CN1910615A - System and methods for comparing images with different contrast levels - Google Patents
System and methods for comparing images with different contrast levels Download PDFInfo
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Abstract
Methodologies and systems to compare images with different levels of contrast are provided. Contrast is normalized between the images with different contrast levels and brightness is set. When normalizing contrast a derivative of gray level is determined for a first digital image having a first contrast level, and a derivative of gray level is determined for a second digital image having a second contrast level that is greater than the first contrast level. A ratio of the derivative of gray level for the first digital image to the derivative of gray level for the second digital image is determined, and the derivative of gray level for the first digital image is equalized with the derivative of gray level for the second digital image. Brightness of at least one image may be set automatically, such as by calculating an average pixel value excluding background and text, or manually.
Description
The cross reference of related application
The application is the non-provisional application of interim (35 USC 119 (e)) application 60/535,358 of submission on January 9th, 2004.
Technical field
The present invention relates generally to a kind of non-destructive evaluation, and relate more specifically to digital radiography.
Background technology
To find defective, for example, such as the hole or the inclusions of bubble or impurity, non-destructive evaluation (NDE) is known for inspection part or material.For example, the x ray is used for the NDE of the manufacture component of system, structure and delivery vehicle (for example boats and ships, land vehicle and such as the aircraft of aircraft and spacecraft) such as piping system.As other more specifically example, because aluminium casting is widely used in aircraft manufacturing, so the inspection cost of the NDE of aluminium casting is represented the quite big number percent of the general inspection cost of aircraft.
This use of x ray is known as " radiography " sometimes.Traditionally, radiography techniques requires checking that the parts of defective are placed between x radiographic source and the silver halide film.Yet traditional silver halide film technical costs is high and time-consuming.
The cost that is associated with traditional silver halide film technology and the reduction of time have been realized by the digital radiography technology.Digital radiography comprises far-ranging technology, and it comprises plate technique, computed radiography art and various technology based on scintillater (scintillator) and digital camera.Transformation, can eliminate and buy film, handle the cost that film and chemical waste disposal are associated from traditional film radiography to digital radiography.In addition, reduction cycle length and robotization by digital radiography provided can realize significant saving.
The main obstruction that the digital radiography realization is used for a large amount of industrial uses is to lack digital reference image.There are a lot of differences in the radiographic images of catching on film with respect to by any radiographic images of catching at present available a lot of digital morphologicals (modalities).As a result, digital radiograph and directly relatively caused between the various digital morphologicals and the different characteristic of the severity level between numeral and the film radiography at the current reference radiography of catching on the film.
Attempted in the industry solving these difference at aluminum casting by converting existing film reference radiography (being used to check the ASTM E155 reference radiography of aluminium and magnesium foundry goods) to digital picture.Yet, can not directly change into the field of digital radiography such as the conventional film reference radiography of ASTM E155.Existing reference radiography is owing to following two main causes have confirmed deficiency: the spatial resolution difference between (1) radiographic film and the digital radiography system; And the difference in dynamic range between (2) film and a lot of digital detector.
About using first shortcoming of existing film reference radiography, the range of size of the granularity of plain radiography film is about 3 microns (μ m) to about 10 μ m, and the scope that is suitable for not utilizing the pixel separation of amplifying the digital radiography system of checking aluminium casting for how much for about 50 μ m to about 139 μ m.As if these differences in resolution do not influence uncontinuity and detect.Yet these differences in resolution influence the classification of the severity level of uncontinuity really.For example, Fig. 1 is with the digitized elongated porosity 1/4 of the pixel separation of 140 μ m " the film radiograph 10 of the third level (plate); Fig. 2 is the film radiograph 20 with the level V of the digitized same train of pixel separation of 50 μ m; And Fig. 3 is only digitized with 50 μ m, identical with film radiograph 10 (Fig. 1) film radiograph 30.By film radiograph 10,20 and 30 more as can be seen, the detector resolution between 50 μ m and the 140 μ m (perhaps, in the case, digitized pixel size) difference causes the skew of approximate two-stage on apparent severity level.
About using second shortcoming of existing film reference radiography, the use that the difference in dynamic range between film and a lot of digital detector shows ASTM E155 reference radiography is not enough for the classification of the severity level of aluminium casting.The wide dynamic range of the digital detector that interrelates with restriction on the number of the recognizable grey level intensity of the mankind makes and is necessary data by the given image of a series of window single-step debugs (stepthrough).At present, this changes brightness (window level) then and carries out to check data by regulate contrast (window width) in series of steps.
