JP2010067157A - Image processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make inconspicuous image misalignment and fluctuation when displaying a decoded enlarged image instead of a transitional zooming display operation. <P>SOLUTION: When an enlargement operation is started by a user, a transitional zooming display operation is performed in which an interpolating and enlarging part 106 interpolates and enlarges a decoded image displayed in a display part 110 at that time to display the decoded image while the enlargement operation is continued. The interpolating and enlarging part 106 can select a mode A for arranging a reference pixel between dots of a pixel of an interpolated and enlarged image or a mode B for arranging the reference pixel on a dot of the pixel of the interpolated and enlarged image. A mode selecting part 116 selects either mode A or B in accordance with an encoding method of a code or the like. When the enlargement operation ends, a decoding part 102 decodes the code to be enlarged to decode the enlarged image, and displays the image to be overwritten on the interpolated and enlarged image. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image processing apparatus that decodes and displays an image given as a compressed code, and more particularly to an image processing apparatus that can perform an enlargement operation of a display image.

  When browsing an image in the image database, the user needs to search for a target image. As a method of searching for an image, if the image name (file name) of the search target image is known, the image may be searched from a list of image names. In many cases, a list display of thumbnails is used. For example, when searching for a document image, a candidate image that has been hit by a keyword after a keyword search is displayed in a thumbnail list, and finally a search target image is selected. A method of searching for an image is used. In such a thumbnail list display, it is difficult to grasp the detailed contents of the image because it is a reduced image state with a reduced resolution, so it is necessary to display the image in an enlarged manner.

  There are many cases where enlargement display of an image is required in this way. However, since an image is usually stored and transmitted as a compressed code, a code decoding process is performed to obtain an image of a certain resolution when an enlargement operation is performed from a low resolution to a high resolution in stages. Next, if a code decoding process for obtaining an image with a higher resolution is performed, and the decoding process is performed many times in succession, the process takes time, and high-speed zooming is difficult. Therefore, during the enlargement operation, a “transient zooming display operation” that displays an image obtained by enlarging the low-resolution decoded image by image interpolation is performed, and when the enlargement operation is completed, the final high-resolution image display is performed. A technique of performing necessary code decoding processing and updating the display with the decoded high-resolution image is used (see, for example, Patent Document 1).

JP-A-10-198337

  There may be a phenomenon in which the entire image shifts or shakes at the moment of switching from the interpolated enlarged image by the “transient zooming display operation” described above to the display of a decoded image of high resolution. An object of the present invention is to suppress the occurrence of such “shift” or “sway” of an image.

  First, a mechanism of occurrence of a phenomenon that appears to be shifted or shaken at the moment when an interpolation enlarged image displayed by a transient zooming display operation is replaced with a high-resolution decoded image will be briefly described.

  For example, the lossless compression mode of JPEG2000 uses a reversible discrete wavelet transform (DWT) using a 5/3 filter, and a one-dimensional reversible discrete wavelet transform is applied in the vertical direction and the horizontal direction, respectively. Usually, a lifting operation that omits the calculation in consideration of the downsampling after the discrete wavelet transform is used. This lifting operation is given by the following equation.

  After performing the lifting operation in the vertical and horizontal directions, it is deinterleaved and divided into subbands as shown in FIG. In FIG. 4, LL is a low frequency component in both the vertical and horizontal directions, HL is a signal obtained by extracting a horizontal high frequency component from a vertical low frequency component, and LH is a horizontal low frequency component extracted from a vertical high frequency component. A signal, HH, is a signal obtained by extracting high-frequency components in both vertical and horizontal directions.

  When generating a low-resolution image, only the LL component is used. Interpolating and enlarging using low-resolution pixel values during zooming is nothing other than image interpolation using the LL component values as pixel values.

  Here, for simplicity, the signal is limited to one dimension. When 5/3 reversible DWT is applied to the one-dimensional original data as shown in FIG. 5 to extract low frequency components, the result is as shown in FIG. The extracted low frequency component is a pixel value before zooming, and the pixel value is used to perform interpolation enlargement twice.

