Abstract:
A method for processing image fields is provided. The method includes determining similarities of first data lines of a first plurality of couples of fields among a plurality of fields by detecting similarities of pixels of the first data lines of the first plurality of couples of fields, and generating television image signals relative to the first data lines of a plurality of couples of adjacent fields among the plurality of fields by utilizing the first data lines of the plurality of couples of adjacent fields according to a predetermined rule when a first predetermined pattern is detected from said similarities of said first data lines of the first plurality of couples of fields.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     The application claims the benefit of U.S. Provisional Application No. 60/560,621 which was filed on Apr. 9, 2004. 
     
    
     BACKGROUND OF INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The invention relates to a method for generating TV signals and related apparatus, and more particularly, to a method for generating TV signals according to data lines similarities and related apparatus thereof.  
         [0004]     2. Description of the Prior Art  
         [0005]     The continuous and dynamic images of movies and television provided to viewers are in reality generated from a combination of gradually changing still images. When the television displays the video, there are two types of systems that have evolved to produce the continuous and dynamic flow of images. The first one is the national television standard committee (NTSC) system. In this system each video field includes 525 rows of data (i.e., 525 horizontal lines) and 60 pictures are displayed each second, i.e. the field rate is 60 Hz. The second system is called the phase alternating line (PAL), wherein each video field includes 625 rows of data and 50 pictures are displayed each second, i.e. the field rate is 50 Hz. For these two traditional television systems, to display 60 fields per second comprising 525 rows of data or to display 50 fields per second comprising 625 rows of data is extremely expensive, thus not suitable to the market. So, interlaced scanning technology was developed. Interlaced scanning scans the even lines for the first video field, then scans the odd lines for the next video field instead of scanning all lines for each field. Hence, for NTSC system with 60 Hz field rate actually 30 frames per second are processed, and for PAL system actually 25 frames per second are processed. However, the flow of dynamic images is still acceptable to the human eye. The images are still perceived as continuous and dynamic. Each frame in the interlaced scanning technology is divided into two parts: odd sequence data that is known as odd field and even sequence data that is known as even field.  
         [0006]     However, a movie is displayed at a frame rate of 24 Hz. For NTSC system, as an example, when it is desirable to broadcast the movie to the television the movie&#39;s image data must be converted from its normal frequency of 24 Hz to 60 Hz.  
         [0007]     Please refer to  FIG. 1 , which shows a comparison of the original film frames and interlaced TV fields. The upper part of  FIG. 1  shows the original film frames A, B, C, and D, and the lower part of  FIG. 1  shows 10 interlaced TV fields F 1 -F 10  generated from the original film frames A, B, C, and D. For example, the odd lines of the film frame A associates with the TV fields F 1  and F 3 . Furthermore, the even lines of the film frame A associates with the TV field F 2 , wherein A o  and A e  represent the odd field and the even field generated from the film frame A, respectively. Similarly, Be and Bo represent the even field and odd field from the film frame B. Ce and Co represent the even field and odd field from the film frame C. De and Do represent the even field and odd field from the film frame D. So, the frame rate of the film is 24 Hz, but the field rate of the NTSC system is 60 Hz. In other words, two film frames are transformed into five TV fields, so-called three to two pull down conversion, to comply with the NTSC system. Therefore, the total data amount is halved and the odd and even fields are displayed in the interlaced way.  
         [0008]     Progressive scan is developed later and becomes popular, such as the LCD display or plasma TV. In progressive scan, the whole data lines, instead of only half data lines, of each video field are displayed. Therefore, when the progressive scan (or the double-frequency TV image technique) is utilized to display the field, which only comprise half data, fields should be transformed into frames, which comprise the whole data, so that the progressive scan can be executed correctly. The above-mentioned operation of transforming fields into frames is also called as “de-interlacing” technique. Generally speaking, two odd (even) fields corresponding to the same film frame are the same, but two odd (even) fields corresponding to two film frames are the same only if the two film frames are still. In the prior art, one field can be deinterlaced with the adjacent field to double the display resolution. However, if the original field data are the fields of film data as shown in  FIG. 1 , a serious problem occurs when the third field Ao and the fourth field Be are combined because the field Ao and the field Be correspond to different frames. Therefore, if the interlaced TV fields come from the film data, only the first pair of odd (even) fields is the same per five odd (even) fields.  
         [0009]     Please refer to  FIG. 2 , which is a diagram of generating progressive TV frames. When we find that the fields F 1  and F 3  are the same and the fields F 6  and F 8  are the same, the source image data can be determined to be a film image. Therefore, the odd field F 1  and the even field F 2  can be combined as a progressive TV frame P 1 , which is labeled as A′. Similarly, the progressive TV frame P 4 , P 6 , and P 9  are respectively labeled as B′, C′, and D′.  