When regulating the contrast of the product radiograph that adopts the digital detector acquisition, the shortcoming of this scheme appears.When using high-contrast, uncontinuity looks relatively poor (higher plate number just).When using low contrast, uncontinuity may be not as seen.For example, Fig. 4-6 shows this effect.All images all is from the aluminium 1/4 " single 16 dynamic range digital radiographs of the ASTM E155 part of elongated porosity.Fig. 4 and 6 has the digital radiograph 40 and 60 that same contrast is provided with, and Fig. 5 is in the digital radiograph 50 of higher contrast ratio setting a little.When comparative figures radiograph 40 (Fig. 4) and digital radiograph 50 (Fig. 5),, and, also there is significant difference from identical radiograph even they all are the second level.On the contrary, digital radiograph (Fig. 5) looks and more looks like digital radiograph 60 (Fig. 6).Yet digital radiograph 60 (Fig. 6) is the 7th grade---differ five severity levels (referring to Figure 4 and 5) with the second level.
Owing to the image that can not use known method with respect to parts makes the contrast normalization (normalize) of canonical reference image, so directly relatively be impossible between canonical reference image and the image of component.Therefore, need the exploitation of digital reference image, to catch the saving that digital radiography is provided.Yet, do not have to satisfy needs in the prior art to the method for using the set of number reference picture.
Summary of the invention
Embodiments of the invention provide and have been used for relatively having the method and system of other image of different contrast level.Make contrast normalization between other image of different contrast level having, and brightness is set.Advantageously, embodiments of the invention allow to use the electronic digit reference picture with non-film x radiological survey X system.As a result, use of the present invention can significantly reduce and cost that the time correlation connection is set and the cost that is associated with film, for example is used for the cost of film storage, processing and chemical disposal.And embodiments of the invention can be used for more any digital picture-and be not only the image that obtains by radiography.
In an exemplary application, the electronic digit reference picture allows to use non-film numeral check-up aluminium product foundry goods.When checking the digital radiograph of aluminium casting, digital reference image can be used to substitute current ASTM E155 reference radiography.Advantageously, and use the conventional film radiography of ASTME155 to compare with important mode on statistics, this allows to use the digital radiography of aluminium casting, and need not to change the classification of aluminium casting.
According to embodiments of the invention, relatively has other image of different contrast level.Have normalizing contrast between other image of different contrast level, and brightness is being set.According to an aspect of the present invention, when normalizing contrast, determine derivative of gray level (derivative) at first digital picture, and determine derivative of gray level at second digital picture that has greater than second contrast level of first contrast level with first contrast level.Determine the ratio of the derivative of gray level of the derivative of gray level of first digital picture and second digital picture, and the derivative of gray level of first digital picture and the derivative of gray level of second digital picture are carried out equilibrium (equalize).According to a further aspect in the invention, can be manually or brightness is set automatically.
According to an aspect of the present invention, first digital picture can be a digital reference image, and second digital picture can be by the product digital radiograph of image-forming block.Advantageously, this contrast normalization allows to determine the severity level of uncontinuity---irrelevant with the bit depth of employed digital morphological or digital morphological.Regulate the contrast of reference picture, the contrast of the product image that may generate by the form different with coupling with reference picture.This contrast coupling between reference picture and " the unknown " image allows the meaningful comparison between these two images.
According to each side of the present invention, can determine derivative of gray level with respect to any variable as required.For example, can determine derivative of gray level with respect to thickness.The operator can calculate the grey scale change (for example, on monitor) with respect to the variation in thickness of known materials that is presented at such as in second image of product image.Use approaches or at least two known thickness of drawing together the known materials of the thickness of being paid close attention to into (bracket) are calculated this grey scale change.By calculate such as first image of reference picture with respect to the rate of gray level of thickness and ratio with respect to the rate of gray level of thickness such as second image of product image, standardize.Then, this ratio be multiply by the current image window width such as first image of reference picture, cause the window width of the normalizing contrast between these two images with generation.According to additional aspects of the present invention, can carry out any function of definition derivative of gray level, for example logarithmic function or fitting of a polynomial function.In addition, can use non-homogeneous look-up table.
According to additional aspects of the present invention, can be manually or brightness is set automatically.Can brightness manually be set by regulating window level.Can brightness be set automatically by the average pixel value that background and text have been got rid of in calculating.Then, the mean value with display window is made as the mean value of calculating basically.Alternatively, can be made as the brightest (the highest) pixel value, and lower window edge is made as the darkest (minimum) pixel value, and brightness is set automatically by the upper limit with window.
