JP3977300B2 - Printing control apparatus and control method therefor - Google Patents

Description

    The present invention relates to a technique for printing a compressed image.

  Conventionally, in order to print an image stored in an imaging device or a digital device typified by a digital camera with a printer, the image is temporarily stored in a host terminal such as a personal computer, and then the application on the host terminal is used to print the image It was necessary to transfer print data to the printer via the driver.

  On the other hand, recently, a so-called photo direct printer has been developed in which an image processing function is installed in a printer so that a digital device and the printer can be directly connected and printing can be performed without using a host terminal. For example, a digital camera and a photo direct printer are connected by a wired connection such as a USB, and an image stored in a memory card of the digital camera can be printed. It is also possible to directly mount a memory card on a photo direct printer and print an image stored on the memory card.

In such a photo direct printer, those that have a so-called index printing function that prints all the images stored on the memory card after reducing and aligning them, check the images with the index and select only the desired images Can be printed. Furthermore, in a photo direct printer equipped with a viewer that displays images stored on a memory card, it is possible to select and print only a desired image by checking the image with the viewer without performing index printing. .
JP 2000-059612 A

  By the way, the CPU mounted on the photo direct printer is not high in processing capacity like the CPU mounted on the personal computer. Inevitably, it takes some time for the decoding process.

  The problem here is when index printing is performed. That is, in the case of index printing, it is necessary to decode and generate a reduced image that is an index image for each image. Therefore, even if simple calculation is performed, “time required for decoding + required for reduction processing” It takes time as long as “time” × the number of index images, and the operator waits for a long time.

  There is also a problem when using a viewer. Since the viewer is used to confirm whether or not the image is to be printed, it does not require high display capability (resolution) and is equal to or less than the number of pixels of the image when the index image is printed. Therefore, in this case as well, decoding processing and reduction processing are involved, but from the user's point of view, in order to search for the target image, the reduced images are sequentially displayed as if turning the page. However, at present, the only way to perform such a high-speed response is to install a processor having a high processing capacity.

  The present invention has been made in view of such problems, and performs high-speed decoding and reduction processing of an image necessary for display on a display for index printing and selection of images to be printed. It is intended to provide technology.

In order to achieve the above object, for example, a print control apparatus of the present invention comprises the following arrangement. That is,
A print control apparatus for causing the printing of images by decoding the encoded encoding image data, supplied to the printing means in a predetermined pixel block size,
When a reduction ratio when printing the encoded image data is smaller than a predetermined magnification, an extraction method for extracting a pixel block at random from a plurality of pixel blocks is set, and when the reduction ratio is larger than a predetermined magnification, and configuration means for setting an extraction method for extracting a periodic pixel blocks from the plurality of pixel blocks,
In the set extraction method by the setting means, an extraction means for extracting the coded picture containing the block data,
Decoding means for decoding the pixel block extracted by the extraction means;
Reduction means for generating pixel data of a reduced image using the pixel block decoded by the decoding means.

  According to the present invention, display processing for confirming a compression-coded image to be printed stored in a storage medium and index print processing for printing a plurality of reduced images on one recording medium are performed at high speed. Makes it possible to do.

  Another object of the present invention is to provide a technology that enables selection of print quality or higher printing speed depending on the purpose and situation.

  Embodiments according to the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a block diagram mainly showing a photo direct printer according to the present embodiment. This photo direct printer not only operates as a normal PC printer that prints print data transferred from a host terminal such as a personal computer (PC), but also stores it in a digital camera, memory card, etc. by having an image processing function It is possible to print a JPEG image encoded in a predetermined format, for example, the JPEG method, without going through a host terminal.

  A configuration of a main part related to control of the photo direct printer will be described. Reference numeral 1000 denotes a control board. Reference numeral 1001 denotes an ASIC (Application Specific Integrated Circuits). The ASIC 1001 includes an interface unit of each unit and a CPU for generating print data and the like. Reference numeral 1002 denotes a connector for connecting the operation panel 1003. The user can use the operation panel 1003 to set and maintain various print setting information, browse and specify JPEG images in the memory card, specify print start, cancel print, and the like. Reference numeral 1004 denotes a connector for connecting the operation panel 1003 and a viewer (for example, a liquid crystal display) 1005. A viewer 1005 performs browsing of JPEG images recorded in the memory card 1007, menu display using a GUI, display of various error messages, and the like. Reference numeral 1006 denotes a connector for connecting the memory card 1007, which can directly read and print a JPEG image from the memory card 1007.

