Abstract:
A semiconductor package includes at least one semiconductor constructing body which has a semiconductor substrate and a plurality of external connection electrodes formed thereon. An insulating film covers the semiconductor constructing body. Each of interconnections which has a projecting electrode is formed on the insulating film. The projecting electrodes of the interconnection cut through the insulating film at portions corresponding to the external connection electrodes and electrically connected to the external connection electrodes.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     The present application is a Divisional Application of U.S. application Ser. No. 10/186,530, filed Jul. 1, 2002, which is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2001-202518, filed Jul. 3, 2001, the entire contents of which are incorporated herein by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a digital camera that can enlarge an image and an image processing method for enlarging an image.  
         [0004]     2. Description of the Related Art  
         [0005]     Recently, the development of personal computers has contributed to the wide spread of digital still cameras that record digital image data obtained using an image pick-up element, in a memory card in place of a silver film.  
         [0006]      FIG. 1  shows the configuration of a circuit in a digital still camera of this kind. When one image is picked up (single image pick-up), the illustrated circuit basically compresses YUV data (luminance and color difference data) before expanding one frame of the YUV data on a buffer memory.  
         [0007]     An optical image obtained using an optical system  11  is formed as an image on a CCD  12  used as an image pick-up element. The CCD  12  includes, for example, an RGB color filter of Bayer type. Color image data obtained (hereinafter referred to as “Bayer data”) is sequentially sampled and held by a sample and hold circuit (S/H)  13 , subsequently digitized by an A/D converter  14 , and then supplied to a line processing unit  15 .  
         [0008]     The line processing unit  15  integrates the sequentially transmitted Bayer data into line data. A first transfer unit  16  transfers the Bayer data, integrated into the line data, to a memory  17 , where the data is expanded and stored.  
         [0009]     Once a predetermined number of lines of Bayer data are expanded on the memory  17 , these data are read in block units and transferred to a Bayer/YUV converting unit  19  by a second transfer unit  18 A.  
         [0010]     The Bayer/YUV converting unit  19  executes an interpolating process or a color space process to convert the Bayer data (RGB data) into the YUV data, luminance and color difference color image. Then, the data thus obtained are supplied to a JPEG processing unit  21  via a switch (SW)  20 . On the other hand, a third transfer unit  23  transfers these data to the memory  7  via a switch  22 . Then, the data is expanded and stored in the memory  7 .  
         [0011]     The YUV data stored in the memory  17  are transferred to a display control unit  25  by a fourth transfer unit  24 . Then, the display control unit  25  generates and outputs an analog video output signal and a signal for display on a liquid crystal monitor.  
         [0012]     The JPEG processing unit  21  executes a data compression process such as an ADCT (Adaptive Discrete Cosine Transform) process or Huffman encoding process to the YUV data transferred by the Bayer/YUV converting unit  19  via the switch  20 . Thus, JPEG data of a drastically reduced amount is obtained. A fifth transfer unit  26  transfers the JPEG data thus obtained to the memory  17 , where the data is expanded and stored.  
         [0013]     The JPEG data expanded and stored in the memory  17  is recorded in a memory card as a storage medium.  
         [0014]     On the other hand, in a reproduction mode, JPEG data read from the memory card is stored in the memory  17  and then read and transferred to the JPEG processing unit  21  by a sixth transfer unit  27 . Then, the JPEG processing unit  21  converts the JPEG data to the original YUV data, and the third transfer unit  23  transfers this YUV data via the switch  22  to the memory  17  for storage. Subsequently, the data is delivered to the display control unit  25  by the fourth transfer unit  24 .  
         [0015]     The above described circuit operations are totally controlled by a system controller  28  including a CPU. The operation of the system controller  28  is controlled in response to key operation signals input from a key input unit  29  including a shutter key and a mode key.  
         [0016]     Now, a specific process for generating the YUV data will be described in detail.  
         [0017]     Bayer data obtained by the line processing unit  15  and expanded and stored in the memory  17  is illustrated in  FIG. 2A .  
         [0018]     If it is assumed that it is necessary to refer a pixel configuration of 5×5 pixels of the Bayer data ( FIG. 2A ) as shown in  FIG. 2B  in order to generate one pixel of the YUV data by the Bayer/YUV converting unit  19 , the YUV data as shown in  FIG. 2C  is generated.  
         [0019]     It is assumed that the YUV data generated is transferred and output in the order shown in  FIG. 3  and comprises blocks each having a vertical size of four pixels. Then, the pixels of the original Bayer data are read in the order as shown in  FIG. 4 . That is, for the first block with the range of lines C 1  to C 8 , the pixels are read in the following order:  
         [0020]     (C 1 ,  1 )→(C 1 ,  2 )→(C 1 ,  3 )→(C 1 ,  4 )→(C 1 ,  5 )→(C 1 ,  6 )→(C 1 ,  7 )→(C 1 ,  8 )→(C 2 ,  1 )→(C 2 ,  2 )→ . . .  
         [0021]     For the second block the starting line of which is shifted downward by four lines and which has the range of lines C 5  to C 12 :  
         [0022]     (C 1 ,  5 )→(C 1 ,  6 )→(C 1 ,  7 )→(C 1 ,  8 )→(Cl,  9 )→(C 1 ,  10 )→(C 1 ,  11 )→(C 1 ,  12 )→(C 2 ,  5 )→(C 2 ,  6 )→ . . .  
         [0023]     Compared to the Bayer data read in this pixel position order, the pixels of the YUV data is transferred in the following order. For the first block:  
         [0024]     (C 3 ,  3 )→(C 3 ,  4 )→(C 3 ,  5 )→(C 3 ,  6 )→(C 4 ,  3 )→(C 4 ,  4 )→(C 4 ,  5 )→(C 4 ,  6 )→(CS,  3 )→(CS,  4 )→ . . .  