According to another embodiment of the present invention, provide computer program, it is used for having normalizing contrast between other two images of different contrast level, and is used for being provided with automatically brightness.This computer program advantageously makes processing robotization of the present invention, and promotes to have the comparison of other image of different contrast level.This computer program also promotes to use digital reference image in cost-effective mode in various industry and manufacturing are provided with.
Description of drawings
Fig. 1-the 3rd, the digitized image of the film radiograph of the aluminium inner pore of prior art;
Fig. 4-the 6th, the digital radiograph that the different contrast with aluminium inner pore of prior art is provided with;
Fig. 7 is the process flow diagram according to the exemplary generalized method of the embodiment of the invention;
Fig. 8 is the process flow diagram of the details of method shown in Figure 7;
Fig. 9 is the block scheme that is used for the exemplary host environment of the embodiment of the invention; And
Figure 10-the 13rd is from the screen map of the illustrative computer software program product of the method that realizes Fig. 7 and 8.
Embodiment
As general introduction, embodiments of the invention provide and have been used for relatively having the method and system of other image of different contrast level.Make contrast normalization between other image of different contrast level having, and brightness is set.According to an aspect of the present invention, when making contrast normalization, determine derivative of gray level at first digital picture, and determine derivative of gray level at second digital picture that has greater than second contrast level of first contrast level with first contrast level.Determine the ratio of the derivative of gray level of the derivative of gray level of first digital picture and second digital picture, and the derivative of gray level of first digital picture and the derivative of gray level of second digital picture are carried out equilibrium.According to a further aspect in the invention, can be manually or brightness is set automatically.First digital picture can be a digital reference image, and second digital picture can be the product component image such as digital radiograph.Advantageously, embodiments of the invention allow to use the electronic digit reference picture in the mode of non-film x radiological survey X system (for example digital radiography system).As a result, use of the present invention can significantly reduce and cost that the time correlation connection is set and the cost that is associated with film, for example is used for the cost of film storage, processing and chemical disposal.And embodiments of the invention can be used for relatively having other any digital picture of different contrast level-and be not only the image that obtains by radiography.
The present invention may be embodied as method, computer software program product and system.To set forth the details of the non-limiting example of each embodiment of the present invention below.
With reference to figure 7, be used for relatively having the generalized method 100 of other image of different contrast level in piece 102 beginnings.At piece 103, between image, make contrast normalization.At piece 104, determine derivative of gray level at first digital picture such as reference picture with first contrast level.Can carry out any function of definition derivative of gray level, for example logarithmic function or fitting of a polynomial function.As non-limiting example, reference picture can be a digital reference image, the ASTM E2422 reference picture that is for example proposed etc.Can be according to the needs of concrete application, and determine derivative of gray level with respect to any variable.For example, can determine derivative of gray level with respect to thickness.In application, can determine derivative with respect to thickness such as but not limited to radiography.As other example, employed variable can represent to contrast the mapping variable such as the palette of gray scale when determining derivative.For example, image can represent temperature, highly, density or at the mapping of required any other variable of concrete application.In these images, with respect to temperature, highly, density or any variable of using in concrete the application determine the derivative of gray scale.
At piece 106, determine derivative of gray level at second digital picture that has greater than second contrast level of first contrast level, wherein second digital picture is such as but not limited to by the digital picture of any product component of imaging.Yet second digital picture can be the digital picture at the required any kind of application-specific.As in piece 104, can carry out any function of definition derivative of gray level, for example logarithmic function or fitting of a polynomial function.In one exemplary embodiment, according to the needs of the concrete application digital morphological by any kind product component is carried out digital imagery.As non-limiting example, suitable digital morphological comprises digital radiography.Yet the digital radiography that is adopted can comprise any in the far-ranging technology, and it comprises plate technique, computed radiography art and various technology based on scintillater and digital camera.As in piece 104, can be according to the needs of concrete application and determine derivative of gray level with respect to any variable.In the example of the digital morphological of discussing at piece 106, can determine derivative of gray level with respect to thickness.Yet, as in piece 104, in other is used, with respect to temperature, highly, density or any variable of using in concrete the application determine the derivative of gray scale.