         [0010]     In the NTSC system, the frame rate of the progressive scan technique is 60 Hz. Therefore, the progressive TV frame P 1  is utilized to generate the progressive TV frames P 2  and P 3 . In other words, the progressive TV frame A′ is displayed in total three times. Similarly, the progressive TV frames P 4  are copied to generate the progressive TV frame P 5 . That is, the progressive TV frame B′ is displayed twice. Similarly, the frame C′ is displayed three times, and the frame D′ is displayed twice.  
         [0011]     When the TV data are broadcasted by the TV service provider, other data or information (for example, running text) is added to facilitate advertisements or news. Because of the introducing this additional data or information, two same fields looks different. If two same fields originates from the same film frame, the prior art may wrongly determine the mode of the TV content or wrongly processing the fields results in the running text becoming blurred.  
         [0012]     In addition to adding the running text, other information can be added such that the original similarity pattern is influenced. For example, a still text or trademark is added, or the current time text can be added in the corner of the picture. These may cause a misinterpretation of the type of the source image. Please refer to  FIG. 3 , which shows a TV field sequence comprising still texts during a time period. As shown in  FIG. 3 , the fields F 11 -F 20  are generated from film frames E, F, G, and H. The TV service provider adds a still text (e.g., a trademark of the TV service provider) in the fields F 12 -F 17 . Therefore, interlaced TV fields F 11 -F 20  can be orderly shown as Eo, Ee′, Eo′, Fe′, Fo′, Ge′, Go′, Ge′, Ho, He, wherein the label ′ represents that the field comprises the above-mentioned still text. Most TV service providers do not notice the 3:2 pull-down ratio relationships between the film frames and the interlaced TV fields while adding additional text, A sudden text shadow between the successive even and odd fields on TV screen may occur (e.g., between the fields Eo and Ee′ and between the fields Go and Ge′, where the still text is only added in one field of two successive fields). This cause the wrong determination of the mode of the TV content. If the fields are processed, the added texted area of the image becomes blurred. Alternatively, if we do notthing, the image quality becomes poor.  
       SUMMARY OF INVENTION  
       [0013]     It is therefore one of primary objectives of the claimed invention to provide a method for generating a TV signal according to data line similarity and the related apparatus thereof. That is, the present invention utilizes the data line as a unit to detect the similarity of each pair of fields, and then utilizes the similarity pattern to determine the type of the source image. Therefore, the present invention utilizes the data line as a unit to process the interlaced TV data to generate the progressive TV data in order to prevent the influence of the similarity pattern from having a negative effect on the added running texts or still texts in order to solve the above-mentioned problem.  
         [0014]     According to an exemplary embodiment of the claimed invention, a method for generating image signals according to data lines similarity is disclosed. The method comprises: determining similarities of first data lines by detecting similarities of pixel similarities of the first data lines of a first plurality of pairs of fields among a plurality of fields; and if the similarities of the first data lines comply with a first predetermined similarity pattern, utilizing first data lines of a plurality pairs of successive fields of the plurality of fields according to a predetermined rule in order to generate data of a first data line of a image signal, where the data of the first data line of the image signal correspond to the plurality pairs of successive fields.  
         [0015]     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0016]      FIG. 1  is a diagram of comparisons of TV fields and original film frames according to the prior art.  
         [0017]      FIG. 2  is a diagram of generating progressive TV frames according to the prior art.  
         [0018]      FIG. 3  is a diagram of TV fields that have still texts added in a time period according to the prior art.  
         [0019]      FIG. 4  shows interlaced TV fields F 41 -F 52  comprising running texts according to the present invention.  
         [0020]      FIG. 5  is a diagram of an interlaced TV field sequence according to the present invention.  
         [0021]      FIG. 6  is a flow chart of detecting the similarity of two data lines according to the present invention.  
         [0022]      FIG. 7  is a diagram of a similarity detection device  700  of an embodiment according to the present invention.  
         [0023]      FIG. 8  is a diagram of interlaced TV fields F 81 -F 90  comprising still texts according to the present invention.  
         [0024]      FIG. 9  is a diagram of an interlaced field sequence according to the present invention.  
         [0025]      FIG. 10  is a flow chart of detecting the similarity between an odd field and an even field.  
         [0026]      FIG. 11  is a circuit diagram of a field similarity detection device according to the present invention.  
         [0027]      FIG. 12  shows interlaced TV fields F 121 -F 128  generated from TV frames instead of film frames.  
         [0028]      FIG. 13  is a diagram of a display controller of an embodiment according to the present invention.  
         [0029]      FIG. 14  is a flow chart of selectively performing the de-interlacing operation and the scaling operation according to detected similarities. 
