the time, the difference renewal brightness changing value that uses brightness changing value after adjusting and first threshold to subtract each other; When this brightness changing value is negative value, the brightness changing value after use adjusting and first threshold addition with renewal brightness changing value; Brightness changing value after use upgrading and current pixel point brightness value with this sharpened value of renewal.
The image analyzing unit of the image sharpening device in the embodiment of the invention can further include:
Edge filter unit 5032 for the edge filter that this luminance matrix is carried out respectively K direction, obtains K direction coefficient of current pixel point correspondence on K direction;
Comparing unit 5033 is used for the relatively size of K direction coefficient, and the direction coefficient that value is maximum is as the edge direction coefficient;
Edge counting initialization unit 5034 is used for whether judging the edge direction coefficient more than or equal to Second Threshold that if not, then the value initialization with the edge counter is 0; If then the value initialization with the edge counter is 1;
Marginal information output unit 5035, the value of output edge counter;
Signal characteristic acquiring unit 5036 is for brightness maximum and the brightness minimum value of the luminance signal of obtaining input picture;
Signal characteristic output unit 5037 is for brightness maximum and the brightness minimum value of output brightness signal.
The concrete reciprocal process of the unit of embodiment of the invention image processing apparatus is as follows:
The first acquiring unit 501 obtains the luminance signal of input picture, and this input picture is comprised of the neighborhood territory pixel point of current pixel point and current pixel point; High pass filter unit 502 is used respectively different frequency ranges that the luminance signal of input picture is carried out high-pass filtering and is processed, and obtains the first high fdrequency component corresponding to each frequency range of current pixel point; Simultaneously, the luminance signal of 503 pairs of input pictures that get access to of image analyzing unit is carried out graphical analysis.
Graphical analysis can be divided into two parts: rim detection and signal characteristic abstraction.The rim detection detailed process is: second acquisition unit 5031 obtains the luminance matrix of input picture, and this luminance matrix is comprised of the brightness value of current pixel point and the brightness value of neighborhood territory pixel point, and luminance matrix is the matrix of N * M, and M and N are greater than 2; 5032 pairs of these luminance matrix in edge filter unit carry out respectively the edge filter of K direction, obtain K direction coefficient of current pixel point correspondence on K direction; Comparing unit 5033 is the size of K direction coefficient relatively, and the direction coefficient that value is maximum is as the edge direction coefficient; Edge counting initialization unit 5034 is used for whether judging the edge direction coefficient more than or equal to Second Threshold that if not, then the value initialization with the edge counter is 0; If then the value initialization with the edge counter is 1; Marginal information output unit 5035, the value of output edge counter.
The signal characteristic abstraction detailed process is: signal characteristic acquiring unit 5036, for brightness maximum and the brightness minimum value of the luminance signal of obtaining input picture; Signal characteristic output unit 5037 is for brightness maximum and the brightness minimum value of output brightness signal.
Marginal information, brightness maximum and the brightness minimum value of each first high fdrequency component that gain control unit 504 obtains in conjunction with high pass filter unit 502 and image analyzing unit 503 outputs are determined the gain that the first high fdrequency component is corresponding.
The process of output control is specially: sharpening unit 5051 multiplies each other each gain respectively with corresponding the first high fdrequency component, obtains the second high fdrequency component after each frequency range sharpening; With each the second high fdrequency component addition, obtain the brightness changing value of current pixel point; With the added luminance of this brightness changing value and current pixel point, obtain the sharpened value of current pixel point; If this sharpened value is more than or equal to this brightness minimum value, and be less than or equal to this brightness maximum, 5052 of the first control units keep this sharpened value constant; If this sharpened value is greater than this brightness maximum, 5053 of the second control units are adjusted into this brightness maximum with this sharpened value; If this sharpened value is less than this brightness minimum value, 5054 of the 3rd control units are adjusted into this brightness minimum value with this sharpened value.
After sharpened value adjusted, sharpened value adjustment unit 5055 used the sharpened value after adjusting to deduct the brightness value of current pixel point, the brightness changing value after being adjusted.If the absolute value of the brightness changing value after adjusting then uses the brightness value of current pixel point to upgrade this sharpened value less than first threshold; If the absolute value of the brightness changing value after adjusting is more than or equal to first threshold, then when this brightness changing value be on the occasion of the time, the difference renewal brightness changing value that uses brightness changing value after adjusting and first threshold to subtract each other; When this brightness changing value is negative value, the brightness changing value after use adjusting and first threshold addition with renewal brightness changing value; Brightness changing value after use upgrading and current pixel point brightness value with this sharpened value of renewal.