At piece 108, determine the ratio of the derivative of gray level of the derivative of gray level of first digital picture and second digital picture.Can carry out any function of definition, for example logarithmic function or fitting of a polynomial function with respect to the derivative of gray level of thickness.At piece 110, the derivative of gray level of first digital picture and the derivative of gray level of second digital picture are carried out equilibrium.In a non-limiting example, carry out equilibrium by determining that window shines upon.The window mapping is applicable to logarithm gray scale and linear gray scales.Alternatively, can shine upon by rule of thumb predetermined look-up table such as non-homogeneous look-up table.
After piece 103 has been standardized contrast between first digital picture and second digital picture, may be desirably in the operator carry out between the image relatively before regulate the brightness of at least one image.Regulate brightness and can help operator's movement images.Typically, the brightness (first digital picture in the case) that has than the image of low contrast is regulated in expectation.
At piece 111, manually or automatically regulate brightness.Can come with software manual adjustments brightness setting by regulating window level.
Alternatively, at piece 111, can regulate the brightness of arbitrary image or two images as required and automatically.For example, the upper limit of window can be made as the brightest (the highest) pixel value, and lower window edge can be made as the darkest (minimum) pixel value.Alternatively, can brightness be set automatically by the average pixel value that background and text have been got rid of in calculating, and the mean value of the display window average pixel value that is set to calculate.The pixel value of background or text pixel value be can be known as by eliminating, background and text got rid of.Typically, be in the extreme pixel value (just, 0 and 2 of minimum and most significant end of the data area of n bit image
n) be used for background or text.For example, in sixteen bit image, background often is made as zero (0) or 65,535, and text often is made as 65,535 or zero (0).This scheme has guaranteed that text is clear and legible with respect to background, and is provided with irrelevant with employed contrast and brightness.Then, brightness is set, makes the mean value of display window be set to the average pixel value of after having got rid of text and background, having calculated.Brightness need not accurately to be made as the average pixel value of calculating.Brightness can be approx or is made as the average pixel value of calculating basically.For example, the mean value of display window can be arranged near positive and negative (plus-or-minus) scope half of display window width, perhaps can it be set according to the needs of concrete application.
Normalizing contrast and being provided with as required under the situation of brightness between first and second images, the operator can compare between first and second images.Method 100 finishes at piece 112.
With reference now to Fig. 8,, method 200 realizes a preferred embodiment of generalized methods 100 (Fig. 7), and it is used for relatively having first image such as the reference picture of first contrast level and has greater than second image of second contrast level of first contrast level as by the product digital picture of image-forming block.Method 200 is in piece 202 beginnings.At piece 203, normalizing contrast between image.At piece 204, determine at reference picture to change with respect to grey level such as the variation of another variable of thickness with first contrast level.As top discuss at piece 104 (Fig. 7), can be according to the needs of concrete application and choice variable.Because the gray-value variation with respect to such as the variation of the variable of thickness in the reference picture all keeps identical for each reference picture, therefore this value or function are advantageously calculated once, and all are cited for each normalization of this reference picture of use.The reference picture of being discussed at piece 104 (Fig. 7) above being similar to, reference picture can include but not limited to ASTM E2422 reference picture etc.
At piece 206,, and determine to change with respect to grey level such as the variation of the variable of thickness at second image (for example by the digital picture of image-forming block) that has greater than second contrast level of first contrast level.As top discuss at piece 106 (Fig. 7), can be according to the needs of concrete application and choice variable.Use approaches or draws together at least two known thickness into the known materials of the thickness of being paid close attention to, calculates grey level and changes.As non-limiting example, can be aluminium casting by image-forming block.Yet according to the needs of concrete application, these parts can comprise the parts of any kind of making by any manufacturing technology.
At piece 208, determine that the grey level with respect to variable change of reference picture changes and the ratio that is changed by the grey level with respect to variable change of image-forming block.At piece 210, the grey level with respect to variable change of reference picture is changed and be multiply by by the ratio that the grey level with respect to variable change of image-forming block changes the window width of reference picture.To have window width than other image of low contrast level and multiply by this ratio and determine the window mapping, and change to change and carry out equilibrium with grey level with other image of higher contrast level will have grey level than other image of low contrast level.As a result, normalizing contrast at reference picture and between by the digital picture of image-forming block.This allows the operator relatively by the digital picture of image-forming block and reference picture, thereby promotes may be present in by the classification of the severity of any defective in the image-forming block such as hole.