  FIG. 7 shows a comparison with original data in the case of using a nearest neighbor as an image interpolation method. Nearest neighbor uses the same value as the even-numbered pixel of the original data for the odd-numbered pixel next to it, so in addition to giving the impression that the image quality is dirty, the odd-numbered pixel when overlapping high-resolution images in the first place Since the pixel value is corrected to the original value, it appears to shift to the left. A phenomenon that appears to be shifted to the left in the one-dimensional data appears to be shifted to the upper left in the two-dimensional image.

  When the 5/3 reversible DWT is applied twice and the extracted low-frequency component is interpolated and expanded by the nearest neighbor method and compared with the original data, the result is as shown in FIG. .

  The example using the nearest neighbor has been described so far, but the same phenomenon occurs when using an image interpolation method that determines the value of an interpolation pixel by calculation using the values of a plurality of reference pixels. The data that has been interpolated and enlarged by the bilinear method widely used as such an image interpolation method is usually as shown in FIG. 9, and the original data (high-resolution image) is generally on the left side compared to the data that has been interpolated and enlarged. Sneak away.

  This will be further described. In the bilinear method, an interpolation pixel value is determined by linear approximation from the values of reference pixels in the vicinity of 4 of the interpolation pixel. When the input image f (i, j) is multiplied by A in the horizontal and vertical directions, four reference pixels (the upper left one is f00, the upper right one is f10, the lower left one is f01, and the lower right one is f11). ) Etc. are defined as follows:

補間画素の値は次式により計算される。

The value of the interpolated pixel is calculated by the following equation.

  Here, in the bilinear method, the position of the reference pixel and the interpolation pixel is not shown using the same grid, but as shown in FIG. 10, the reference pixel is located between the grid points of the pixels of the interpolation enlarged image. (FIG. 10 shows an example of A = 2). Therefore, in this case, for example, the value of the interpolation pixel g00 is calculated by the following equation.

  Such an arrangement of the reference pixels means that the reference pixels are handled like representative pixels that exist virtually in the center of 2 × 2 pixels of the original data (high resolution image). However, the low-frequency component obtained by the 5/3 reversible DWT is calculated from the pixels centered on the down-sampled pixel, so that a value close to the even-numbered pixel value becomes the low-frequency component. When image interpolation is performed such that reference pixels are arranged between lattice points of an interpolated image as shown in FIG. 10 using low frequency components obtained by 3 reversible DWT, as shown in FIG. A gap is generated between the high-resolution image) and the interpolated enlarged image, and when the high-resolution image is overwritten and displayed on the interpolated enlarged image, the image appears to be shifted to the upper left.

  Such “shift” or “shake” of the image can be prevented by arranging the reference pixel on the grid point of the pixel of the interpolation enlarged image as shown in FIG. 11 (A = 2 in FIG. 11). ). When the reference pixels are arranged in this way, the calculation formulas for the interpolation pixels g00, g10, g01, and g11 are expressed as follows, and the value of the reference pixel is used as the even-numbered interpolation pixel value, and the odd-numbered interpolation is performed. The pixel value is determined using the values of the reference pixels on both sides.

  As described above, the result of performing the interpolation enlargement by the bilinear method by arranging the reference pixel on the lattice point of the pixel of the interpolation enlarged image is as shown in FIG. 12, and changes almost the same as the original data. Therefore, the momentary shift or shake of overwriting the high-resolution image on the interpolated enlarged image is inconspicuous.

  In JPEG2000, 5/3 reversible DWT and 9/7 irreversible DWT can be used as frequency conversion. Regardless of which one is selected, pixels of a low resolution image are obtained from an odd number of pixel values of a high resolution image. This is common in that it is a transformation that generates a value.

  Next, a description will be given of a case of an image code of an encoding method in which conversion for generating a pixel value of a low resolution image from an even number of pixel values of a high resolution image is used. An example of such an encoding method is JPEG-XR, which is currently being standardized.