One of ordinary skill in the art will appreciate that all or part of step that realizes in above-described embodiment method is to come the relevant hardware of instruction to finish by program, described program can be stored in a kind of computer-readable recording medium, the above-mentioned storage medium of mentioning can be read-only memory, disk or CD etc.
More than a kind of image sharpening method provided by the present invention and relevant apparatus are described in detail, for one of ordinary skill in the art, thought according to the embodiment of the invention, all will change in specific embodiments and applications, in sum, this description should not be construed as limitation of the present invention.
Claims (12)
1. an image sharpening method is characterized in that, comprising:
Obtain the luminance signal of input picture, described input picture is comprised of the pixel in current pixel point and the current pixel neighborhood of a point;
Use respectively different frequency ranges that the luminance signal of input picture is carried out high-pass filtering and process, obtain current pixel point first high fdrequency component corresponding with each frequency range;
Luminance signal to input picture is carried out graphical analysis, obtains the marginal information of described current pixel point, the brightness maximum in the luminance signal of input picture and brightness minimum value;
According to described brightness maximum, the marginal information of brightness minimum value and current pixel point is determined gain corresponding to described the first high fdrequency component;
Described gain is multiplied each other with corresponding the first high fdrequency component respectively, obtain the second high fdrequency component after each frequency range sharpening; With each the second high fdrequency component addition, obtain the brightness changing value of current pixel point; With the added luminance of described brightness changing value and current pixel point, obtain the sharpened value of current pixel point;
If described sharpened value is more than or equal to described brightness minimum value, and be less than or equal to described brightness maximum, then described sharpened value is constant;
If described sharpened value is greater than the brightness maximum, then described sharpened value is adjusted into described brightness maximum;
If described sharpened value is less than the brightness minimum value, then described sharpened value is adjusted into described brightness minimum value.
2. method according to claim 1 is characterized in that, comprises after the described adjustment sharpened value:
Sharpened value after adjusting and the brightness value of current pixel point are subtracted each other the brightness changing value after being adjusted;
If the absolute value of the brightness changing value after adjusting then uses the brightness value of current pixel point to upgrade described sharpened value less than first threshold;
If the absolute value of the brightness changing value after adjusting is more than or equal to first threshold, then when described brightness changing value be on the occasion of the time, the difference renewal brightness changing value that uses brightness changing value after adjusting and first threshold to subtract each other; When described brightness changing value is negative value, the brightness changing value after use adjusting and first threshold addition with renewal brightness changing value; Brightness changing value after use upgrading and current pixel point brightness value with the described sharpened value of renewal.
3. method according to claim 1 is characterized in that, described luminance signal to input picture is carried out graphical analysis, and the marginal information that obtains described current pixel point comprises:
Obtain the luminance matrix of described input picture, described luminance matrix is comprised of the brightness value of described current pixel point and the brightness value of neighborhood territory pixel point, and described luminance matrix is the matrix of N * M, and described M and N are greater than 2;
Described luminance matrix is carried out respectively the edge filter of K direction, obtain described current pixel point corresponding K direction coefficient on K direction;
The size of a more described K direction coefficient, the direction coefficient that value is maximum is as the edge direction coefficient;
Whether judge the edge direction coefficient more than or equal to Second Threshold, if not, then the value initialization with the edge counter is 0; If then the value initialization with the edge counter is 1;
The value of output edge counter.
4. method according to claim 3 is characterized in that, described luminance matrix is carried out respectively the edge filter of K direction, obtains described current pixel point K corresponding direction coefficient on K direction and comprises:
1) default K direction matrix, described K is more than or equal to 1, and described direction matrix is the matrix of N * M;
2) point with correspondence position in the point in the square upward direction matrix and the described luminance matrix multiplies each other, and with taking absolute value after N * M the value addition of putting that obtains, obtains the direction coefficient of current pixel point on the described direction;
3) according to step 2) described method, obtain respectively K K the direction coefficient that direction is corresponding.
5. method according to claim 3 is characterized in that, described value initialization with the edge counter comprises after 1:
Obtain the edge direction of described current pixel point and current pixel point neighbor pixel;
Be less than or equal to presetting angle if the edge direction of the edge direction of current pixel point and a neighborhood territory pixel point differs, then the value of edge counter adds 1.