As top discuss at piece 111 (Fig. 7), in some cases, may be desirably in the brightness setting that the operator regulates at least one image before comparing.Typically, may expect to regulate the brightness setting that has than other image of low contrast level.At piece 211,, manually or automatically regulate the brightness setting as required with in the described mode of piece 111 (Fig. 7).
Normalizing contrast and being provided with as required under the situation of brightness between first and second images, the operator can compare between first and second images.Method 200 finishes at piece 212.
With reference now to Fig. 9,, can usage example hosted environment 300 resident (host) be used between digital picture normalizing contrast and/or regulates the brightness setting of digital picture and/or the system 302 of comparative figures image.System 302 advantageously as required and manner of execution 100 (Fig. 7) or method 200 (Fig. 8).In one exemplary embodiment, system 302 comprises computing machine 304, for example personal computer, desk-top computer, large scale computer, workstation, laptop computer, palmtop computer, personal digital assistant etc.System 302 also comprises the storage medium 306 of storing digital reference image.Storage medium 306 can comprise any acceptable storage medium, for example internal hard disk drive, external fixed disk drive, optical disk storage apparatus, CD-ROM, DVD, floppy disk etc.
In an exemplary environments, generate the digital radiograph of parts, and digital radiograph is offered system 302.In known manner, x radiographic source 308 provides the x ray 310 that parts 312 is carried out imaging.The image of digital detector 314 detection parts 312.As mentioned above, the digital radiography that is adopted can comprise any in the far-ranging technology, and it comprises plate technique, computed radiography art and various technology based on scintillater and digital camera.Digital detector 314 will be offered computing machine 304 by the digital picture of image-forming block 312.Yet the digital picture that offers computing machine 304 can be the digital picture at the required any kind of concrete application.
With reference now to Figure 10-13,, a kind of computer software program product is carried out by computing machine 304 (Fig. 9), with manner of execution 100 or 200 (Fig. 7 and 8).With reference to Figure 10, show two screens 400 and 410 side by side.As required, screen 400 and 410 can be presented on identical monitor or the independent monitor.Screen 400 shows reference picture.As non-limiting example, reference picture is used for the gas hole defect in 1/4 inch thick aluminium.Reference picture comprises the step (step wedge) that the severity that is used for defective carries out eight grades of classification and has the thickness of 0.150 inch, 0.200 inch, 0.250 inch, 0.300 inch, 0.400 inch and 0.500 inch.Screen 410 shows by the digital radiograph of image-forming block.As non-limiting example, shown in parts are aluminum cast angle bracket.Comprised two areas of porosity defects by image-forming block, it shows as the interior foam or the bubble domain of gray area of these parts.To these areas of porosity defects and the reference picture in the digital radiograph be compared.
Pull-down menu under " digital radiography " comprises " DR line chart statistics ", " DR line chart ", " pixel size ", " contrast calibration 1/4 " and " contrast calibration 3/4 " option." DR line chart statistics " and " DR line chart " option be selection wire and generation line chart separately." pixel size " option allows the input pixel size, and allows to carry out the point-to-point measurement." contrast calibration 1/4 " selects the thickness such as but not limited to the material of aluminium between will be at the 0-1/2 inch of its normalizing contrast.In addition, the thickness at these grades shown in the reference picture is set as 1/4 inch.Similarly, " contrast calibration 3/4 " selects the thickness such as but not limited to the material of aluminium between will be at the 1/2-2 inch of its normalizing contrast.In addition, the thickness at these grades shown in the reference picture is set as 3/4 inch.Parts in this example on thickness less than 1/2 inch, thereby select " contrast calibration 1/4 ".
When selecting " contrast calibration 1/4 ", generate the screen 420 and 430 of Figure 11.For example by with click with drag, click " the 1st step " radio button and draw together into thickness and draw frame with the 1st step of screen 430.Analyze the pixel of being painted in the frame and be used for statistics.The statistics of being paid close attention to be at 0.150 inch the 1st the step thickness the average gray level value.This is because the grey level value that the 1st step thickness of this average gray level value and 0.150 inch will be used for calculating with respect to thickness changes or grey level value derivative.
Click " the 2nd step " radio button and draw together into thickness, and generate the screen 440 and 450 of Figure 12 to select next.In the 2nd step thickness of screen 450, draw frame.The pixel of analyzing in institute's frame of painting is used for adding up.Equally, the statistics of being paid close attention to be at 0.200 inch the 2nd the step thickness the average gray level value.