  Reference numeral 1008 denotes a USB (Universal Serial Bus) bus connector as a port for connecting the digital camera 1010. Reference numeral 1009 denotes a terminal for connecting the digital camera 1010, and reference numeral 1010 denotes a digital camera. The digital camera 1010 is configured to output a JPEG image and print setting information stored in an internal memory to a photo direct printer. Note that as the configuration of the digital camera 1010, various configurations such as a configuration having a memory as a storage unit inside and a configuration having a slot for mounting a removable memory can be employed. As a result, the JPEG image in the digital camera 1010 can be processed according to the print setting information set by the digital camera and can be directly printed by the camera.

  Reference numeral 1011 denotes a USB bus hub that passes through data from the PC 1013 when printing is performed based on print data from the PC 1013 which is a general-purpose information processing apparatus such as a personal computer connected via the connection connector 1012. Reference numeral 1014 denotes a memory, which is a control program for the CPU of the ASIC 1001, and image processing programs such as JPEG image decoding and reduction processing, conversion from luminance signal (RGB) to density signal (CMYK), scaling, gamma conversion, and error diffusion. It is used as a RAM area for storing a program memory for storing and a program for execution.

  Reference numeral 1015 denotes a connector for connecting the printer engine 1016. The printer engine 1016 is equipped with an inkjet printer engine that prints a color image using a plurality of color inks. Reference numeral 1017 denotes an LF (line feed) motor driver, and 1018 denotes a connector for connecting the KF motor 1019. Similarly, reference numeral 1020 denotes an ASF (Auto Sheet Feed) motor driver, and 1021 denotes a connector for connecting the ASF motor 1022. The LF motor is also used for scanning movement of the recording head by switching a clutch (not shown). Reference numeral 1023 denotes a power connector which inputs a DC voltage converted from commercial AC by a power source 1024.

  First, a case where the photo direct printer operates as a PC printer will be described. When print data is input from the PC 1013 via the connector 1012, it is sent directly to the printer engine 1016 via the USB hub 1011. The print data from the PC 1013 is interpreted, and character codes are bitmapped as necessary. Printing is performed based on the above.

  Next, a case where printing is performed while connected to a digital camera will be described. The photo direct printer and the digital camera 1010 are connected via a USB bus connector 1008. When a print request is made from the digital camera 1010, the image processing function performs JPEG image decoding, reduction processing, conversion from luminance signal (RGB) to density signal (CMYK), scaling, gamma conversion, error diffusion, etc. Print data that can be printed by the printer engine 1016 is generated. Printing is performed by sending the generated print data to the printer engine 1016.

  Finally, a case where printing is performed from a memory card will be described. The photo direct printer and the memory card are connected via a connector 1006 for connection. When a print request is made from the operation panel 1003, the image processing function performs JPEG image decoding, reduction processing, conversion from luminance signal (RGB) to density signal (CMYK), scaling, gamma conversion, error diffusion, etc. Print data that can be printed by the printer engine 1016 is generated. Printing is performed by sending the generated print data to the printer engine 1016. There are two types of print modes using a memory card, one is an index print mode, and the other is a mode for specifying and printing individual images.

  FIG. 2 is a view for explaining index printing of the photo direct printer according to the embodiment. Reference numeral 2000 denotes an index output by index printing, and all JPEG images stored in the memory card are reduced and aligned and printed. Reference numeral 2001 denotes a printing rectangle per image. There are as many print rectangular areas 2001 as the number of JPEG images stored in the memory card. However, in the illustrated case, it is shown that up to 8 × 4 index images are possible. Therefore, when 32 or more images exist on the memory card, the second sheet is printed.

  FIG. 3 is a diagram illustrating details of index printing of the photo direct printer according to the embodiment. In the print rectangular area 2001, an image print area 3000, an image number 3001, and a date 3002 are printed. An image area 3000 is a JPEG image that has been subjected to image processing such as decoding and reduction processing by the image processing function. An image number 3001 is a serial number assigned in the device. A date 3002 is a date when the JPEG image is created or updated. Therefore, when the memory card connected to the printer apparatus is taken out from the digital camera, the date indicates the shooting date and time.