     
    
     DETAILED DESCRIPTION  
       [0030]     The present invention utilizes data lines as a unit (line-based) to detect similarities of specific data lines of each field in an interlaced TV signal. If the similarities of the specific data lines comply with a predetermined similarity pattern, the present invention combines data of the specific data lines of two successive fields to generate a progressive TV signal. On the other hand, if the similarities of the specific data lines do not comply with the predetermined similarity pattern, the present invention directly interpolates the data lines utilizing the current field, to enhance the quality for the progressive TV signal.  
         [0031]     Please refer to  FIG. 4 , which shows interlaced TV fields F 41 -F 52  comprising running texts and shows the relationship between the film frames I-M and the interlaced fields F 41 -F 52 . The TV service provider adds a running text between the n+2 data line and the s+1 data line. Please note the range of the running text in odd and even fields is diferred by one data line. For example, the fields F 41  and F 43  originate from the odd lines of the film frame, and the running text (this is shown as slope lines in  FIG. 4 ) is added between the n+2 data line and the s data line. The odd field F 51  and the even field F 52  originate from the film frame M. The y th  line of the field X is labeled as X(y). In this embodiment, two fields, which have a field between them (for example, the fields F 41  and F 43 ), are regarded as a pair of corresponding fields. Furthermore, a data line is utilized as a unit to respectively detect the similarities of corresponding data lines of the pair of corresponding fields. And then, the similarities of the data lines are compared with a specific pattern. For example, the first data line of the field F 41  is compared with the first data line of the field, the second data line of the field F 42  is compared with the second data line of the field F 44 . It is known that if the pair of corresponding fields both originate from the same film frame and are odd (even) fields, the pair of corresponding fields is quite similar. Therefore, if the pixels&#39; difference between the pair of corresponding fields is less than a predetermined number, the pair of corresponding fields is determined as being similar. As mentioned above, it can be seen that the first data line of the field F 41  and the first data line of the field F 43  are similar, and the second data line of the field F 46  and the second data line of the field F 48  are similar. Therefore, the present invention determines that the interlaced TV fields comply with a specific similarity pattern because of the above-mentioned characteristic. And the present invention can know that the first lines and the second lines of the above-mentioned TV fields come from the film frames. As shown in  FIG. 4 , for example, the first data line of the interlaced TV field F 41  and the second data line of the interlaced TV field F 42  can be deinterlaced to generate the first and the second data lines of the progressive TV frames P 41  and P 42 . Similarly, when comparing the third data line and the fourth data line of the pair of the corresponding fields among the fields F 41 -F 52 , the present invention detects that the third data lines of the fields F 41  and F 43  are similar and the fourth data lines of the field F 46  and the field F 48  are similar. Therefore, the present invention can determine that the third and fourth data lines of the TV fields also come from the film frames. Therefore, the present invention can utilize the third data lines and the fourth data lines to generate the third and fourth data lines of wanted frames. For example, the present invention can utilize the fourth data line of the field F 44  and the third data line of the field F 45  to generate the third and fourth data lines of the progressive TV frames P 44  and P 45 .  
         [0032]     In this embodiment, the present invention can detect a similarity pattern of data lines of the interlaced scanning television image signal in the data lines, which are above the n+2 data line or below the s data line in odd fields among the fields F 41  to F 50 , and in the data lines, which are above the n+3 data line or below the s+1 data line in even fields among the fields F 41  to F 50 . The similarity, as mentioned above, indicates that the two fields of the first pair of fields among five successive pairs of fields are similar to each other, wherein each pair of fields contains two fields that are separated by a single field. And if the similarity complies with the similarity pattern, the data line is utilized as a unit to combine the odd field and the even field to generate corresponding data lines of TV frames P 41 -P 50 . This allows that the data of the 1 data line to n+1 data line, and data of the data lines below the s+2 data lines are double of the original interlaced TV field so as to have better display quality.  
         [0033]     However, because the running text is added in the interlaced TV fields F 41 -F 50 , the similarities of the n+2 data lines of the fields F 41 -F 50  to s+1 data lines of the fields F 41 -F 50  do not comply with the specific similarity pattern. Therefore, the present invention directly utilizes neighboring data lines of the current field to generate two data lines of the progressive frames.  
         [0034]     As shown in  FIG. 4 , the data lines of interlaced TV field F 41  are utilized to generate the odd lines of the first data line to n data line of the frame P 41 . And the data lines of interlaced TV field are utilized to generate the even lines of the second data line to the n+1 data lines of the frame P 41 . The data of n+2 data line to the s data line of the interlaced TV field F 41  are utilized to generate the data lines from the n+2 data lines to s+1 data lines (each data line of the n+2 data line to the s+1 data line) of the frame P 41  (for example, the data lines of the field F 41  can be interlaced themselves or repeatedly outputted to generate corresponding data lines of the frame) because the similarity does not comply with the specific pattern. For example, the n+2 data line of the field F 41  is utilized as the n+2 data line and the n+3 data line of the frame P 41 . From the s+2 data line, because there is no running text added, these data lines of the interlaced TV fields have the similarity pattern of the film frame again, so the field F 41  and the field F 42  are deinterlaced to generate the data lines of the frame P 41  therebetween.  