Click " calibration " button, and generate the screen 460 and 470 of Figure 13.Screen 460 expression reference pictures, and screen 470 expressions are by the digital radiograph of image-forming block.When click " calibration " button, change at the screen 460 and the average gray level in the 1st step of 470 calculating and the 2nd step respectively, and go on foot thickness and the 2nd variation in thickness that goes on foot between the thickness divided by the 1st at screen 460 and 470.By the result of screen 460 is determined ratio divided by the result of screen 470.At as described in the method 200 (Fig. 8), this ratio be multiply by the window width of reference picture (that is, screen 460) as top.As a result, the contrast by the reference picture shown in contrast between the digital radiograph of image-forming block and the screen 460 shown in the screen 470 is standardized.By relatively eight grades shown in the screen 440 (Figure 12) and eight grades shown in the screen 460, feel this contrast normalization significantly.Shown in the non-limiting example, the hole defective shown in the screen 470 is with suitable in the hole defective shown in the 3rd level of the reference picture shown in the screen 460 or the 4th grade.Under the situation that does not have the contrast normalization between digital radiograph and the reference picture, just can not carry out such comparison.For example, temporarily get back to Figure 12, any in eight grades shown in the reference picture of digital radiograph shown in the screen 450 and screen 440 relatively will be insignificant.Advantageously, as the result of the contrast normalization between digital radiograph and the reference picture, can carry out the direct comparison between digital radiograph and the reference picture now.
Typically, computer program instructions can be loaded on computing machine or other programmable device, to produce machine, so that the instruction of carrying out on computing machine or other programmable device is configured for being implemented in the device of the function of appointment in process flow diagram or screen segment or the step.These computer program instructions can also be stored in can vectoring computer or the computer-readable memory of other programmable device with ad hoc fashion work in produce and comprise the product that is implemented in the command device of the function of appointment in process flow diagram or screen segment or the step so that be stored in instruction in the computer-readable memory.These computer program instructions can also be loaded on computing machine or other programmable device, so that on computing machine or other programmable device, carry out the sequence of operations step, thereby produce computer implemented processing, on computing machine or other programmable device so that the instruction of carrying out is provided for being implemented in the step of the function of appointment in process flow diagram or screen segment or the step.
Thereby each piece of process flow diagram or screen map or step support are used to the combination carrying out the device of appointed function and be used to carry out the program instruction means of appointed function.The combination that it is also understood that the piece of each piece of process flow diagram or screen map or step and process flow diagram or screen map or step can be by carrying out realizing based on the computer system of specialized hardware or the combination of specialized hardware and computer instruction of appointed function or step.
Though illustrate and described the preferred embodiments of the present invention as mentioned above, under the situation that does not break away from the spirit and scope of the present invention, can much change.Thereby scope of the present invention is not subject to the disclosure of preferred embodiment.On the contrary, should determine the present invention with reference to claims fully.
Claims (37)
1. the method for a comparative figures image, this method comprises:
Normalizing contrast in first digital picture and between having greater than second digital picture of second contrast level of first contrast level with first contrast level; And
Regulate at least one the brightness setting in first and second digital pictures.
2. the method for claim 1, wherein the step of normalizing contrast comprises:
Determine the derivative of gray level of first digital picture;
Determine the derivative of gray level of second digital picture;
Determine the ratio of the derivative of gray level of the derivative of gray level of first digital picture and second digital picture; And
The derivative of gray level of first digital picture and the derivative of gray level of second digital picture are carried out equilibrium.
3. the method for claim 1 is wherein regulated the brightness setting with a kind of execution in manual and automatic.
4. method as claimed in claim 3, the step of wherein regulating the brightness setting automatically comprises:
Text in the rejection image window and background;
Calculate the average pixel value of having got rid of text and background at image window; And
The average pixel value of image window is made as the average pixel value of calculating.
5. system that is used for the comparative figures image, this system comprises:
Memory storage is configured to store at least first digital picture with first contrast level;
Input interface is configured to import at least second digital picture that has greater than second contrast level of first contrast level;
Processor comprises:
First assembly is configured to normalizing contrast between first digital picture and second digital picture; And
Second assembly is configured to regulate at least one the brightness setting in first and second digital pictures.
6. system as claimed in claim 5, wherein this first assembly also is configured to:
Determine the derivative of gray level of first digital picture;
Determine the derivative of gray level of second digital picture;
Determine the ratio of the derivative of gray level of the derivative of gray level of first digital picture and second digital picture; And
The derivative of gray level of first digital picture and the derivative of gray level of second digital picture are carried out equilibrium.