6. according to claim 1 to the described method of 5 any one, it is characterized in that described according to described brightness maximum, the marginal information of brightness minimum value and current pixel point determines that gain corresponding to described the first high fdrequency component comprises:
If the value of edge counter is less than the 3rd threshold value, then gain corresponding to all frequency ranges is zero;
If the value of edge counter more than or equal to the 3rd threshold value, is then subtracted each other described brightness maximum and brightness minimum value, obtain brightness excursion Range;
If described brightness excursion is more than or equal to the first preset parameter HEIGHT_THD1, then gain G ainx equals the first preset gain Bx_GAIN1 corresponding to x frequency range;
If described brightness excursion is less than or equal to the second preset parameter HEIGHT_THD0, then according to the Gainx=Bx_GAIN0*Range/HEIGHT_THD0 calculated gains, described Bx_GAIN0 is the second preset gain corresponding to x frequency range, and described the first preset parameter is greater than the second preset parameter;
If described brightness excursion is greater than the second preset parameter and less than the first preset parameter, then according to Gainx=Bx_GAIN0+ (Bx_GAIN1-Bx_GAIN0) * (Range-HEIGHT_THD0)/(HEIGHT_THD1-HEIGHT_THD0) calculated gains;
Export the gain corresponding with described each the first high fdrequency component.
7. method according to claim 6 is characterized in that, the described output gain corresponding with described each the first high fdrequency component comprises afterwards:
Luminance signal to input picture is carried out graphical analysis, obtain brightness variation speed tolerance maxstep in the described luminance signal, described brightness changes speed tolerance and is the maximum of the absolute value of the difference of the brightness value of adjacent two pixels in the described neighborhood of input picture;
If Range equals zero, then Modulation is made as zero;
If Range greater than zero, then calculates the adjusted value Modulation of described gain according to Modulation=(MODULATION_K*maxstep)/Range; Described MODULATION_K is the preset gain adjusted value;
Adjusted value according to described gain is adjusted gain corresponding to described each the first high fdrequency component.
8. method according to claim 7 is characterized in that, described adjusted value according to gain is adjusted gain corresponding to each frequency range of described current pixel point and comprised:
Adjust the size of gain corresponding to described each the first high fdrequency component according to formula Gainx=(256-Modulation) * Gainx/256.
9. an image sharpening device is characterized in that, comprising:
The first acquiring unit, for the luminance signal of obtaining input picture, described input picture is comprised of the pixel in current pixel point and the current pixel neighborhood of a point;
High pass filter unit is used for using respectively different frequency ranges that the luminance signal of input picture is carried out high-pass filtering and processes, and obtains current pixel point first high fdrequency component corresponding with each frequency range;
Image analyzing unit is used for the luminance signal of input picture is carried out graphical analysis, obtains the marginal information of described current pixel point, the brightness maximum in the luminance signal of input picture and brightness minimum value;
Gain control unit is used for according to described brightness maximum, and the marginal information of brightness minimum value and current pixel point is determined gain corresponding to described the first high fdrequency component;
Output control unit is used for respectively described the first high fdrequency component being carried out sharpening according to the gain of described correspondence, and the output result; Described output control unit comprises: sharpening unit, the first control unit, the second control unit and the 3rd control unit;
The sharpening unit is used for described gain is multiplied each other with corresponding the first high fdrequency component respectively, obtains the second high fdrequency component after each frequency range sharpening; With each the second high fdrequency component addition, obtain the brightness changing value of current pixel point; With the added luminance of described brightness changing value and current pixel point, obtain the sharpened value of current pixel point;
The first control unit if be used for described sharpened value more than or equal to described brightness minimum value, and is less than or equal to described brightness maximum, then keeps described sharpened value constant;
The second control unit, if be used for described sharpened value greater than described brightness maximum, then described sharpened value is adjusted into described brightness maximum;
The 3rd control unit, if be used for described sharpened value less than described brightness minimum value, then described sharpened value is adjusted into described brightness minimum value.