         [0035]     In this embodiment, if detecting that the similarities of corresponding data lines of fields comply with the specific similarity pattern for several times (for example, the specific similarity pattern of the data lines of the pair of corresponding fields per five fields appears twice), the present invention combines the data of the data lines of the interlaced TV fields into the corresponding data lines of the progressive TV frames according to a predetermined way. Please note that when the data are displayed, if the similarity pattern cannot be detected, the present invention directly utilizes the data lines of the fields to generate progressive TV data instead of utilizing the combined data line.  
         [0036]     Please refer to  FIG. 5 , which is a diagram of an interlaced TV field sequence. As shown in  FIG. 5 , the z th  pixel of the y th  of the X data line is labeled as X(y,z). In this embodiment, the gray level value of pixels of two corresponding lines of a pair of corresponding fields are compared, and the comparison results are utilized to determine whether the two data lines are similar. For example, if the pixel  51 ( g, j ), j pixel of g data line of the field F 51 , is a target pixel, the pixel  53 ( g , j) is compared with the pixel  51 ( g, j ). In addition, if the gray value of the pixel  51 ( g, j ) is different from the gray value of the pixel  53 ( g, j ) or the difference between the gray values of the pixels  51 ( g, j ) and  53 ( g , j) is larger than a predetermined value K1 (considering the noise), the pixel  51 ( g, j ) is regarded as being different from the corresponding pixel  53 ( g, j ). Furthermore, if the number of pixels, which are detected as being different from corresponding pixels, of the g data line of the field F 51  is less than a predetermined number K2, the present invention determines that the g data line of the field F 51  is similar to the g data line of the field F 53 . Conversely, if the number of pixels, which are detected as being different from corresponding pixels, of the g data line of the field F 51  is larger than a predetermined number K2, the present invention determines that the g data line of the field F 51  is not similar to the g data line of the field F 53 .  
         [0037]     Please refer to  FIG. 6 , which is a flow chart of detecting the similarity of two data lines, wherein the field to be detected is called as a target field, and the other field is a corresponding field. And the flow chart comprises following steps: 
        Step  600 : Set N=0;     Step  610 : If all pixels of a target data line of the target field are all detected, step  615  is then performed; otherwise, step  620  is performed;     Step  615 : Determine that the target data line of the target field is similar to the corresponding data line of the corresponding field, and then step  670  is performed;     Step  620 : Determine an undetected pixel of the target data line of the target field as the target pixel and determine a corresponding pixel, which has a position, which corresponds to the target pixel, of the corresponding data line of the corresponding field;     Step  630 : If the gray value of the corresponding pixel is different from the gray value of the target pixel, step  640  is performed; otherwise, step  610  is performed;     Step  640 : Add 1 to N;     Step  650 : If N is larger than the predetermined value K, then step  660  is performed; otherwise, step  610  is performed again;     Step  660 : Determine that the target data line of the target field is not similar to the corresponding data line of the corresponding field;     Step  670 : Finish.        
 
         [0047]     In order to realize the flow of determining the similarity of two data lines, the image processing device can be embodied by software or hardware circuits.  
         [0048]     Please refer to  FIG. 7 , which is a diagram of a similarity detection device  700  of an embodiment according to the present invention. The similarity detection device  700  comprises the pixel comparator  710 , an adder  740 , and a similarity determiner  750 . The similarity detection device  700  can detect the similarities of two data lines of two odd fields or two even fields. For example, if the target pixel is the j pixel of the g data line of the target field, the corresponding pixel can be the j pixel of the g data line of the corresponding field. The pixel comparator  710  determines the gray value difference between the target pixel of the target field and the corresponding pixel of the corresponding field in order to detect whether the target pixel is similar to the corresponding pixel. The pixel comparator  710  comprises a pixel processing module  720  for calculating the absolute value of the gray value difference between the target pixel and the corresponding pixel. The pixel processing module  720  comprises a subtraction unit  722  for calculating the gray value difference between the target pixel and the corresponding pixel, and an absolute value unit  724  for outputting an absolute value of the gray value difference. In addition, the pixel comparator  710  further comprises the comparison unit  730 , coupled to the absolute unit  724  of the pixel processing module  720 , for comparing the gray value difference with a predetermined value K1. If the gray value difference is larger than the predetermined value K1, the comparator unit  730  outputs a value 1. On the other hand, if the gray value difference is less than the predetermined value K1, the comparison unit  730  outputs a value 0. The adder  740 , coupled to the outputting end of the comparison unit  730 , comprises the adder  742  and the buffer  744  for performing an adding operation on the output of the comparison unit  730 . In this embodiment, if the gray value difference is larger than the predetermined value K1, the pixel comparator  710  outputs the value 1 to the adder  740 . This represents that the target pixel is not similar to the corresponding pixels. Otherwise, the pixel comparator  710  outputs the value 0 to the adder  740 . Therefore, if pixels of the target data line of the target field are orderly set as the target pixel, and are compared with their corresponding pixels, the pixel comparator  710  outputs the value 1 or 0 to the adder  740  according to different situations. The similarity determiner  750 , coupled to the output end of the adder  740 , for determining that the target data line of the target field is not similar to the corresponding data line of the corresponding field if the adding result of the adder  740  is larger than the predetermined number K2.  