         [0025]     For the second block:  
         [0026]     (C 3 ,  7 )→(C 3 ,  8 )→(C 3 ,  9 )→(C 3 ,  10 )→(C 4 ,  7 )→(C 4 ,  8 )→(C 4 ,  9 )→(C 4 ,  10 )→(CS,  7 )→(C 5 ,  8 )→ . . .  
         [0027]      FIG. 5A  shows the configuration of pixels obtained when the YUV data is generated from Bayer data as described above. In the Bayer data in  FIG. 5A , the hatched pixel shows a pixel used in generating the YUV data but which does not directly generate the corresponding YUV data.  
         [0028]     In a Bayer data block read from the memory  17  and comprising eight lines, upper four lines are also read in the upper adjacent block. Thus, the YUV data generated in correspondence with these lines is configured not to contain any duplicate lines.  
         [0029]      FIG. 5B  illustrates the relationship between a Bayer data block read from a Bayer data frame and a YUV data block generated from the Bayer data block.  
         [0030]     As described above, when the YUV data is generated from the Bayer data, the minimum required YUV data is generated, as shown in  FIG. 5A .  
         [0031]     Accordingly, the vertical size of the YUV data block is set at 8 if the required data is 4:2:2 (Y:Cb:Cr), and is set at 16 if the required data is 4:2:0. Then, the JPEG processing unit  21 , which subsequently compresses the data, executes the process on every block comprising 8×8 pixels. Consequently, the YUV data can be transferred directly to the JPEG processing unit  21 .  
         [0032]     Here, with the circuit configuration shown in  FIG. 1 , in order to increase the speed of an electronic zooming process (enlarging process) in which the image data obtained through image pick-up is interpolated to increase the number of pixels constituting the image, it is assumed that a circuit that executes a pixel number conversion using hardware is provided succeeding to the Bayer/YUV converting unit  19 , for example, between the switch  22  and the third transfer unit  23 , instead of executing the enlarging process after expanding and storing one frame of YUV data on the memory  17 . On these assumptions, since only the minimum required YUV data is transferred as described above, the interpolating process fails to generate pixels located between the pixels on the lowermost line of a YUV data block and the pixels on the uppermost line of the next YUV data block.  
         [0033]     Thus, on the assumption that the same pixels as those on the lowermost line of the YUV data block are added as a line immediately below the lowermost line or that the pixels on lowermost line of the YUV data block are overlapped with the line immediately below the lowermost line, the pixel number converting circuit must execute an interpolating process (enlarging process) using these duplicate pixels. As a result, disadvantageously, the image is more markedly degraded as the enlargement ratio for electronic zooming increases in the vertical direction.  
         [0034]     Further, it is assumed that the pixel number converting circuit executes an electronic zooming process (enlarging process) on each YUV data block. Then, since each YUV data block contains the same number of lines, it contains the same number of lines even after the enlarging process (interpolating process). Thus, disadvantageously, the available enlargement ratio (enlargement ratio) is limited.  
         [0035]     Furthermore, if the pixel number converting circuit is to execute an electronic zooming process (enlarging process) on YUV data blocks and the YUV data block generated by the Bayer/YUV converting process is transferred directly to the JPEG processing unit  21 , the YUV data, which has not undergone any electronic zooming process, is compressed and stored in the memory card. To avoid this, it is necessary to store the YUV data already subjected to an electronic zooming process in the memory  17  and transferring the read data to the JPEG processing unit  21 . Consequently, much time is required to record the image.  
       BRIEF SUMMARY OF THE INVENTION  
       [0036]     The present invention is directed to method and apparatus that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.  
         [0037]     According to an embodiment of the present invention, a digital camera comprises:  
         [0038]     an image pick-up unit that picks up an image of an object and outputs image data;  
         [0039]     a transfer unit that transfers the image data output from the image pick-up unit in units of a predetermined number of lines, with at least one line overlapping at least one line of an immediately following unit; and  
         [0040]     an enlarging process unit that enlarges the image data transferred from the transfer unit in units of the predetermined number of lines.  
         [0041]     Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter. 
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING  
       [0042]     The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present invention and, together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the present invention in which:  
         [0043]      FIG. 1  is a block diagram showing the configuration of a circuit in a conventional digital still camera;  
         [0044]      FIGS. 2A, 2B , and  2 C are diagrams showing the concept of generating the YUV data from the Bayer data;  
         [0045]      FIG. 3  is a diagram showing the concept of generating the YUV data from the Bayer data;  
         [0046]      FIG. 4  is a diagram showing the concept of generating the YUV data from the Bayer data;  
         [0047]      FIGS. 5A and 5B  are diagrams showing the concept of generating the YUV data from the Bayer data;  
         [0048]      FIG. 6  is a block diagram showing the configuration of a circuit in a digital still camera according to the first embodiment of the present invention;  
         [0049]      FIG. 7  is a flow chart showing the contents of a process executed depending on whether or not an electronic zooming function is to be executed in a pick-up mode, according to the first embodiment;  
         [0050]      FIG. 8  is a diagram showing a relationship between a Bayer data transfer state and the YUV data correspondingly generated;  
         [0051]      FIG. 9  is a diagram showing a different relationship between the Bayer data transfer state and the YUV data correspondingly generated;  
         [0052]      FIG. 10  is a block diagram showing the configuration of a circuit in a digital still camera according to the second embodiment of the present invention;  
         [0053]      FIG. 11  is a flow chart showing the contents of a process executed depending on whether or not the electronic zooming function is executed in the pick-up mode, according to the second embodiment;  
         [0054]      FIG. 12  is a block diagram showing the configuration of a circuit in a digital still camera according to the third embodiment of the present invention;  
         [0055]      FIG. 13  is a diagram showing specific correspondences between pixels in an enlarging process according to the third embodiment;  
         [0056]      FIG. 14  is a block diagram showing the configuration of a circuit that extracts pixels according to the third embodiment;  
         [0057]      FIG. 15  is a diagram illustrating an output form of line number data according to the third embodiment; and  
         [0058]      FIG. 16  is a diagram illustrating another output form of line number data according to the third embodiment. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0059]     An embodiment of a digital still camera according to the present invention will now be described with reference to the accompanying drawings.  