  In the case of an image code based on JPEG-XR, a code that can obtain an image with the highest resolution and a 1/4 scale and a code that can obtain an image with a 1/16 scale can be extracted from one code. In the case of a JPEG-XR image code, the frequency hierarchy is as shown in FIG. 13, and the coefficient after orthogonal transformation is performed in units of 4 × 4 pixel blocks is expressed in units of 4 × 4 blocks (macro blocks). The result of the orthogonal transformation in units of 4x4 with respect to LP as the coefficient HP of the highest resolution and the coefficient DC of the coefficient of each block of the macroblock as the coefficient LP of one step lower resolution. Treat the resulting DC component as the lowest resolution coefficient DC.

Here, LP is a coefficient representing a flattened block of 4 pixels × 4 pixels. Therefore, an HP coefficient is added to an image obtained by interpolating and enlarging a low resolution image decoded using only LP using the bilinear method. In order to prevent the image from being shifted when the high-resolution image decoded using all of the above is overwritten, contrary to the case of JPEG2000, as shown in FIG. Interpolation enlargement may be performed by arranging reference pixels.
Another example of a similar code is the FlashPix code.

  In the above description, it is assumed that a compressed image is given as a resolution scalable code. However, a compressed image given as a collection of independent codes of a plurality of different resolution images obtained by resolution conversion that generates pixel values of a low resolution image from odd pixel values of a high resolution image is a JPEG2000 code. Similar to the above, if reference enlargement is performed by arranging reference pixels on the pixel grid points of the interpolation enlarged image, the image shift when the interpolation enlarged image is overwritten with the high-resolution decoded image becomes inconspicuous. On the other hand, a compressed image given as a collection of independent codes of a plurality of different resolution images obtained by resolution conversion that generates pixel values of a low resolution image from an even number of pixel values of a high resolution image is JPEG- It can be handled in the same way as an XR code or the like, and interpolation enlargement may be performed by arranging reference pixels between lattice points of pixels of the interpolation enlarged image.

  As described above, the bilinear method is taken as an example of the image interpolation method, but the same applies when the bicubic method or the like is used.

  Based on the above considerations, the present invention realizes an image processing device that suppresses the occurrence of image shift or shaking at the moment of switching from an interpolated enlarged image by a transient zooming display operation to a display of a high-resolution decoded image. The features are as follows.

The invention described in claim 1
When the enlargement operation by the user is started in a state where the decoded image obtained by the decoding process of the code that is the target of the enlargement operation is displayed, an interpolation enlargement process of the decoded image is performed while the enlargement operation is continued. A transient zooming display operation for displaying the obtained interpolated enlarged image is performed, and when the enlargement operation is completed, the code that is the target of the enlargement operation is decoded, and the obtained decoded image is converted to the transient zooming An image processing apparatus for displaying in an overwritten form on the interpolation enlarged image displayed at the end of the display operation,
The interpolation enlargement process is a process by an image interpolation method that determines the value of each pixel of the interpolation enlarged image by calculation using the values of a plurality of reference pixels.
The interpolation enlargement means for performing the interpolation enlargement process is an A mode in which the reference pixels are arranged between the lattice points of the pixels of the interpolation enlarged image as an operation mode related to the positional relationship between the reference pixels and the pixels of the interpolation enlarged image, or The B mode in which the reference pixel is arranged on the lattice point of the pixel of the interpolation enlarged image can be selected.
An image processing apparatus comprising mode selection means for selecting either the A mode or the B mode as an operation mode of the interpolation enlargement means in accordance with a user instruction.