         [0049]     Please note that when the interlaced TV fields comprise still texts, the present invention detectd the line-based similarities in order to generate the progressive TV frames. Please refer to  FIG. 8 , which is a diagram of interlaced TV fields F 81 -F 90  comprising still texts. Fields F 81 , F 83 , F 85 , F 87 , and F 89  are odd fields, the others are even fields. In this embodiment, the n+2 data line to s+1 data line of the fields F 82  to F 87  comprises additional still texts. Please note that the range of the still texts of the odd and even field differs by one data line. For example, the n+3 data line to the s+1 data line of the field F 84  comprise the still texts, the n+2 data line to the s data line of the field F 85  comprise the still texts; wherein the y data line of the X field is labeled as X(y), and the area of still texts are shown as slope lines. In this embodiment, the similarity of corresponding data lines of the pair of corresponding fields of fields F 81  to F 90  are detected. And then the similarity is compared with a specific pattern. Because the content of odd (even) fields corresponding to the same film frame are similar, the data lines of the odd (even) fields corresponding to the same film frame are detected as being similar. In interlaced TV fields F 81  to F 90 , the data lines from the 1 data line to n data line and the data lines after s+2 data lines of each odd fields, and the data lines from the 2 data line to n+1 data line and data lines after the s+3 data lines all comply with the specific similarity pattern. Therefore, the present invention can generate corresponding data lines of the progressive frames P 81  to P 90  as mentioned above. However, because the data lines from the n+2 data line to the s+1 data line further comprises still texts, when comparing the data lines from the n+2 data line to the s+1 data line of the interlaced TV fields F 81  to F 90 , the present invention determines that the target data line of the field F 86  is not similar to the corresponding data line of the corresponding field F 88 . In other words, the similarity pattern of the data lines from the n+2 data line to the s+1 data line cannot be detected. As mentioned above, at this time, the present invention directly utilizes data near the data line to generate the two data lines of the progressive frame instead of utilizing successive data lines.  
         [0050]     In another embodiment, the similarity of data lines of successive odd and even fields is detect, and the progressive frames are generated according to the line-based similarity of corresponding fields. Please note that two odd and even fields originated from the same frames contains no exactly corresponding lines. Still, the line-based similarity can be determined in this embodiment. When the degree of similarity of two successive odd and even fields is larger than a predetermined value, the present invention can determine that the two fields come from the same source image. However, because the odd and even field respectively comprises odd data lines and even data lines, the odd and even fields have no directly corresponding data lines (i.e., the odd and even fields have no common data lines or common pixels). Therefore, the present invention cannot compare data lines of two odd fields or two even fields as mentioned above. In this embodiment, the present invention utilizes a zigzag detection to determine the similarity of two data lines of the two successive fields.  
         [0051]     Please refer to  FIG. 9 , which is a diagram of an interlaced field sequence according to the present invention. An odd field F 91 , an even field F 92 , an odd field F 93 , and an even field F 94  are orderly shown. In this embodiment, the gray value of each pixel of a target data line of a target field is compared with a corresponding pixel, which lies in a data line successive to the target data line, of the corresponding field; wherein the target field and the corresponding field are successive fields. Then, all of the comparison results of all pixels are summed to determine the similarity of the target data line of the target field. For example, now taking the k data line as a target data line, and the field F 91  as a target field. When the pixel  91 ( k,j ) is the target pixel, the pixel  92 ( k − 1 , j ) or the pixel  92 ( k + 1 , j ) are compared with the target pixel  91 ( k,j ). In the following disclosure,  91 ( k,j ),  92 ( k − 1 ,j), and  92 ( k + 1 , j ) are also utilized as the gray values of the pixels  91 ( k,j )  92 ( k − 1 , j ), and  92 ( k + 1 , j ). Please note that if the following equations are all satisfied, the present invention determines that the pixel  91 ( k, j ) is not smooth. 