       First Embodiment  
       [0060]      FIG. 6  is a block diagram showing the configuration of the first embodiment. The same portions as those shown in  FIG. 1  will be indicated in the same reference numerals and their detailed description will be omitted.  
         [0061]     As shown in  FIG. 2B , it is assumed that 5×5 pixels of Bayer data are required to generate one pixel of YUV data and a YUV data block generated from the Bayer data requires a vertical size of at least four pixels. In this case, the second transfer unit  18  for reading the Bayer data stored in the memory  17  reads the Bayer data in units of nine lines, while the data being shifted by four lines.  
         [0062]     The circuit has a pixel number converting unit (enlarging process unit)  31  connected between the switch  22  that opens and closes a transfer path for YUV data blocks sequentially generated by the Bayer/YUV converting unit  19  and the third transfer unit  23  that expands and stores the YUV data blocks sequentially transferred via the switch  22 , in the memory  17 .  
         [0063]     When an electronic zooming function is turned on, the pixel number converting unit  31  enlarges the sequentially input YUV data blocks, thereby increasing the number of pixels in the block according to an enlargement ratio.  
         [0064]     Now, the operation of this embodiment will be described.  
         [0065]      FIG. 7  shows the contents of a process executed depending on whether or not an electronic zooming operation is to be executed in a pick-up mode. First, it is determined whether or not an electronic zooming function is turned on using a zoom key included in the key input unit  29  (step A 01 ).  
         [0066]     If the electronic zooming function has not been turned on, the second transfer unit  18  reads the Bayer data in units of one block comprising eight lines from the memory  17  such that the upper four lines of the data block are overlapped by lower four lines of the upper adjacent data block, as shown in  FIG. 5A . The second transfer unit  18  then transfers this block to the Bayer/YUV converting unit  19 .  
         [0067]     Thus, YUV data blocks sequentially generated by the Bayer/YUV converting unit  19  on the basis of the Bayer data contain no duplicate pixels. The YUV data blocks sequentially generated pass through the pixel number converting unit  31  via the switch  22  to reach the third transfer unit  23 . The third transfer unit  23  transfers the data blocks to the memory  17 , where the data blocks are expanded and stored. The fourth transfer unit  24  then transfers the data blocks to the display control unit  25 . A liquid crystal monitor of this digital still camera displays and outputs the data blocks (step A 03 ).  
         [0068]     If it is determined at step A 01  that the electronic zooming function is turned on, the second transfer unit  18  reads the Bayer data in units of one block comprising nine lines from the memory  17  as shown in  FIG. 8 . The second transfer unit  18  then transfers this block to the Bayer/YUV converting unit  19 .  
         [0069]     For example, the pixels of the Bayer data are read by the second transfer unit  18  in the following order. For the first block with the range of lines C 1  to C 9  shown in  FIG. 4 :  
         [0070]     (C 1 ,  1 )→(C 1 ,  2 )→(C 1 ,  3 )→(C 1 ,  4 )→(C 1 ,  5 )→(C 1 ,  6 )→(C 1 ,  7 )→(C 1 ,  8 )→(C 1 ,  9 )→(C 2 ,  1 )→(C 2 ,  2 )→ . . .  
         [0071]     For the second block the starting line of which is shifted downward by four lines and which has the range of lines C 5  to C 13 :  
         [0072]     (C 1 ,  5 )→(C 1 ,  6 )→(C 1 ,  7 )→(C 1 ,  8 )→(C 1 ,  9 )→(C 1 ,  10 )→(C 1 ,  11 )→(C 1 ,  12 )→(C 1 ,  13 )→(C 2 ,  5 )→(C 2 ,  6 )→ . . .  
         [0073]     Accordingly, the Bayer/YUV converting unit  19  generates five lines of YUV data from nine lines of Bayer data. For example, the pixels of YUV data generated are transferred in the following order. For the first block:  
         [0074]     (C 3 ,  3 )→(C 3 ,  4 )→(C 3 ,  5 )→(C 3 ,  6 )→(C 3 ,  7 )→(C 4 ,  3 )→(C 4 ,  4 )→(C 4 ,  5 )→(C 4 ,  6 )→(C 4 ,  7 )→(C 5 ,  3 )→(CS,  4 )→ . . .  
         [0075]     For the second block:  
         [0076]     (C 3 ,  7 )→(C 3 ,  8 )→(C 3 ,  9 )→(C 3 ,  10 )→(C 3 ,  11 )→(C 4 ,  7 )→(C 4 ,  8 )→(C 4 ,  9 )→(C 4 ,  10 )→(C 4 ,  11 )→(C 5 ,  7 )→(CS,  8 )→ . . .  
         [0077]     In this manner, the YUV data in the block located at a certain position is generated so that the lowermost line of the data is overlapped with (is the same as) the uppermost line of the YUV data in the next block, as shown by the hatching in  FIG. 8 .  
         [0078]     On the YUV data block generated so as to contain one duplicate line, the pixel number converting unit  31  executes, via the switch  22 , a pixel converting process including an image enlarging process corresponding to the enlargement ratio. During this enlarging process, the YUV data block is intentionally transferred so as to partially overlap the following data block as described above. Consequently, when pixels lying between blocks are generated, an image to be generated is not degraded.  
         [0079]     Specifically, the enlarging process comprises referencing 2×2 pixels of the YUV data to generate pixel data to be located in the center of these pixels, by interpolation. Since a duplicate line is added to the YUV data block as the fifth line, pixel data for an interpolating line between the fourth line of this data block and the first line of the next data block can be generated by using the YUV data in the fourth and fifth lines and referencing an area of 2×2 pixels in each of these lines when the fourth line of the YUV data is to be processed.  