  FIG. 4 is a diagram for explaining a viewer installed in the photo direct printer according to the present embodiment. The viewer 1005 displays the currently selected image area 4000, the image number 4001, and the date 4002, which are exactly the same as the layout shown in FIG.

  An image area 4000 is a JPEG image that has been decoded and reduced by the image processing function. An image number 4001 is a serial number assigned in the device. The date 4002 is the date when the JPEG image was created or updated. Selection of a JPEG image to be displayed on the viewer 1005 is performed using the operation panel 1003.

  The user can check all the JPEG images stored in the memory card without the host terminal by using the index 2002 and the viewer 1005 obtained by performing index printing. Also, a desired JPEG image can be selected from the JPEG images printed and displayed on the index 2000 or the viewer 1005 and printed. Furthermore, since the date when the JPEG image was taken can be confirmed, it is possible to select and print only the JPEG image of a specific date.

  FIG. 5 is a flowchart showing decoding of a JPEG image. In step S11, entropy decoding is performed to obtain 64 frequency components of a one-dimensional array. In step S12, a reverse zigzag sequence is performed to convert the one-dimensional array into a two-dimensional array frequency component. In step S13, inverse quantization is performed on the frequency components of the two-dimensional array. Finally, in step S14, inverse DCT transformation is performed on the frequency components that have been inversely quantized to obtain a pixel value of 8 × 8 pixels. By performing this process for all blocks (hereinafter referred to as MCU), the decoding of the JPEG image is completed.

  Next, reduction processing performed by the image processing function of the photo direct printer according to the present embodiment will be described. As an example, consider a case where an image of 2560 × 1920 pixels is reduced to 160 × 120 pixels. In this case, both horizontal and vertical can be reduced to 1/16. Since one MCU has a size of 8 × 8 pixels, one pixel in one MCU in two MCUs may be generated both horizontally and vertically. That is, it is understood that one pixel is generated from four 2 × 2 MCUs, that is, 16 × 16 pixels. Therefore, as shown in FIG. 6, one MCU is extracted from four MCUs, and only the extracted MCU is decoded. At this stage, the reduction ratio is ½. Next, the 8 × 8 pixels obtained by decoding are reduced at a reduction ratio of 1/8 by a general scaling method such as a bilinear method, and finally reduced to 1/16. In this way, instead of performing the reduction process after decoding all the MCUs, one MCU is extracted from a plurality of MCUs, and only the extracted MCUs are decoded and then the reduction process is performed. And reduction processing can be performed.

  In addition, the number of pixels of the image sensor (CCD) of recent digital cameras is increasing, but in many digital cameras, it is possible to select how many resolutions (the number of pixels of the captured image) are taken when taking an image. It has become. That is, the number of pixels constituting the captured image is not always fixed. On the other hand, since the image size at the time of index printing is fixed, the reduction ratio varies according to individual images. This means that the interval between unused MCUs when reducing the size varies depending on the size (number of pixels) of the original image.

  7, 8, and 9 are diagrams illustrating an MCU extraction method performed by the image processing function of the photo direct printer according to the present embodiment.

  FIG. 7 is a diagram for explaining a method of extracting one MCU from a fixed position from a plurality of MCUs (hereinafter referred to as MCU blocks). In the figure, the upper left MCU, that is, each of MCUs 1, 3, 5, 13, 15, 17, 25, 27, and 29 is always extracted from an MCU block composed of 2 × 2 MCUs. Since the logic for extracting the MCU from this fixed position is simple, the MCU extraction process can be performed at high speed. However, since the positions of MCUs to be extracted are always the same, if there are lines in MCUs that are not to be extracted, the data may be lost.

  FIG. 8 is a diagram for explaining a method of periodically extracting one MCU from an MCU block. In the figure, the upper left MCU is always extracted in odd-numbered rows of the MCU block, and the upper right MCU is always extracted in even-numbered rows. This method of periodically extracting MCUs requires different MCU positions for extraction from MCU blocks because the MCU positions to be extracted are different from each other, and MCU extraction processing is required compared to the method for extracting MCUs from fixed positions. Although it takes some time, it is possible to prevent data such as ruled lines from being lost because the position of the MCU to be extracted and the same phase of each MCU block are changed periodically.