The invention according to claim 2
When the enlargement operation by the user is started in a state where the decoded image obtained by the decoding process of the code that is the target of the enlargement operation is displayed, an interpolation enlargement process of the decoded image is performed while the enlargement operation is continued. A transient zooming display operation for displaying the obtained interpolated enlarged image is performed, and when the enlargement operation is completed, the code that is the target of the enlargement operation is decoded, and the obtained decoded image is converted to the transient zooming An image processing apparatus for displaying in an overwritten form on the interpolation enlarged image displayed at the end of the display operation,
The interpolation enlargement process is a process by an image interpolation method that determines the value of each pixel of the interpolation enlarged image by calculation using the values of a plurality of reference pixels in the vicinity thereof,
The interpolation enlargement means for performing the interpolation enlargement process is an A mode in which the reference pixels are arranged between the lattice points of the pixels of the interpolation enlarged image as an operation mode related to the positional relationship between the reference pixels and the pixels of the interpolation enlarged image, or The B mode in which the reference pixel is arranged on the lattice point of the pixel of the interpolation enlarged image can be selected.
An image processing apparatus comprising mode selection means for automatically selecting one of the A mode and B mode as an operation mode of the interpolation enlargement means.

According to a third aspect of the present invention, in the image processing apparatus according to the second aspect of the present invention,
The mode selection means, when a resolution scalable code by an encoding method using a conversion that generates a pixel value of a low resolution image from an odd number of pixel values of a high resolution image is an object of an enlargement operation, The B mode is selected as the operation mode of the interpolation enlarging means, and the resolution scalable code by the encoding method using the conversion that generates the pixel value of the low resolution image from the even number of pixel values of the high resolution image is enlarged. In the case of A, the A mode is selected as the operation mode of the interpolation enlarging means.

According to a fourth aspect of the present invention, in the image processing apparatus according to the second aspect of the present invention,
In the mode selection means, an independent code of each of a plurality of different resolution images obtained by resolution conversion that generates pixel values of a low resolution image from an odd number of pixel values of a high resolution image is an object of an enlargement operation. In this case, the B mode is selected as the operation mode of the interpolation enlargement means, and a plurality of different resolution images obtained by resolution conversion for generating pixel values of a low resolution image from an even number of pixel values of a high resolution image. When each independent code is an object of the enlargement operation, the A mode is selected as the operation mode of the interpolation enlargement means.

According to a fifth aspect of the present invention, in the image processing apparatus according to the third or fourth aspect of the present invention,
When there are a plurality of enlargement operation targets, the mode selection means automatically selects either the A mode or the B mode as the operation mode of the interpolation enlargement means for each target.

  According to the present invention, it is possible to realize an image processing apparatus capable of suppressing the occurrence of image shift or shaking at the moment of switching from an interpolated enlarged image by a transient zooming display operation to a display of a high-resolution decoded image. Can do.

  FIG. 1 is a block diagram for explaining an image processing apparatus according to an embodiment of the present invention. The image processing apparatus includes a code storage unit 100 for storing a code of an image, a decoding unit 102 that reads a code stored in the code storage unit 100, performs a decoding process, and outputs a decoded image, and temporarily stores the decoded image. A decoded image storage unit 104 for storing the decoded image, an interpolation expansion unit 106 that reads the decoded image from the decoded image storage unit 104, performs an interpolation enlargement process, and outputs an interpolation enlarged image, and temporarily stores the interpolation enlarged image Control of the display unit 110, the decoding unit 102, the interpolation enlargement unit 106, and the display unit 110 that display the image stored in the interpolation enlarged image storage unit 108, the decoded image storage unit 104, or the interpolation enlarged image storage unit 108 on the screen. The control unit 112 performs a user operation unit 114 for a user to perform an enlargement operation or the like. On the screen of the display unit 110, only one image may be displayed or a plurality of images may be displayed simultaneously. The user can enlarge only one image displayed on the screen or enlarge a plurality of images at the same time by an enlargement operation by the user operation unit 114.

  As codes stored in the code storage unit 100, resolution-scalable codes such as JPEG2000 codes, JPEG-XR codes, and FlashPix codes are usually assumed. However, it may be a collection of independent codes (for example, JPEG codes) of a plurality of different resolution images obtained by applying resolution conversion for converting a high resolution image to a low resolution.