         [0080]     Then, the third transfer unit  23  transfers the YUV data blocks sequentially obtained through the enlarging process and each having an increased number of lines, to the memory  17 , where the data blocks are expanded and stored. The fourth transfer unit  24  then transfers each YUV data block to the display control unit  25 . The liquid crystal monitor of this digital still camera displays and outputs a required display range (step A 02 ).  
         [0081]     In this case, the YUV data in the fifth line of the block is only used by the pixel number converting unit  31  to execute an enlarging process for electronic zooming. The third transfer unit  23  does not transfer the YUV data in this fifth line to the memory  17 .  
         [0082]     The monitor display process is thus executed at step A 02  or A 03  depending on whether or not the electronic zooming function is turned on. Then, while repeatedly executing a process of determining whether or not the shutter key included in the key input unit  29  is operated (step A 04 ) and if not, returning to the process starting with step A 01 , the apparatus waits for the shutter key to be operated.  
         [0083]     If it is determined at step A 04  that the shutter key is operated, then it is determined whether or not the electronic zooming function is turned on (step A 05 ).  
         [0084]     If the electronic zooming function has not been turned on, a normal image recording process is executed. That is, the Bayer data obtained through an image pick-up operation performed by the CCD  12  at a next timing will be transmitted to the first transfer unit  16  via the sample and hold circuit  13 , A/D converter  14 , and line processing unit  15 . The first transfer unit  16  then transfers the Bayer data to the memory  17  for storage. Then, the second transfer unit  18  reads every block of the Bayer data comprising eight lines from the memory  17 . Subsequently, the Bayer/YUV converting unit  19  generates the YUV data blocks each comprising four lines and having no duplicates as shown in  FIGS. 5A and 5B .  
         [0085]     The YUV data blocks sequentially generated by the Bayer/YUV converting unit  19  and each comprising four lines are sequentially transferred to the JPEG processing unit  21  via the switch  20 . Each of the data blocks is then compressed to obtain the JPEG data in units of block. The fifth transfer unit  26  then transfers one frame of JPEG data to the memory  17  for storage and then records these data in a memory card (step A 07 ).  
         [0086]     Once the normal image recording process is executed, the process returns to step A 01  to provide for the next pick-up session.  
         [0087]     If it is determined at step A 05  that the electronic zooming function is turned on when the shutter key is operated, then an image recording process including an image enlarging process is executed. The Bayer data obtained through an image pick-up operation performed by the CCD  12  at a next timing will be transmitted to the first transfer unit  16  via the sample and hold circuit  13 , A/D converter  14 , and line processing unit  15 . The first transfer unit  16  then transfers the Bayer data to the memory  17  for storage. Then, the second transfer unit  18  reads every block of the Bayer data comprising nine lines from the memory  17 . Subsequently, the Bayer/YUV converting unit  19  generates the YUV data blocks each comprising five lines including one duplicate line as shown in  FIG. 8 .  
         [0088]     The YUV data blocks generated by the Bayer/YUV converting unit  19  and each comprising five lines are sequentially transferred to the pixel number converting unit  31  via the switch  22 . The pixel number converting unit  31  then enlarges the data block so as to increase the number of pixels according to the currently set enlargement ratio. Subsequently, the third transfer unit  23  transfers the obtained YUV data block to the memory  17  for storage.  
         [0089]     Specifically, this enlarging process comprises referencing 2×2 pixels of the YUV data to generate pixel data to be located in the center of these pixels, by interpolation, as described above. Since a duplicate line is added to the YUV data block as the fifth line, pixel data for an interpolating line between the fourth line of this data block and the first line of the next data block can be generated by using the YUV data in the fourth and fifth lines and referencing an area of 2×2 pixels in each of these lines when the fourth line of the YUV data is to be processed.  
         [0090]     Subsequently, the sixth transfer unit  26  transfers the YUV data enlarged and stored in the memory  17  to the JPEG processing unit  21 . The JPEG processing unit  21  then compresses the data to obtain JPEG data. The fifth transfer unit  26  then transfers the JPEG data to the memory  17  for storage and then records these data in the memory card (step A 06 ).  
         [0091]     Once the image recording process including the image enlarging process is executed, the process returns to step A 01  to provide for the next pick-up session.  
         [0092]     In the above embodiment, it is assumed that 5×5 pixels including two pixels (n=2) on each side of the target pixel are required for reference, and the YUV data is formed such that blocks each containing one duplicate line (m=1) as shown in  FIG. 8 . However, the present invention is not limited to this example. The second transfer unit  18  may sequentially transfer the Bayer data in units of (4n+m) (m and n are natural numbers) lines to the Bayer/YUV converting unit  19 , while the data being shifted by 2n lines. Then, the Bayer/YUV converting unit  19  generates YUV data formed of blocks each formed of (2n+m) lines based on (2n+1) pixels on each side of the target pixel. The variables m and n can be arbitrarily set within the range of natural numbers.  
         [0093]     For example, if n=m=2, then each block read from the memory  17  and transferred to the Bayer/YUV converting unit  19  by the second transfer unit  18  comprises 10 (=4×2+2) lines, and the starting line of each block is shifted by four (=2×2) lines. Correspondingly, the Bayer/YUV converting unit  19  sequentially generates the YUV data comprising 6 (=2×2+2) lines including two duplicate lines.  
         [0094]     In this case, the pixels of the Bayer data are read by the second transfer unit  18  in the following order. For the first block with the range of lines C 1  to C 10  shown in  FIG. 9 :  
         [0095]     (C 1 ,  1 )→(C 1 ,  2 )→(C 1 ,  3 )→(C 1 ,  4 )→(C 1 ,  5 )→(C 1 ,  6 )→(C 1 ,  7 )→(C 1 ,  8 )→(C 1 ,  9 )→(C 1 ,  10 )→(C 2 ,  1 )→(C 2 ,  2 )→ . . .  
         [0096]     For the second block the starting line of which is shifted downward by four lines and which has the range of lines C 5  to C 14 :  
         [0097]     (C,  5 )→(C 1 ,  6 )→(C 1 ,  7 )→(C 1 ,  8 )→(C 1 ,  9 )→(C 1 ,  10 )→(C 1 ,  11 )→(C 1 ,  12 )→(C,  13 )→(C,  14 )→(C 2 ,  5 )→(C 2 ,  6 )→ . . .  