  FIG. 9 is a diagram for explaining a method of randomly extracting one MCU from an MCU block. In the figure, when one MCU is extracted from an MCU block composed of four MCUs, a random number is generated and the MCU is extracted according to the random number. This method of selecting an MCU at random causes a heavy load on the process of generating a random number and takes a long time for the MCU selection process. However, since the position of the MCU to be extracted is randomly changed, data such as ruled lines is lost. Can be prevented, and a uniform reproduction can be obtained in terms of concentration. In FIG. 8, if there is a horizontal line in an MCU that is not subject to extraction, the loss is unavoidable, but in the case of FIG. 9, the position of the MCU to be extracted varies randomly, so the rate at which such a problem occurs is shown. It can also be lowered.

  FIG. 10 is a flowchart showing a series of operations of decoding and reduction processing performed by the image processing function of the photo direct printer according to the present embodiment. In step S21, one of the above MCU extraction methods is set. In step S22, entropy decoding is performed to obtain 64 frequency components of a one-dimensional array. In step S23, it is determined according to the previously set MCU extraction method whether these 64 frequency components are processing target MCUs. If it is determined that it is not a processing target MCU, the processing from step S24 to step S27 is not performed. If it is determined that it is a processing target MCU, an inverse zigzag sequence is performed in step S24 to convert the frequency component of the one-dimensional array into a two-dimensional array, and inverse quantization is performed in step S25. Further, in step S26, the inverse DCT transform is performed on the inversely quantized frequency component, thereby completing the decoding process. Finally, in step S27, reduction processing is performed on the 8 × 8 pixels obtained by decoding, and the image is reduced to the target reduction rate. This decoding and reduction process is performed until it is determined in step S28 that all the MCUs have been processed.

  FIG. 11, FIG. 12, and FIG. 13 are flowcharts relating to setting of the MCU extraction method performed by the image processing function of the photo direct printer according to the present embodiment.

  FIG. 11 is a flowchart regarding setting of an MCU extraction method in a photo direct printer having an index printing function and equipped with a viewer. In step S31, it is determined whether the decoding and reduction processing for viewer display is performed. If it is determined for the viewer display, a method for extracting the MCU from the fixed position is set in step S32. On the other hand, if it is determined that the decoding and reduction processing is not for viewer display, that is, index printing, a method of periodically extracting MCUs is set in step S33.

  At this time, the MCU extraction method is determined by decoding and reduction processing for viewer display or decoding and reduction processing for index printing. In the viewer display, a processing speed is required, but it is only necessary to confirm whether the image is an image to be printed. Therefore, a method of extracting the MCU from a fixed position with the fastest processing speed (FIG. 7) is selected. On the other hand, since index printing is used not only for image confirmation but also for viewing, a technique (FIG. 8) for extracting MCUs periodically with a certain degree of image reproducibility is selected.

  In the above description, the method of extracting the MCU from a fixed position for viewer display and the method of extracting the MCU periodically for index printing are set. For example, the method of extracting the MCU periodically for viewer display ( Various settings are possible, such as setting a method (FIG. 9) for randomly extracting MCUs for index printing (FIG. 8).

  FIG. 12 is a flowchart relating to setting of an MCU extraction method in a photo direct printer having an index printing function and capable of setting the quality of index printing. Assume that the print quality that can be set at this time is “clean” and “standard”. In step S41, it is determined whether the print quality is “clean”. If it is determined as “beautiful”, a method of extracting MCUs at random is set in step S42. On the other hand, if it is determined that the print quality is not “clean”, that is, “standard”, a method of periodically extracting the MCU is set in step S43.

  At this time, the MCU extraction method is determined by the print quality. When “Premium” is selected for the print quality, it is considered that a beautiful image is required even if time is required. Therefore, a method for extracting the MCU at random with the highest image reproducibility is set. .

  In the above description, a method of extracting MCUs at random when “clean” is selected as the print quality and a method of extracting MCUs periodically when “standard” is selected are set. Various settings are possible, such as a method of extracting an MCU at random when “clean” is selected in, and a method of extracting an MCU from a fixed position when “standard” is selected.