  The interpolation enlargement unit 106 uses an image interpolation method, for example, a bilinear method, in which an interpolation pixel value is determined by calculation using values of a plurality of reference pixels in the vicinity thereof. Then, the interpolation enlargement unit 106 arranges the reference pixels between the lattice points of the pixels of the interpolation enlarged image as illustrated in FIG. 10 as the operation mode related to the positional relationship between the reference pixels and the pixels of the interpolation enlarged image. The A mode can be selected, or the B mode in which the reference pixels are arranged on the grid points of the pixels of the interpolation enlarged image as illustrated in FIG. 11 can be selected.

  The control unit 112 includes a mode selection unit 116 that selects a mode for operating the interpolation enlargement unit 106 in either the A or B mode. This mode selection can be performed based on an instruction from the user, or can be automatically performed according to a target code.

  Such an image processing apparatus uses, for example, a general computer including a CPU 200, a memory 202, a display 204, a mouse 206, a keyboard 208, a hard disk 210, a network interface 212, etc. as shown in FIG. It is realized by. A specific storage area of the memory 202 is used as each storage unit 100, 104, 108. For example, the mouse 206 is used as the user operation unit 114, and the user's enlargement operation is an operation of rotating the wheel of the mouse 206, for example. The displayed image code may be stored in the hard disk 210 or downloaded from a remote server or the like through the network interface 212.

  For example, the user's enlargement operation is performed in a state where a low-resolution decoded image (stored in the decoded image storage unit 104) obtained by the decoding process of the resolution scalable code is displayed on the screen of the display unit 110. The operation in this case will be described with reference to the state transition diagram of FIG.

  When the user starts the enlargement operation with the user operation unit 114 in the operation waiting state S0 in which the low-resolution decoded image obtained by the decoding process of the code that is the target of the enlargement operation is displayed, the control unit 112 performs the enlargement operation. Transition to the middle state S1. Here, the enlargement operation is an operation for rotating the wheel of the mouse 206.

  In state S <b> 1, the control unit 112 causes the interpolation enlargement unit 106 to specify the enlargement magnification and perform the interpolation enlargement process of the decoded image in the decoded image storage unit 104, and outputs the interpolation enlarged image to the interpolation enlarged image storage unit 108. The interpolated enlarged image is displayed on the screen of the display unit 110. While the enlargement operation continues, the enlargement magnification is gradually increased to repeatedly perform the interpolation enlargement process and the display of the enlarged interpolation image. That is, a transient zooming display operation is performed.

  When the user's enlargement operation is completed (specifically, when the user releases his / her finger from the wheel of the mouse 206), the control unit 112 transitions to the state S2. The control unit 112 performs a decoding process on the code to obtain a high-resolution image (enlarged image) corresponding to the size of the interpolated enlarged image displayed at the end of the transient zooming display operation for the code. Then, the high-resolution decoded image output from the decoding unit 102 and stored in the decoded image storage unit 104 is displayed on the screen of the display unit 110 so as to overwrite the interpolated enlarged image displayed so far. When this process ends, the process returns to the operation waiting state S0.

  The mode selection unit 116 selects whether the interpolation enlargement unit 106 operates in the A mode or the B mode in the transient zooming display operation. When the encoding method of the code that is the target of the enlargement operation is determined in advance, the user side, for example, the user operation unit 114 may select a specific mode suitable for the encoding method by the mode selection unit 116. An instruction can be given in advance through the operation.

  In other words, when a resolution scalable code such as a JPEG2000 code using an encoding method that uses a conversion that generates a pixel value of a low resolution image from an odd number of pixel values of a high resolution image is the target of an enlargement operation ( Alternatively, in the case where independent codes of a plurality of different resolution images obtained by the same resolution conversion are objects of enlargement operation), the B mode in which the reference pixels are arranged on the lattice points of the pixels of the interpolation enlarged image is selected. It only has to be instructed to select. If such a mode is selected, the image shift when the high-resolution decoded image is overwritten and displayed on the interpolated enlarged image displayed last in the transient zooming display operation becomes inconspicuous.