         [0098]     Accordingly, the Bayer/YUV converting unit  19  generates six lines of YUV data from these ten lines of Bayer data. For example, the pixels of the generated YUV data are transferred in the following order. For the first block:  
         [0099]     (C 3 ,  3 )→(C 3 ,  4 )→(C 3 ,  5 )→(C 3 ,  6 )→(C 3 ,  7 )→(C 3 ,  8 )→(C 4 ,  3 )→(C 4 ,  4 )→(C 4 ,  5 )→(C 4 ,  6 )→(C 4 ,  7 )→(C 5 ,  3 )→(C 5 ,  4 )→ . . .  
         [0100]     For the second block:  
         [0101]     (C 3 ,  7 )→(C 3 ,  8 )→(C 3 ,  9 )→(C 3 ,  10 )→(C 3 ,  11 )→(C 3 ,  12 )→(C 4 ,  7 )→(C 4 ,  8 )→(C 4 ,  9 )→(C 4 ,  10 )→(C 4 ,  11 )→(C 5 ,  7 )→(C 5 ,  8 )→ . . .  
         [0102]     In this manner, the YUV data in the block located at a certain position are generated so that the lower two lines of the data are overlapped with the upper two lines of the YUV data in the next block, as shown by the hatching in  FIG. 9 .  
         [0103]     In this case, a specific process executed by the pixel number converting unit  31  comprises referencing 4×4 pixels of the YUV data to generate pixel data to be located in the center of these pixels, by interpolation. Since two duplicate lines are added to the YUV data block as the fifth and sixth lines, pixel data for an interpolating line between the fourth line of this data block and the first line of the next data block can be generated by using the YUV data in the third to sixth lines (four lines) and referencing an area of 4×4 pixels in each of these lines when the fourth line of the YUV data is to be processed.  
         [0104]     As described above, according to this embodiment, the second transfer unit  18  transfers the Bayer data to allow the Bayer/YUV converting unit  19  to generate the YUV data blocks each having m duplicate lines so that the image is not degraded when the pixel number converting unit  31  executes an enlarging process for electronic zooming. Therefore, the image is prevented from being degraded during electronic zooming without using any complicated circuit configuration.  
         [0105]     In the first embodiment, only color image data is processed. However, monochromic image data can be similarly and easily processed by executing a similar process while noting only Y, a luminance component of YUV data.  
         [0106]     Other embodiments of the digital still camera according to the present invention will be described. The same portions as those of the first embodiment will be indicated in the same reference numerals and their detailed description will be omitted.  
       Second Embodiment  
       [0107]     A digital still camera according to the second embodiment of the present invention will be described below with reference to the drawings.  
         [0108]      FIG. 10  shows the configuration of a circuit in the camera, and is essentially similar to that shown in  FIG. 6 .  
         [0109]     The pixel number converting unit  31  is placed immediately succeeding to the Bayer/YUV converting unit  19 . The Bayer/YUV converting unit  19  supplies its outputs to the JPEG processing unit  21  and third transfer unit  23  via the switches  20  and  22 .  
         [0110]     Next, the operation of this embodiment will be described.  
         [0111]      FIG. 11  shows the contents of a process executed depending on whether or not an electronic zooming operation is to be executed in the pick-up mode. First, it is determined whether or not the electronic zooming function is turned on using the zoom key included in the key input unit  29  (step B 01 ).  
         [0112]     If the electronic zooming function has not been turned on, the second transfer unit  18  reads the Bayer data in units of eight lines from the memory  17  with the upper four lines being overlapped with the lower four lines of the upper block, as shown in  FIG. 5A . The second transfer unit  18  then transfers this block to the Bayer/YUV converting unit  19 .  
         [0113]     Thus, YUV data blocks sequentially generated by the Bayer/YUV converting unit  19  on the basis of the Bayer data contain no duplicate pixels. The YUV data blocks sequentially generated pass through the pixel number converting unit  31  and switch  22  to reach the third transfer unit  23 . The third transfer unit  23  transfers the data blocks to the memory  17 , where the data blocks are expanded and stored. The fourth transfer unit  24  then transfers the data blocks to the display control unit  25 . The liquid crystal monitor of this digital still camera subsequently displays and outputs the data blocks (step B 03 ).  
         [0114]     If it is determined at step B 01  that the electronic zooming function is turned on, the second transfer unit  18  reads every block of Bayer data comprising nine lines from the memory  17  as shown in  FIG. 8 . The second transfer unit  18  then transfers this block to the Bayer/YUV converting unit  19 .  
         [0115]     For example, the pixels of the Bayer data are read by the second transfer unit  18  in the following order. For the first block with the range of lines C 1  to C 9  shown in  FIG. 9 , described above:  
         [0116]     (C 1 ,  1 )→(C 1 ,  2 )→(C 1 ,  3 )→(C 1 ,  4 )→(C 1 ,  5 )→(C 1 ,  6 )→(C 1 ,  7 )→(C 1 ,  8 )→(C 1 ,  9 )→(C 2 ,  1 )→(C 2 ,  2 )→ . . .  
         [0117]     For the second block the starting line of which is shifted downward by four lines and which has the range of lines C 5  to C 13 :  
         [0118]     (C 1 ,  5 )→(C 1 ,  6 )→(C 1 ,  7 )→(C 1 ,  8 )→(C 1 ,  9 )→(C 1 ,  10 )→(C 1 ,  11 )→(C 1 ,  12 )→(C 1 ,  13 )→(C 2 ,  5 )→(C 2 ,  6 )→ . . .  