7. system as claimed in claim 5, wherein this second assembly also is configured to regulate the brightness setting automatically by following operation:
Text in the rejection image window and background;
Calculate the average pixel value of having got rid of text and background at image window; And
The average pixel value of image window is made as the average pixel value of calculating.
8. computer software program product that is used for the comparative figures image, this computer software program product comprises:
The first computer software programs code device is used in first digital picture with first contrast level and normalizing contrast between having greater than second digital picture of second contrast level of first contrast level; And
The second computer software programs code device is used for regulating at least one brightness setting of first and second digital pictures.
9. computer software program product as claimed in claim 8, wherein this first computer software programs code device comprises:
The 3rd computer software programs code device is used for determining the derivative of gray level of first digital picture;
The 4th computer software programs code device is used for determining the derivative of gray level of second digital picture;
The 5th computer software programs code device is used for determining the ratio of the derivative of gray level of the derivative of gray level of first digital picture and second digital picture; And
The 6th computer software programs code device is used for the derivative of gray level of first digital picture and the derivative of gray level of second digital picture are carried out equilibrium.
10. computer software program product as claimed in claim 8, wherein this second computer software programs code device comprises:
The 7th computer software programs code device is used for the text and the background of rejection image window;
The 8th computer software programs code device is used for calculating the average pixel value of having got rid of text and background at image window; And
The 9th computer software programs code device is used for the average pixel value of image window is made as the average pixel value of calculating.
11. the method for a normalizing contrast between digital picture, this method comprises:
Determine to have the derivative of gray level of first digital picture of first contrast level;
Determine to have derivative of gray level greater than second digital picture of second contrast level of first contrast level;
Determine the ratio of the derivative of gray level of the derivative of gray level of first digital picture and second digital picture; And
The derivative of gray level of first digital picture and the derivative of gray level of second digital picture are carried out equilibrium.
12. method as claimed in claim 11, wherein this equalization step comprises definite window mapping.
13. method as claimed in claim 12, wherein definite window mapping steps comprise that the ratio with the derivative of gray level of the derivative of gray level of first digital picture and second digital picture multiply by the window width of first digital picture.
14. method as claimed in claim 11, wherein this equalization step comprises the visit look-up table.
15. method as claimed in claim 14, wherein this look-up table is non-linear.
16. method as claimed in claim 11, wherein the step of definite derivative is determined the function of definition derivative, and this function comprises in logarithmic function and the fitting of a polynomial function.
17. method as claimed in claim 11, wherein the step of definite derivative is determined the derivative with respect to thickness.
18. a system that is used for normalizing contrast between digital picture, this system comprises:
Memory storage is configured to store at least first digital picture with first contrast level;
Input interface is configured to import at least second digital picture that has greater than second contrast level of first contrast level;
Processor comprises:
First assembly is configured to determine the derivative of gray level of first digital picture;
Second assembly is configured to determine the derivative of gray level of second digital picture;
The 3rd assembly is configured to determine the ratio of the derivative of gray level of the derivative of gray level of first digital picture and second digital picture; And
The 4th assembly is configured to the derivative of gray level of first digital picture and the derivative of gray level of second digital picture are carried out equilibrium.
19. system as claimed in claim 18, wherein the 4th assembly also is configured to determine the window mapping.
20. system as claimed in claim 19, wherein the 4th assembly also is configured to the ratio of the derivative of gray level of the derivative of gray level of first digital picture and second digital picture be multiply by the window width of first digital picture.
21. system as claimed in claim 18, wherein the 4th assembly also is configured to visit look-up table.
22. system as claimed in claim 21, wherein this look-up table is non-linear.
23. system as claimed in claim 18, wherein said first and second assemblies also are configured to determine the function of definition derivative, and this function comprises in logarithmic function and the fitting of a polynomial function.
24. system as claimed in claim 18, wherein said first and second assemblies also are configured to definite derivative with respect to thickness.
25. a computer software program product that is used for normalizing contrast between digital picture, this computer software program product comprises:
The first computer software programs code device is used to determine have the derivative of gray level of first digital picture of first contrast level;
The second computer software programs code device is used to determine to have the derivative of gray level greater than second digital picture of second contrast level of first contrast level;
The 3rd computer software programs code device is used for determining the ratio of the derivative of gray level of the derivative of gray level of first digital picture and second digital picture; And
The 4th computer software programs code device is used for the derivative of gray level of first digital picture and the derivative of gray level of second digital picture are carried out equilibrium.