  FIG. 13 is a flowchart regarding setting of an MCU extraction method in a photo direct printer having an index printing function. In step S51, it is determined whether the reduction ratio is smaller than 1 / N (N is a multiple of 8 and a preset value). If it is determined that the reduction ratio is smaller than 1 / N, a method of extracting MCUs at random is set in step S52. On the other hand, if it is determined that the reduction ratio is greater than 1 / N, a method for periodically extracting the MCU is set in step S53.

  At this time, the MCU extraction method is determined by the reduction ratio. A small reduction ratio means that there are many MCUs to be thinned out. Therefore, in order to improve the reproducibility of an image, it is necessary to select MCUs without bias. Therefore, when the reduction ratio is smaller than a certain value (1 / N), a method of selecting an MCU at random is set.

In the above description, a method of extracting MCUs at random when the reduction ratio is smaller than 1 / N, and a method of extracting MCUs periodically when it is larger than 1 / N are set. Various settings such as a method of extracting an MCU at random when it is smaller than / N and a method of extracting an MCU from a fixed position when it is larger than 1 / N are possible.
In the present embodiment, index printing and viewer display have been described as examples, but the present invention is not limited to these. For example, the present invention can be applied to layout printing in which a plurality of images are laid out and printed on a single sheet.

  The above explanation is processing when the memory card MC 1007 is inserted into the printer apparatus and the index print of the memory card 1007 is instructed by the operation panel. However, the digital camera is connected to the printer and owned by the digital camera. The same applies when index printing of images in the memory card to be performed. In this case, the image is transferred from the digital camera at the timing of printing the index image of each image, and when it is received, the MCU to be decoded is selected and printed.

<Second Embodiment>
In the above embodiment (first embodiment), an example has been described in which the index image size is 160 × 120, and the reduction ratio is 1 / N (N is a multiple of 8) when the image is generated. For example, if N = 24, one of the 3 × 3 9 MCUs is selected and decoded, and as a result, one pixel of the index image is generated, so that the remaining 8 MCU blocks Is not subject to decryption.

  However, the captured original image may not be an integer multiple of 8 (the number of pixels on one side when DCT conversion is performed), or images with different resolutions may be mixed. For example, in recent digital cameras, a camera equipped with a CCD that can capture images with millions of pixels is usually used, but it is also possible to select a desired resolution from several levels of resolution and take an image. You can understand that.

  In order to simplify the description, also in the second embodiment, each index image size when printing the index image shown in FIG. 2 will be described as a pixel size of 160 × 120 as in the above embodiment. I will do it.

  Assume that the target image to be index printed is 3200 × 2400 pixels. In order to generate an index image of 160 × 120 pixels from this image, both horizontal and vertical must be reduced to 1/20. That is, it is necessary to generate one pixel at intervals of 20 pixels in both the horizontal and vertical directions of the original image.

  On the other hand, since this image is also encoded by DCT conversion with an MCU size of 8 × 8 pixels, when the width (height) of one MCU is “1”, both horizontal and vertical are 2 One pixel is generated at intervals of .5 (= 20/8) MCUs.

  Therefore, an example in which one pixel is generated from an MCU block composed of {floor (P) +1} × {floor (P) +1} based on the MCU interval P (P = 2.5 in this example). Will be described as a second embodiment. Here, floor (X) is a value that returns the maximum integer lower than the value X.

  In the case of P = 2.5, in the above case, 3 × 3, that is, the MCU block is composed of nine MCUs.

  In order to simplify the description, a description will be given with reference to FIG.

  In the figure, M (y, x) represents an MCU and corresponds to encoded data of 8 × 8 pixels.

  Then, variables x and y that specify the reference MCU are set to 0 as initial values. It is assumed that x and y can take a decimal point, and the integer part is used as information for specifying the MCU.

  Since x = y = 0 at the initial stage, the reference MCU is M (0, 0). Then, nine MCU blocks M (0,0), (0,1), (0,2), (1) including {INT (P) +1} × {INT (P) +1} = 3 × 3 , 0), (1,1), (1,2), (2,1), (2,2), (2,3). Then, one of the selected MCU blocks is decoded (the others are not to be decoded), and the first pixel of the index image is generated (if following FIG. 7, M (0,0) is to be decoded) Becomes).