         [0119]     Accordingly, the Bayer/YUV converting unit  19  generates five lines of YUV data from these nine lines of Bayer data. For example, the pixels of YUV data generated are transferred in the following order. For the first block:  
         [0120]     (C 3 ,  3 )→(C 3 ,  4 )→(C 3 ,  5 )→(C 3 ,  6 )→(C 3 ,  7 )→(C 4 ,  3 )→(C 4 ,  4 )→(C 4 ,  5 )→(C 4 ,  6 )→(C 4 ,  7 )→(C 5 ,  3 )→(C 5 ,  4 )→ . . .  
         [0121]     For the second block:  
         [0122]     (C 3 ,  7 )→(C 3 ,  8 )→(C 3 ,  9 )→(C 3 ,  10 )→(C 3 ,  11 )→(C 4 ,  7 )→(C 4 ,  8 )→(C 4 ,  9 )→(C 4 ,  10 )→(C 4 ,  11 )→(C 5 ,  7 )→(C 5 ,  8 )→ . . .  
         [0123]     In this manner, the YUV data in the block located at a certain position is generated so that the lowermost line of the data is overlapped with the uppermost line of the YUV data in the next block, as shown by the hatching in  FIG. 8 .  
         [0124]     On the YUV data block generated so as to contain one duplicate line, the pixel number converting unit  31  executes a pixel converting process including an image enlarging process corresponding to the current enlargement ratio. During this enlarging process, as specifically described above in the first embodiment, the YUV data block is intentionally transferred so as to partially overlap the following data block as described above. Consequently, when pixels lying between blocks are generated, a generated image is not degraded.  
         [0125]     Then, the third transfer unit  23  transfers YUV data blocks sequentially obtained through the enlarging process and each having an increased number of lines (pixels), to the memory  17 , where the data blocks are expanded and stored. The fourth transfer unit  24  then transfers each YUV data block to the display control unit  25 . The liquid crystal monitor of this digital still camera displays and outputs a required display range (step B 02 ).  
         [0126]     The monitor display process is thus executed at step B 02  or B 03  depending on whether or not the electronic zooming function is turned on. Then, while repeatedly executing a process of determining whether or not the shutter key included in the key input unit  29  is operated (step B 04 ) and if not, returning to the process starting with step B 01 , the apparatus waits for the shutter key to be operated.  
         [0127]     If it is determined at step B 04  that the shutter key is operated, then it is determined whether or not the electronic zooming function is turned on (step B 05 ).  
         [0128]     If the electronic zooming function has not been turned on, a normal image recording process is executed. That is, Bayer data obtained through an image pick-up operation performed by the CCD  12  at a next timing will be transmitted to the first transfer unit  16  via the sample and hold circuit  13 , A/D converter  14 , and line processing unit  15 . The first transfer unit  16  then transfers the Bayer data to the memory  17  for storage. Then, the second transfer unit  18  reads every block of the Bayer data comprising eight lines from the memory  17 . Subsequently, the Bayer/YUV converting unit  19  generates the YUV data blocks each comprising four lines and having no duplicate lines as shown in  FIG. 5A .  
         [0129]     The YUV data blocks sequentially generated by the Bayer/YUV converting unit  19  and each comprising four lines are sequentially transferred to the JPEG processing unit  21  via the switch  20 . The JPEG processing unit  21  executes a data compressing process on the YUV data in units of two blocks each comprising eight lines to obtain JPEG data in units block (step B 08 ).  
         [0130]     The fifth transfer unit  26  then transfers one frame of JPEG data to the memory  17  for storage and then records these data in the memory card (step B 09 ).  
         [0131]     Once the normal image recording process is executed, the process returns to step B 01  to provide for the next pick-up session.  
         [0132]     If it is determined at step B 05  that the electronic zooming function is turned on when the shutter key is operated, then it is determined whether or not the enlargement ratio specified by operating the zoom key is set at just 1:2 (step B 06 ).  
         [0133]     If the enlargement ratio is not set to 1:2, an image recording process including an image enlarging process is executed. The Bayer data obtained through an image pick-up operation performed by the CCD  12  at a next timing will be transmitted to the first transfer unit  16  via the sample and hold circuit  13 , A/D converter  14 , and line processing unit  15 . The first transfer unit  16  then transfers the Bayer data to the memory  17  for storage. Then, the second transfer unit  18  reads every block of the Bayer data comprising nine lines from the memory  17 . Subsequently, the Bayer/YUV converting unit  19  generates YUV data blocks each comprising five lines including one duplicate line as shown in  FIG. 8 .  
         [0134]     The pixel number converting unit  31  then enlarges the YUV data block generated by the Bayer/YUV converting unit  19  and comprising five lines, so as to increase the number of pixels (lines) according to the currently set enlargement ratio. Then, the pixel number converting unit  31  sequentially transfers the YUV data to a buffer memory (not shown) via the switch  20 . The YUV data is expanded and stored in the buffer memory until storage of one frame of data is completed.  
         [0135]     Once one frame of YUV data is stored in the buffer memory, eight lines of YUV data, which are suitable for a JPEG process, are read from the buffer memory and transferred to the JPEG processing unit  21 . The JPEG processing unit  21  compresses the transferred data to generate the JPEG data (step B 07 ).  
         [0136]     Thereafter, the fifth transfer unit  26  transfers the JPEG data thus generated to the memory  17  for storage and then records the data in the memory card (step B 09 ). Once the image recording process including the image enlarging process is executed, the process returns to step B 01  to provide for the next pick-up session.  
         [0137]     If it is determined at step B 06  that the electronic zooming function is turned on and that the enlargement ratio is set to just 1:2, an image recording process including an image enlarging process is executed. The Bayer data obtained through an image pick-up operation performed by the CCD  12  at a next timing will be transmitted to the first transfer unit  16  via the sample and hold circuit  13 , A/D converter  14 , and line processing unit  15 . The first transfer unit  16  then transfers the Bayer data to the memory  17  for storage. Then, the second transfer unit  18  reads every block of the Bayer data comprising nine lines from the memory  17 . Subsequently, the Bayer/YUV converting unit  19  generates YUV data blocks each comprising five lines including one duplicate line as shown in  FIG. 8 .  