 
Sign( 91 ( k,j )− 92 ( k − 1 , j )) XOR Sign( 92 ( k + 1 , j )− 91 ( k,j ))=1  equation(1) 
 
 Abs( 91 ( k,j )− 92 ( k − 1 , j ))&gt; K 3  equation(2) 
 
Abs( 92 ( k + 1 , j )− 91 ( k,j ))&gt; K 4  equation(3) 
 
         [0052]     In the above three equations, the values K3 and K4 are two predetermined values, and K3 and K4 can be the same value or different values.  
         [0053]     In this embodiment, when the two successive fields correspond to a motion (the two fields are different because of the motion), in the area, which have pixel value variance because of the motion, of the fields, the gray value of the middle pixel is the largest or the smallest. Equation (1) is satisfied. Furthermore, the gray value difference between the middle pixel and other vertically successive pixels is larger than a predetermined value. Equations (2) and (3) are satisfied. Therefore, the present invention determines that the three pixels are not changing smoothly. Moreover, if the number of pixels, which are determined as being not changing smoothly, of the target data line of the target field are larger than a predetermined value, the present invention determines that the two data lines (e.g., the target data line and the corresponding data line) are not similar. On the contrary, if the number of pixels, which are determined as being changing smoothly, of the target data line of the target field, the present invention determines that the two data lines (e.g., the target data line and the corresponding data line) are similar.  
         [0054]     Please refer to  FIG. 10 , which is a flow chart of detecting the similarity between an odd field and an even field. 
        Step  1000 : Set N as 0;     Step  1010 : If all pixels of the target data line of the target field are all detected, step  1015  is performed; otherwise, step  1020  is performed;     Step  1015 : Determine that the target data line and two data lines of the corresponding field are similar, and then step  1070  is performed;     Step  1020 : Utilize a undetected pixel of the target data line of the target field as the target pixel, respectively utilize an upper data line and a lower data line of the corresponding field as two corresponding data lines, and utilize two pixels having the same horizontal coordinate of the target pixel as a first successive pixel and a second successive pixel;     Step  1030 : If the gray value Uj of the first successive pixel is larger than the gray value Mj, the gray value difference between the gray value Uj and the gray value Mj is larger than a third predetermined value K3, or the gray value Dj of the second successive pixel is larger than the gray value Mj and the gray value difference between the gray value Dj and the gray value Mj is larger than a fourth predetermined value K4, step  1040  is performed; otherwise, step  1010  is performed;     Step  1040 : Add 1 to N;        
 
         [0061]     Step  1050 : If N is larger than a fifth predetermined value K5, step  1060  is performed; if N is less than the predetermined value K3, step  1010  is performed; 
        Step  1060 : Determine that the target data line and the two corresponding data lines are similar;     Step  1070 : Finish.        
 
         [0064]     In order to detect the similarities of the data lines of two successive odd and even fields, the image processing apparatus can be achieved by software or hardware circuits.  
         [0065]     Please refer to  FIG. 11 , which is a circuit diagram of a field similarity detection device  1100  according to the present invention. The field similarity detection device  1100  comprises a pixel comparator  1110 , an accumulator  1180 , and a similarity determiner  1190 . The pixel comparator  1110  compares each pixel of the target data line of the target field with two corresponding pixels of two corresponding data lines of the corresponding field to determine the similarities. In this embodiment, the field similarity detection device  1100  detects similarities of data lines of the odd and even fields. For example, when the target pixel is the m pixel of the n data line of the target field, two successive pixels can be the m pixel of the n+1 data line of the target field and the m pixel of the n−1 data line of the target pixel. The pixel comparator  1110  comprises two pixel processing modules  1120  and  1130  for calculating the gray value differences between the target pixel and two successive pixels and obtaining related information. The pixel processing module  1120  and  1130  respectively comprises a subtraction units  1122  and  1132  for calculating the gray value differences between the gray value of the target pixel and gray values of the two successive pixels. The subtraction units  1122  and  1132  respectively comprises absolute value units  1126  and  1136  for outputting the absolute values of the gray value differences, and positive/negative sign units  1124  and  1134  for outputting the sign information of the gray value. The pixel comparator  1110  further comprises a XOR gate  1140 , two comparing units  1150  and  1160 , and an AND gate  1170 . The XOR gate  1140 , coupled to the comparing units  1124  and  1134  of the two pixel processing modules  1120  and  1130 , is utilized for calculating an XOR result of the sign information of the two gray value differences outputted by the two pixel processing modules  1120  and  1130 . When one of the two gray value differences is positive and the other is negative, the XOR gate  1140  outputs the value 1. The comparing units  1150  and  1160 , respectively coupled to the absolute value units  1126  and  1136  of the two pixel processing modules  1120  and  1130 , are utilized for comparing the gray values differences between the gray value of the target pixel and the gray values of the two successive pixels with a predetermined value. In addition, if the gray value differences are