  The variable x is then increased by 2.5. As a result, since x = 2.5, the reference MCU is M (0, 2), from which an MCU block composed of 9 3 × 3 MCUs is selected, and one of them is decoded. The second pixel is generated. Thereafter, when X is incremented by 2.5, one of the MCU blocks including the MCU indicated by the integer portion of X at that time is decoded to generate an output pixel. If the value of X exceeds the number of horizontal pixels of the original image / 8 ("8" is the size for DCT conversion), X is reset to 0 and Y is incremented by 2.5. Perform the following process.

  When the above processing is performed, a number of MCUs that are not decoded are generated as in the embodiment described above. That is, it is not necessary to decode all MCUs when generating an index image, and an index image can be generated at high speed.

  The above is the case where the size of the original image is 3200 × 2400 pixels. However, in the case of an image having a number of 2560 × 1920 pixels, it can be understood that the processing is equivalent to the embodiment described above. . Further, the present invention can be applied to the case where the original image has 1600 × 1200 pixels (P is 2 or less).

  As described above, according to the first and second embodiments, when performing index printing (printing a plurality of reduced images on one recording sheet), the decoding process can be minimized, The index print can be performed at high speed.

  Note that the various numerical values (DCT conversion target size, the number of pixels of each image, the number of pixels of the index image) shown in the embodiment are examples for facilitating understanding of the present invention. The invention is not limited.

It is a block diagram which shows the structure of the principal part in connection with control of a photo direct printer. It is a figure explaining the index printing of a photo direct printer. It is a figure explaining the detail of the index printing of a photo direct printer. It is a figure explaining the viewer mounted in the photo direct printer. It is a flowchart which shows the decoding of a JPEG image. It is a figure explaining the reduction process performed with the image processing function of a photo direct printer. It is a figure explaining the method of extracting one MCU from a fixed position from a MCU block. It is a figure explaining the method of extracting one MCU periodically from a MCU block. It is a figure explaining the method of extracting one MCU from an MCU block at random. It is a flowchart which shows a series of operation | movement of a decoding and reduction process performed with the image processing function of a photodirect printer. It is a flowchart regarding the MCU extraction method in the photo direct printer which has an index printing function and is equipped with a viewer. It is a flowchart regarding the MCU extraction method in the photo direct printer which has an index printing function and can set the quality of index printing. It is a flowchart regarding the MCU extraction method in the photo direct printer which has an index printing function. It is a figure for demonstrating the MCU extraction process in 2nd Embodiment.

Claims (4)

A print control apparatus for causing the printing of images by decoding the encoded encoding image data, supplied to the printing means in a predetermined pixel block size,
When a reduction ratio when printing the encoded image data is smaller than a predetermined magnification, an extraction method for extracting a pixel block at random from a plurality of pixel blocks is set, and when the reduction ratio is larger than a predetermined magnification, and configuration means for setting an extraction method for extracting a periodic pixel blocks from the plurality of pixel blocks,
In the set extraction method by the setting means, an extraction means for extracting the coded picture containing the block data,
Decoding means for decoding the pixel block extracted by the extraction means;
A printing control apparatus comprising: a reduction unit that generates pixel data of a reduced image using the pixel block decoded by the decoding unit. The encoded image data is stored in a storage medium,
The print control apparatus according to claim 1 , wherein the storage medium is a removable memory card directly connected to the print control apparatus. The encoded image data is stored in a storage medium,
The print control apparatus according to claim 1 , wherein the storage medium is a memory card included in an imaging apparatus directly connected to the print control apparatus, and receives image data by communicating with the imaging apparatus. . A control method for a printing control apparatus to perform printing of images by decoding the encoded encoding image data in a predetermined pixel block size, fed to the printing unit,
When a reduction ratio when printing the encoded image data is smaller than a predetermined magnification, an extraction method for extracting a pixel block at random from a plurality of pixel blocks is set, and when the reduction ratio is larger than a predetermined magnification, and setting step of setting an extraction method for extracting a periodic pixel blocks from the plurality of pixel blocks,
In the set extraction method with the setting step, an extraction step of extracting the coded picture containing the block data,
A decoding step of decoding the pixel block extracted by the extraction step;
A reduction step of generating pixel data of a reduced image using the pixel block decoded by the decoding step. A control method for a print control apparatus, comprising:

Images