         [0138]     The YUV data blocks generated by the Bayer/YUV converting unit  19  and each comprising five lines are sequentially supplied to the pixel number converting unit  31 . The pixel number converting unit  31  then enlarges the data so as to increase the number of pixels according to the currently set enlargement ratio. Then, the pixel number converting unit  31  sequentially transfers the YUV data obtained and formed of blocks each comprising eight lines, to the JPEG processing unit  21 .  
         [0139]     That is, one YUV data block input to the pixel number converting unit  31  comprises five lines, or four lines if the line overlapped with the adjacent block is excluded. In contrast, YUV data output by the pixel number converting unit  31  has their size doubled (interpolating process). Accordingly, one output YUV data block comprises eight lines, which is double the size of the input YUV data block, if the line overlapped with the adjacent block is excluded. This size is suitable for 8×8 pixels, a basic process unit for the JPEG process. In this case, the output data is transferred directly to the JPEG processing unit  21 . The JPEG processing unit  21  then compresses the transferred data to generate the JPEG data in block units (step B 08 ).  
         [0140]     The fifth transfer unit  26  transfers the JPEG data thus generated to the memory  17  for storage and then records the data in the memory card (step B 09 ). Once the image recording process including the image enlarging process is executed, the process returns to step B 01  to provide for the next pick-up session.  
         [0141]     In this manner, the pixel number converting unit  31  is placed immediately succeeding to the Bayer/YUV converting unit  19  so that YUV data can be immediately compressed by the JPEG processing unit  21  without expanding one frame of the YUV data on the buffer memory with regard to the data that is not enlarged or is enlarged at a particular ratio. Therefore, the circuit configuration can be simplified to allow image data to be recorded on a medium in a shorter time.  
         [0142]     In the second embodiment, the YUV data is generated so that each block data contains duplicate lines. However, even if YUV data is generated so as to contain no duplicate lines as described in  FIG. 5A , similar effects are produced in that YUV data enlarged at a particular ratio can be transferred directly to the JPEG processing unit.  
       Third Embodiment  
       [0143]      FIG. 12  shows the configuration of a circuit that is basically similar to that of the first and second embodiments shown in  FIGS. 6 and 10 .  
         [0144]     The YUV data output by the Bayer/YUV converting unit  19  is supplied to the pixel number converting unit  31  and switch  22 . The pixel number converting unit  31  transmits its outputs directly and only to the JPEG processing unit  21  without transmitting via the switch  20 .  
         [0145]     Further, a pixel number converting unit  32  configured similarly to the pixel number converting unit  31  is placed succeeding to the switch  22 . If the electronic zooming function is turned on, the pixel number converting unit  32  enlarges the YUV data transmitted via the switch  22  and then transfers the enlarged data to the third transfer unit  23 . The third transfer unit  23  transfers the data to the memory  17 , where the data is expanded and stored.  
         [0146]     Now, the operation of this embodiment will be described.  
         [0147]      FIG. 13  illustrates the specific contents of an enlarging process for electronic zooming executed by the pixel number converting units  31  and  32 . For simplification, it is assumed that one YUV data block input to the pixel number converting unit  31  ( 32 ) comprises three lines and that this block has three pixels arranged in the vertical direction. It is further assumed that one block contains one duplicate line, which is enlarged and converted into three or four pixels by the pixel number converting unit  31 .  
         [0148]     Reference characters P 1  to P 5  denote pixel data input by the Bayer/YUV converting unit  19  and which has not been enlarged yet.  
         [0149]     For the first block, lines corresponding to pixels P 1  to P 3  arranged in the vertical direction are input; for the second block, lines corresponding to pixels P 3  to P 5 , each of which deviates from the corresponding pixel of the first block by two pixels, are input; for the subsequent block, lines corresponding to pixels P 5  to P 7  are input, etc. In this manner, pixels are input so that a line corresponding to one pixel is duplicated between adjacent blocks.  
         [0150]     If new pixel is generated between two vertically adjacent pixels by an enlarging process, the points at which the difference between values for these two pixels is divided into 16 equal parts are determined by a sampling operation.  FIG. 13  illustrates an enlarging process at an enlarging ratio of 16/10.  
         [0151]     If a pixel P 1  is first selected and new pixels are subsequently generated at the pixel intervals of 10/16, then the positions of the new pixels are as shown by the black points BP 1 , BP 2 , . . . in  FIG. 13 . For example, between points P 4  and P 5 , pixels are generated at the positions of the two new black points BP 6  and BP 7 . In this case, values for these new pixels are each determined as shown in the following sampling operations so as to precisely reflect the contents of a value for the corresponding original pixel, which is closer to this new pixel on the basis of the distance to the original pixel. 
 
 BP 6=( P 4×14+ P 5×2)/16 
 
 BP 7=( P 4×4+ P 5×12)/16 
 
         [0152]     As shown in  FIG. 13 , pixel values for the four black points BP 1  to BP 4 , including the original pixel P 1 , are generated from the first block, comprising the pixels P 1  to P 3 . On the other hand, pixel values for the three black points BP 5  to BP 7  are generated from the second block, comprising the pixels P 3  to P 5 .  
         [0153]     In this case, only the enlargement in the vertical direction is considered. Here, it is assumed that the original YUV data contains 100 pixels in the horizontal direction and that no enlarging process is executed in the horizontal direction. Then, an enlarging process executed on the entire first block results in 400 pixels, whereas an enlarging process executed on the entire second block results in 300 pixels. These pixels are transferred in the order as shown in  FIG. 3 .  
         [0154]      FIG. 14  illustrates the configuration of a circuit provided in each of the pixel number converting units  31  and  32  to determine extracted pixels as described above, i.e. the position of a black point BPi. In this circuit, an adder  42  adds 21 bits of values stored in an E register  41  that stores pixel intervals established after an enlarging process, to 22 bits of values stored in an A register  43 . The contents of the A register  43  are updated, so that this sum output is stored therein.  