respectively larger than predetermined values K3 and K4, the comparing units  1150  and  1160  output the value 1. On the other hand, if the gray value differences are respectively less than predetermined values K3 and K4, the comparing units  1150  and  1160  output the value 0. The AND gate  1170 , coupled to the output ends of the two comparing units  1150  and  1160  and the output end of the XOR gate  1140 , is utilized for performing a calculation on the three outputs. The accumulator  1180 , coupled to the output end of the AND gate  1170 , comprises an adder  1182  and a buffer  1184 . The accumulator is utilized for performing an accumulating calculation on the output of the AND gate  1170 . In this embodiment, if the gray value differences are both larger than the predetermined values and the gray value of the target pixel is the largest or the least among the three pixels, the pixel comparator  1110  outputs the value 1 to the accumulator  1180 . This represents that the gray value of the target pixel is not changing smoothly. It is also called as a zigzag. Otherwise, the pixel comparator  1110  outputs the value 0 to the accumulator  1180 . Therefore, if each pixel of the target data line of the target field is set as the target pixel, and each pixel is compared with its corresponding pixel, the pixel comparator  1110  outputs the value 1 or 0 to the accumulator  1180  according to the condition of each pixel. The similarity determiner  1190 , coupled to the output end of the accumulator  1180 , is utilized for determining that the target data line of the target field is not similar to the two corresponding data lines of the corresponding field if the accumulating result of the accumulator  1180  is larger than the predetermined number K5.  
         [0066]      FIG. 12  shows interlaced TV fields F 121 -F 128  generated from TV frames instead of film frames. Furthermore, some of the TV fields F 121 -F 128  comprise running texts. As shown in  FIG. 12 , the field F 121 , F 123 , F 125 , and F 127  are odd fields, and the field F 122 , F 124 , F 126 , and F 128  are even fields. In this embodiment, the running text is added between the n+2 data line and the s+1 data line. Similarly, the range of the running text is shifted in one data line in the odd and even fields. It is well known that the gray values of pixels of the even and odd fields, which correspond to the same frame, changes smoothly as long as they comprises no running text. For example, the data line  121 ( g ) of the field F 121  is similar to the data line  122 ( g − 1 ) and the data line  122 ( g + 1 ). However, the data line  122 ( g + 1 ) is not similar to the data line  123 ( g ) and  123 ( g + 2 ). In other words, if the similarities of data lines of a plurality of two successive fields are similar in interval for a predetermined number of times, then the present invention determines that the data lines are generated from a TV frame instead of the film frames. Therefore, the odd and even fields, which correspond to the same frame, can be combined to generate the progressive TV frame. As shown in  FIG. 12 , the data lines above the n+1 data line and below the s+2 data line of progressive frames P 121 -P 128  are generated by combining two corresponding fields. For example, the first data line of the field F 121  and the second data line of the field F 122  are combined to generate the first and the second data lines of the progressive frames P 121  and P 122 . However, when the added running text breaks the original similarity of data lines (e.g., the embodiments shown in  FIG. 4  and  FIG. 8 ), the present invention directly utilizes the data lines of the current field to generate corresponding data lines of the progressive frames.  
         [0067]     As mentioned above, if the TV service provider adds the running text, the present invention can utilize data lines as a unit to determine the similarity of the fields. Therefore, the present invention can prevent poor display quality due to the running texts for appearing. Furthermore, the present invention can still perform the interpolation on most of pixels of the TV fields and perform the de-interlacing operation on most of the data lines of the TV fields to compensate the TV display quality. The present invention does not perform any operation on the data lines comprising the running text. This causes the running text to appear as clear rather than blurry. For example, N*1-bit line buffer can be added to a display controller. The line buffer can continuously records the similarities of all data lines of the target field. Therefore, the display controller can selectively perform the de-interlacing operation or the interpolation operation on the pixels according to the data stored in the line buffer. This allows the present invention to avoid the processing of the data lines comprising running texts. Please note that the value N is related to the display quality of the TV frame. For example, in the NTSC system, it comprises 525 data lines; the value N can be 525. In the PAL system, it comprises 625 data lines; the value N can be 625. Please note that the added hardware is limited so that the hardware cost is minimal. Moreover, because the running text is not disposed in the central position of the frames viewers may not observe the running text as much as more centrally located images. The present invention can utilize N*1-bit line buffer to utilize the data lines as a unit to determine the similarities of fields. Until the current image source does not comply with a predetermined similarity pattern, the present invention maintains the current playing mode (e.g., the film mode). Please note that the present invention device, which utilizes the data line as a unit to determine the field similarities, can operate independently or it can operate with other prior art devices that utilize entire fields to determine the field similarities.  