26. computer software program product as claimed in claim 25, wherein the 4th computer software programs code device also is configured to determine the window mapping.
27. computer software program product as claimed in claim 26, wherein the 4th computer software programs code device window width that is configured to multiply by by the ratio with the derivative of gray level of the derivative of gray level of first digital picture and second digital picture first digital picture is determined the window mapping.
28. computer software program product as claimed in claim 25, wherein the 4th computer software programs code device also is configured to visit look-up table.
29. computer software program product as claimed in claim 28, wherein this look-up table is non-linear.
30. computer software program product as claimed in claim 25, the wherein said first and second computer software programs code devices also are configured to determine the function of definition derivative, this function comprises in logarithmic function and the fitting of a polynomial function.
31. computer software program product as claimed in claim 25, the wherein said first and second computer software programs code devices also are configured to definite derivative with respect to thickness.
32. a method of regulating the brightness setting of digital picture automatically, this method comprises:
Input picture;
Text in the rejection image and background;
The average pixel value of having got rid of text and background at image calculation; And
The brightness setting is made as basically the average pixel value of calculating.
33. method as claimed in claim 32, wherein:
This image is the n bit image;
Background in this image has one pixel value of the minimum and most significant end of the data area that is arranged in the n bit image; And
Text in this image has another pixel value of the highest and least significant end of the data area that is arranged in the n bit image.
34. the system that the brightness that is used for regulating automatically digital picture is provided with, this system comprises:
Input interface is configured to input picture; And
Processor comprises:
First assembly is configured to text and background in the rejection image;
Second assembly is configured to get rid of at image calculation the average pixel value of text and background; And
The 3rd assembly is configured to the brightness setting is made as the average pixel value of calculating basically.
35. system as claimed in claim 34, wherein:
This image is the n bit image;
Background in this image has one pixel value of the minimum and most significant end of the data area that is arranged in the n bit image; And
Text in this image has another pixel value of the highest and least significant end of the data area that is arranged in the n bit image.
36. the computer software program product that the brightness that is used for regulating automatically digital picture is provided with, this computer software program product comprises:
The first computer software programs code device is used for the text and the background of rejection image;
The second computer software programs code device is used for having got rid of at image calculation the average pixel value of text and background; And
The 3rd computer software programs code device is used for the brightness setting is made as the average pixel value of calculating basically.
37. computer software program product as claimed in claim 36, wherein:
This image is the n bit image;
Background in this image has one pixel value of the minimum and most significant end of the data area that is arranged in the n bit image; And
Text in this image has another pixel value of the highest and least significant end of the data area that is arranged in the n bit image.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US53535804P | 2004-01-09 | 2004-01-09 | |
| US60/535,358 | 2004-01-09 | ||
| US11/018,840 | 2004-12-21 |
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| Publication Number | Publication Date |
|---|---|
| CN1910615A true CN1910615A (en) | 2007-02-07 |
| CN100573583C CN100573583C (en) | 2009-12-23 |
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| CNB200580002151XA Active CN100573583C (en) | 2004-01-09 | 2005-01-06 | Be used for relatively having the system and method for other image of different contrast level |
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| CN (1) | CN100573583C (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103544931A (en) * | 2013-10-12 | 2014-01-29 | Tcl集团股份有限公司 | Character generating method and device and application terminal |
| CN103842847A (en) * | 2012-09-28 | 2014-06-04 | 株式会社东芝 | Nuclear medicine diagnostic device, image diagnostic device, and image processing method |
| CN106485652A (en) * | 2016-10-12 | 2017-03-08 | 青岛海信电器股份有限公司 | Setting contrast method and device |
-
2005
- 2005-01-06 CN CNB200580002151XA patent/CN100573583C/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103842847A (en) * | 2012-09-28 | 2014-06-04 | 株式会社东芝 | Nuclear medicine diagnostic device, image diagnostic device, and image processing method |
| CN103842847B (en) * | 2012-09-28 | 2016-04-27 | 株式会社东芝 | Nuclear medicine diagnostic apparatus, image diagnosing system and image processing method |
| CN103544931A (en) * | 2013-10-12 | 2014-01-29 | Tcl集团股份有限公司 | Character generating method and device and application terminal |
| CN106485652A (en) * | 2016-10-12 | 2017-03-08 | 青岛海信电器股份有限公司 | Setting contrast method and device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN100573583C (en) | 2009-12-23 |
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