  On the other hand, a resolution scalable code such as a JPEG-XR code or a FlashPix code is used as an enlargement operation by an encoding method in which a conversion for generating a pixel value of a low resolution image from an even number of pixel values of a high resolution image is used. In some cases (or in the case where independent codes of a plurality of different resolution images obtained by the same resolution conversion are the targets of the enlargement operation), the reference pixel is between the lattice points of the interpolated enlarged image pixels. May be instructed to select the A mode in which to place the If such a mode selection is performed, the image shift or shake when the high resolution decoded image is overwritten and displayed on the interpolated enlarged image displayed at the end of the transient zooming display operation becomes inconspicuous.

  In addition, the user can instruct the mode selection unit 116 to automatically select a mode suitable for the code to be subjected to the enlargement operation through the operation of the user operation unit 114. In this case, the mode selection unit 116 performs an enlargement operation on a resolution-scalable code such as a JPEG2000 code based on an encoding method that uses conversion that generates a pixel value of a low-resolution image from an odd number of pixel values of a high-resolution image. If it is the target (or if the independent codes of a plurality of different resolution images obtained by the same resolution conversion are the targets of the enlargement operation), the B mode is automatically selected, and an even number of high resolution images If a resolution-scalable code based on an encoding method that uses conversion that generates pixel values of a low-resolution image from a single pixel value, for example, a JPEG-XR code or a FlashPix code, is the target of an enlargement operation (or similar When the independent codes of multiple different resolution images obtained by resolution conversion are subject to enlargement operation ) To automatically select the A mode.

  Such automatic mode selection is, for example, information on the encoding method described in the code header, information on the mode selection previously described in the code header, or A or B mode for each code. This can be easily done by referring to information in a table prepared for managing whether to apply. If such automatic mode selection is performed, the high-resolution decoded image is displayed on the interpolated enlarged image displayed by the transient zooming display operation without the user being aware of the encoding method of the target code. It is possible to make the shift or shake of the image inconspicuous when overwritten.

  A plurality of images displayed on the screen of the display unit 110 can be enlarged and displayed at the same time by the user's enlargement operation. As described above, even when there are a plurality of enlargement operation targets, the mode selection unit 116 appropriately selects the interpolation enlargement processing mode in the transient zooming display for each enlargement operation target, thereby obtaining a high resolution for the interpolation enlargement image. It is possible to make the image shift inconspicuous when the decoded image is overwritten and displayed. When different images such as encoding methods are mixed in the enlargement operation target, it is necessary to select a mode suitable for each image, but this is possible by the automatic mode selection described above.

  The present invention is not limited to the above-described embodiment, and can be implemented with various modifications.

1 is a block diagram of an image processing apparatus of the present invention. It is a block diagram which shows an example of the computer by which the image processing apparatus of this invention is implement | achieved. It is a state transition diagram for demonstrating the operation | movement relevant to expansion operation. It is a figure which shows the subband division | segmentation after applying two-dimensional DWT once. It is a figure which shows the one-dimensional original data used as the object of 5 / 3DWT. It is the figure which plotted the original data and the low frequency component of the data after applying 5 / 3DWT to it. It is the figure which plotted the original data and the data which expanded the low frequency component of the data after applying 5 / 3DWT to it 2 times by the near neighbor. It is the figure which plotted the original data and the data which expanded the low frequency component of the data after applying 5 / 3DWT twice to it by the near-less tray bar twice. It is the figure which plotted the original data and the data which expanded the low frequency component of the data after applying 5 / 3DWT to it twice bilinearly. It is explanatory drawing of the mode which arrange | positions a reference pixel between the lattice points of the pixel of an interpolation image in a bilinear method. It is explanatory drawing of the mode which arrange | positions a reference pixel on the lattice point of the pixel of an interpolation image in a bilinear method. A plot of original data and data obtained by enlarging the low-frequency component of the data after applying 5 / 3DWT to it twice in a mode in which reference pixels are arranged on the lattice points of the pixels of the interpolation image by the bilinear method. It is. It is explanatory drawing of the frequency hierarchy of JPEG-XR.