         [0155]     The 22 bits of values stored in the A register  43  are output and fed back to the adder  42  as described above, while being output as extracted pixels. The A register  43  is partitioned into a B register  44 , a C register  45 , and a D register  46  as shown in  FIG. 14 .  
         [0156]     In this case, the B register  44  stores the higher 8 bits of the 22 bits to express the position of a line (a pixel in the vertical directions) in the original YUV data.  
         [0157]     The C register  45  stores 4 bits of the 22 bits which follow the 8 bits in the B register to express an offset position from the line position indicated by the B register, specifically, a value for one of the points at which the difference between values for two pixels are divided into 16 parts.  
         [0158]     The D register  46  stores the lower 10 bits of the 22 bits and is used as a dummy register to compensate for accuracy.  
         [0159]     For example, it is assumed that pixels are extracted as shown in  FIG. 13 . Then, the initial value “000000(H)” is input to the A register  43 , whereas the 21-bit numerical value “002800(H)” corresponding to the enlarged pixel interval “10(/16)” is set in the E register  41 .  
         [0160]     The higher 7 bits of the E register  41  form an integer part and are “000400(H)” in the case of an equal scale where no enlarging process is executed. Thus, the value “002800(H)” is set by: 
 
000400(H)×10/16. 
 
         [0161]     That is, for the first sampling position BP 1 , A=“000000(H)”, B=“00(H)”, and C=“0(H)”; for the second sampling position BP 2 , A+E=“002800(H)”, B=“00(H)”, and C=“a(H)” (=10); for the third sampling position BP 2 , A+E=“005000(H)”, B=“01(H)”, and C=“4(H)”, etc. In this manner, the contents of the A register  43  are sequentially increased by the value stored in the E register  41 , thereby allowing pixels to be extracted.  
         [0162]     After one vertical scanning operation is completed, the scanning operation shifts to the next pixel in the horizontal direction. Then, the contents of the A register  43  are initialized again to extract sampling positions.  
         [0163]     Further, before the block is switched, the value stored in the E register  41  is added again to the contents of the A register  46  when the A register  43  is initialized. Then, this sum output is used as an initial value for the new block.  
         [0164]     The accuracy of the operations involved in the above-described extraction of pixels varies depending on the size of the D register  46 . In this embodiment, this accuracy is 10 bits.  
         [0165]     The capacity of the B register  44  is set according to the maximum value of the number of pixels (=lines) in the vertical direction, which constitute one block of the original YUV data. For a practical reason, about 4 to 32 pixels are used, so that this register is set to have 8 bits so as to provide a sufficiently larger number of pixels.  
         [0166]     After the pixel number converting unit  31  ( 32 ) has thus extracted pixels and executed the corresponding image conversions as an enlarging process, it transfers the YUV data obtained to the buffer memory (not shown). Then, the data is sequentially expanded and stored therein until storage of one frame of data is completed.  
         [0167]     Once one frame of the YUV data has been stored in the buffer memory, the YUV data in units of eight lines, which is suitable for a JPEG process, is read from the buffer memory and transferred to the JPEG processing unit  21 . The JPEG processing unit  21  compresses the transferred data to generate the JPEG data.  
         [0168]     On the other hand, the third transfer unit  23  transfers the YUV data enlarged by the image converting unit  32  to the memory  17  for display. When the YUV data is transferred, line number data is also transferred for each block.  
         [0169]      FIG. 15  indicates that the line number data “LINECNT” is transferred concurrently with the YUV data “DATA”.  FIG. 15  also shows the reference clock “CLK”.  
         [0170]      FIG. 15  illustrates that the line number data comprises parallel data of 5-bits width on the assumption that one block can be enlarged so as to contain up to 16 pixels (lines).  
         [0171]      FIG. 16  indicates that to serially transfer the YUV data, the line number data “LINECET” is serially transferred synchronously with the enable signal “ENB” prior to the YUV data.  FIG. 16  also shows the reference clock “CLK”.  
         [0172]     In this manner, the number of pixels is increased or reduced by enlarging every block comprising a plurality of lines. If the number of lines constituting one block varies after the increase or reduction, this can be dealt with by outputting line number information to the following component.  
         [0173]     If an enlarging process for electronic zooming is executed using the same number of pixel lines for every block, then a numeral value that can be set as an enlargement ratio is restricted, for example, an integer ratio must be established between the number of pixels present prior to enlargement and the number of pixels present after enlargement. However, this invention is not restricted by the enlargement ratio specified for an enlarging process for electronic zooming but enables the electronic zooming function to be provided at various enlargement ratios.  
         [0174]     In the configuration shown in  FIG. 12 , the two pixel number converting units  31  and  32  are provided so that the pixel number converting unit  31  enlarges the YUV data to be compressed by the JPE processing unit  21  and then recorded in the memory card, while the pixel number converting unit  32  enlarges the YUV data to be displayed and output by the liquid crystal monitor or the like. This configuration is provided so as to execute, in parallel, the processes of displaying the YUV data on the monitor and recording the YUV data in the medium, which processes the YUV data comprising different numbers of pixels, thereby allowing the digital still camera to respond quickly without wasting time.  
         [0175]     In the third embodiment, as in the first and second embodiments, the YUV data is generated so that each block thereof has lines overlapped with the next block. However, the YUV data may be generated so that blocks thereof contain no duplicate lines. In this case, different enlargement ratios are used to enlarge the respective blocks, thereby allowing various enlargement ratios for electronic zooming to be accommodated.  
         [0176]     In the first to third embodiments, the present invention is applied to image data picked up by the CCD  12  in the pick-up mode. However, the present invention is also applicable to the image data read from a memory card in a reproduction mode.  
         [0177]     In the first to third embodiments, the present invention is applied to a digital still camera. However, of course, the present invention is applicable to any image processing apparatus such as a digital movie camera, a television apparatus, or an image reproducing apparatus that has an electronic zooming function.  
         [0178]     Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.