         [0068]     Please refer to  FIG. 13 , which is a diagram of a display controller of an embodiment according to the present invention. The display controller comprises a buffer  1310 , a de-interlacer  1320 , a scaler  1330 , a data line similarity detector  1340 , a data line state recorder  1350 , and a field state flag  1360 . The buffer  1310  receives the incoming field data and stores a plurality of data lines in a plurality of inner line buffers. The de-interlacer  1320 , coupled to the buffer  1310 , generates a de-interlacing output. The scaler  1330 , coupled to the de-interlacer  1320 , generates a scaling output. The data line similarity detector  1340 , coupled to the buffer  1310 , detects the similarities of all data lines of the field and storing the similarities in the data line state recorder  1350 . Preferably, the data line state recorder  1350  contains an N*1 line buffer, as mentioned above, wherein N associates with the display resolution (e.g., N is 525 in the NTSC system or N is 625 in the PAL system). Additionally, the data line similarity detector  1340  determines the field state of the target field and stores the state in the field state flag  1360 . The field state flag  1360  comprises three flag bits, which respectively represents three states of the running text, the still text, and the bad editing. These flag bits can be referenced by the de-interlacer  1320 . Alternatively, if the data line similarity detector  1340  also determines the correct mode (e.g., film mode or TV mode) of the target field, the data line state recorder  1350  can be 525*5 bits in the NTSC system for storing the similarities of 525 data lines at five successive time points. Please note that data line state recorder  1350  can be 625*5 bits in the PAL system. Therefore, the de-interlacer  1320  can selectively de-interlace the data according to the data line state recorder  1350 . Then the scaler  1330  can perform a scaling operation on the processed data. These operations still stays the correct mode although the running text distroys the original display structure of the pixels. For example, the target field comprises a main image area without running text, and a secondary image area with, for example, the running text. For example, if the running text lies in the lower position of the frame, the de-interlacer  1320  and the scaler  1330  can perform the de-interlacing and scaling operation on the main area of the target field and the successive field according to the data line state recorder  1350 . If the target field is an odd field, then the successive field is an even field. Alternatively, if the target field is an even field, then the successive field is an even field. The secondary area is not interlaced with an adjacent field because that will make it worse. Preferably, the target field is interpolated and scaled by itself.  
         [0069]     Please refer to  FIG. 14 , which is a flow chart of selectively performing the de-interlacing operation and the scaling operation according to detected similarities. The flow is illustrated as follows. 
        Step  1400 : Start;     Step  1410 : Analyze the similarities of the data lines of the target field and record the similarities in the N*1-bit data line state recorder;     Step  1420 : De-interlace and scale the main area of the target field with a successive field, which is the area having no running text, according to the similarities stored in the data line state recorder;     Step  1430 : De-interlace and scale the secondary areas of the target field without referring to other fields. This allows the running text clearer;     Step  1440 : Finish.        
 
         [0075]     In summary, the present invention provides a method of utilizing a data line as a unit to generate progressive TV frames according to interlaced TV fields and apparatus thereof. The present invention can more elastically generate the progressive TV frames. Even when a running text is added to the field, the present invention can process other areas that do not contain any running texts. In addition, the present invention can prevent poor editing of the fields due to the interlaced TV fields being derived from film data.  
         [0076]     The present invention can first utilize a whole field as a unit to detect whether the similarity pattern exist in order to ensure what the data source of the interlaced TV fields is. And then the present invention utilizes the data line as a unit to detect the similarity so that the present invention can generate a high-quality progressive TV frames. Furthermore, the present invention can detect whether the similarity complies with a predetermined similarity pattern. If the number of the similarities of the data lines of the target field is larger than a predetermined number, the present invention directly utilizes the target field to generate the progressive TV frames.  
         [0077]     The present invention also provides a data line similarity detecting device and related methods thereof. The present invention can utilize two fields, which have one field between them, or two successive fields to perform the similarity detection. Of course, the present invention also utilizes one data line as a unit. The present invention similarity detecting device comprises a pixel comparator for comparing the gray values between the target pixel and a corresponding pixel; an accumulator, coupled to the pixel comparator, for accumulating the comparison results outputted by the pixel comparator; and a similarity determiner, coupled to the accumulator, for determining the similarity of the data lines of the target field.  
         [0078]     Please note that the present invention data line similarity detecting device shown in  FIG. 7  and  FIG. 11  is only utilized as an preferred embodiment, not a limitation. In other words, any other usable hardware circuits or software method having this function all obey the spirit of the present invention.  
         [0079]     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.