Explanation of symbols

100 Code storage unit 102 Decoding unit 104 Decoded image storage unit 106 Interpolation enlargement unit 108 Interpolation enlarged image storage unit 110 Display unit 112 Control unit 114 User operation unit 116 Mode selection unit

Claims (5)

When the enlargement operation by the user is started in a state where the decoded image obtained by the decoding process of the code that is the target of the enlargement operation is displayed, an interpolation enlargement process of the decoded image is performed while the enlargement operation is continued. A transient zooming display operation for displaying the obtained interpolated enlarged image is performed, and when the enlargement operation is completed, the code that is the target of the enlargement operation is decoded, and the obtained decoded image is converted to the transient zooming. An image processing apparatus for displaying in an overwritten form on the interpolation enlarged image displayed at the end of the display operation,
The interpolation enlargement process is a process by an image interpolation method that determines the value of each pixel of the interpolation enlarged image by calculation using the values of a plurality of reference pixels.
The interpolation enlargement means for performing the interpolation enlargement process is an A mode in which the reference pixels are arranged between the lattice points of the pixels of the interpolation enlarged image as an operation mode related to the positional relationship between the reference pixels and the pixels of the interpolation enlarged image, or The B mode in which the reference pixel is arranged on the lattice point of the pixel of the interpolation enlarged image can be selected.
An image processing apparatus comprising mode selection means for selecting either the A mode or the B mode as an operation mode of the interpolation enlargement means in accordance with a user instruction. When the enlargement operation by the user is started in a state where the decoded image obtained by the decoding process of the code that is the target of the enlargement operation is displayed, an interpolation enlargement process of the decoded image is performed while the enlargement operation is continued. A transient zooming display operation for displaying the obtained interpolated enlarged image is performed, and when the enlargement operation is completed, the code that is the target of the enlargement operation is decoded, and the obtained decoded image is converted to the transient zooming. An image processing apparatus for displaying in an overwritten form on the interpolation enlarged image displayed at the end of the display operation,
The interpolation enlargement process is a process by an image interpolation method that determines the value of each pixel of the interpolation enlarged image by calculation using the values of a plurality of reference pixels in the vicinity thereof,
The interpolation enlargement means for performing the interpolation enlargement process is an A mode in which the reference pixels are arranged between the lattice points of the pixels of the interpolation enlarged image as an operation mode related to the positional relationship between the reference pixels and the pixels of the interpolation enlarged image, or The B mode in which the reference pixel is arranged on the lattice point of the pixel of the interpolation enlarged image can be selected.
An image processing apparatus comprising mode selection means for automatically selecting one of the A mode and B mode as an operation mode of the interpolation enlargement means.   The mode selection means, when a resolution scalable code by an encoding method using a conversion that generates a pixel value of a low resolution image from an odd number of pixel values of a high resolution image is an object of an enlargement operation, The B mode is selected as the operation mode of the interpolation enlarging means, and the resolution scalable code by the encoding method using the conversion that generates the pixel value of the low resolution image from the even number of pixel values of the high resolution image is enlarged. The image processing apparatus according to claim 2, wherein an A mode is selected as an operation mode of the interpolation enlarging means.   In the mode selection means, an independent code of each of a plurality of different resolution images obtained by resolution conversion that generates pixel values of a low resolution image from an odd number of pixel values of a high resolution image is an object of an enlargement operation. In this case, the B mode is selected as the operation mode of the interpolation enlargement means, and a plurality of different resolution images obtained by resolution conversion for generating pixel values of a low resolution image from an even number of pixel values of a high resolution image. The image processing apparatus according to claim 2, wherein when each independent code is an object of an enlargement operation, an A mode is selected as an operation mode of the interpolation enlargement unit.   4. When there are a plurality of enlargement operation targets, for each of the targets, the mode selection unit automatically selects either the A mode or the B mode as the operation mode of the interpolation enlargement unit. 5. The image processing apparatus according to 4.

Images