10. described device according to claim 9 is characterized in that described output control unit also comprises:
The sharpened value adjustment unit, the sharpened value after being used for adjusting and the brightness value of current pixel point subtract each other the brightness changing value after being adjusted; If the absolute value of the brightness changing value after adjusting then uses the brightness value of current pixel point to upgrade described sharpened value less than first threshold; If the absolute value of the brightness changing value after adjusting is more than or equal to first threshold, then when described brightness changing value be on the occasion of the time, the difference renewal brightness changing value that uses brightness changing value after adjusting and first threshold to subtract each other; When described brightness changing value is negative value, the brightness changing value after use adjusting and first threshold addition with renewal brightness changing value; Brightness changing value after use upgrading and current pixel point brightness value with the described sharpened value of renewal.
11. described device is characterized in that according to claim 9, described image analyzing unit comprises:
Second acquisition unit, for the luminance matrix that obtains described input picture, described luminance matrix is comprised of the brightness value of described current pixel point and the brightness value of neighborhood territory pixel point, and described luminance matrix is the matrix of N * M, and described M and N are greater than 2;
The edge filter unit for the edge filter that described luminance matrix is carried out respectively K direction, obtains K direction coefficient of described current pixel point correspondence on K direction;
Comparing unit for the size of a more described K direction coefficient, will be worth maximum direction coefficient as the edge direction coefficient;
Edge counting initialization unit is used for whether judging the edge direction coefficient more than or equal to Second Threshold that if not, then the value initialization with the edge counter is 0; If then the value initialization with the edge counter is 1;
The marginal information output unit, the value of output edge counter.
12. described device is characterized in that according to claim 9, described image analyzing unit also comprises:
The signal characteristic acquiring unit is for brightness maximum and the brightness minimum value of the luminance signal of obtaining input picture;
The signal characteristic output unit is for brightness maximum and the brightness minimum value of exporting described luminance signal.
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| JP5857232B2 (en) * | 2011-11-22 | 2016-02-10 | パナソニックＩｐマネジメント株式会社 | Measuring method, measuring apparatus, camera, computer program and recording medium |
| CN103079038B (en) * | 2013-01-07 | 2016-06-29 | 华为终端有限公司 | Image sharpening processing method, device and camera terminal |
| CN106097286B (en) * | 2016-06-21 | 2019-02-12 | 浙江大华技术股份有限公司 | A kind of method and device of image procossing |
| WO2017219962A1 (en) * | 2016-06-21 | 2017-12-28 | Zhejiang Dahua Technology Co., Ltd. | Systems and methods for image processing |
| CN106846270B (en) | 2017-01-05 | 2020-02-14 | 浙江大华技术股份有限公司 | Image edge enhancement method and device |
| CN111651618B (en) * | 2019-09-26 | 2021-01-15 | 上海麦克风文化传媒有限公司 | Intelligent database management system |
| CN110942440B (en) * | 2019-12-12 | 2023-04-18 | 上海富瀚微电子股份有限公司 | Image sharpening method and device |
| CN112085679B (en) * | 2020-09-08 | 2022-03-22 | 眸芯科技（上海）有限公司 | Width-adjusted edge enhancement processing method and application |
| CN112215237B (en) * | 2020-11-06 | 2023-10-13 | 泰康保险集团股份有限公司 | Image processing method and device, electronic equipment and computer readable storage medium |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101101669A (en) * | 2007-07-13 | 2008-01-09 | 天津大学 | Image reinforcement method for self-adaptive regulation according to edge and brightness |
| CN101132477A (en) * | 2006-08-23 | 2008-02-27 | 原相科技股份有限公司 | Digital image processing method and device thereof |
| CN101197910A (en) * | 2006-12-05 | 2008-06-11 | 广达电脑股份有限公司 | Image sharpening device and method |
| EP2051524A1 (en) * | 2007-10-15 | 2009-04-22 | Panasonic Corporation | Image enhancement considering the prediction error |
-
2010
- 2010-11-23 CN CN 201010555926 patent/CN101980521B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101132477A (en) * | 2006-08-23 | 2008-02-27 | 原相科技股份有限公司 | Digital image processing method and device thereof |
| CN101197910A (en) * | 2006-12-05 | 2008-06-11 | 广达电脑股份有限公司 | Image sharpening device and method |
| CN101101669A (en) * | 2007-07-13 | 2008-01-09 | 天津大学 | Image reinforcement method for self-adaptive regulation according to edge and brightness |
| EP2051524A1 (en) * | 2007-10-15 | 2009-04-22 | Panasonic Corporation | Image enhancement considering the prediction error |
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