Image data display system

• US 5,150,462 A
• Filed: 11/16/1989
• Issued: 09/22/1992
• Est. Priority Date: 06/27/1986
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Takeda, Haruo, Tabata, Kuniaki
• Primary Examiner(s): Harkcom, Gary V.
• Assistant Examiner(s): Nguyen, Phu K.
• Application Number:
  US07/437,706
• Time in Patent Office: 1,041 Days
• Field of Search: 364/518, 364/521, 340/747, 340/706, 340/750, 340/798, 340/799, 340/731, 395/162, 395/164, 395/166
• US Class Current: 345/555
• CPC Class Codes: G06F 16/51 Indexing; Data structures therefor; Storage structures
• CPC Class Codes: G09G 2340/02 Handling of images in compressed format, e.g. JPEG, MPEG
• CPC Class Codes: G09G 5/399 using two or more bit-mapped memories, the operations of which are switched in time, e.g. ping-pong buffers

Abstract

An image data display system includes a file unit for storing image data is compressed form, a display unit for displaying image data, a table for storing address information of a plurality of image data to be read from the file unit, a buffer memory having a memory area corresponding to at least two image frames for temporarily storing image data read from the file unit, an expansion processor for expanding image data in the buffer memory, a bit map memory for storing expanded image data, an output unit for outputting image data in the bit map memory to the display unit, an input unit for inputting a first command instructing a successive display of image data and a second command instructing a halt of the successive display, and a control unit responsive to the first command for switching in a predetermined order the buffer memory area used for storing image data read from the file unit and the buffer memory area used by the expansion processor and successively reading image data from the file unit while referring to the table, and responsive to the second command for halting the read operation of image data from the file unit, whereby a desired image frame successively displayed is rendered in a still state by the second command from the input unit.

Claims

1. An image data display system comprising:

a file unit for storing a plurality of variable length image data in compressed form;

a display unit having a display screen for displaying image data;

table means for storing address information of a plurality of image data to be read from said file unit;

a buffer memory having a plurality of memory areas corresponding to at least two image frames for temporarily storing compressed image data read out from said file unit;

means for expanding compressed image data read out from one of the memory areas of said buffer memory;

a bit map memory having at least two image frame memory regions for storing expanded image data to be displayed on said display screen;

means for outputting expanded image data in either one of said two image frame memory regions of said bit map memory to the display unit;

input means for inputting from a user a first command instructing a successive display of image data and a second command instructing a halt of the successive display; and

control means responsive to said first command for automatically switching between at least first and second memory areas of said plurality of memory areas and between said two image frame memory regions of said bit map memory in a predetermined order, respectively, such that said first memory area of said buffer memory is used for storing compressed image data read out from said file unit and said second memory area of said buffer memory and one of said at least two image frame memory regions of said bit map memory are used by the expanding means, and for successively reading out image data from said file unit to said first memory area by referring to said table means while said means for outputting expanded image data is displaying the contents of the other of said two image frame memory regions of said bit map memory on said display screen and said expanding means is processing compressed image data in said second memory area to write expanded image data into said one region of said bit map memory, and responsive to said second command for halting said automatic switching operation of the memory areas and frame memory regions and said successive reading operation of image data from said file unit,

whereby a desired image data on the display screen is rendered by said control means to stay on the display screen in response to the second command inputted by said user from said input means during when a plurality of frames of image data are successively displayed on the display screen.

2. An image data display system according to claim 1, wherein said control means switches said two memory regions of said bit map memory in synchronization with the completion of an expanding operation of each image data in said buffer memory and switches between said memory area of said buffer memory in synchronization with a later of the completion of said processing operation or the completion of a read operation of image data from said file unit performed in parallel with said processing operation.

3. An image data display system according to claim 1, further comprising means for designating a period of time to display each of images on said display screen, and said control means including means for switching said two memory regions of said bit map memory in accordance with a time interval corresponding to said designated period of time measured from the previous switching operation executed for said at least two memory regions if the processing operation of each image data in said buffer memory has been completed theretofore.

4. An image data display system according to claim 1, further comprising means for designating a period of time to display each of images on said display screen, and said control means including means for adjusting the timing of switching of said two memory regions of said bit map memory in accordance with said designated period of time.

5. An image data display system according to claim 1, further comprising means for designating a period of time to display each of images on said display screen, and said control means including means for adjusting the timing of switching of said two memory regions of said bit map memory and the timing of switching of the memory areas of said buffer memory in accordance with said designated period of time.

6. An image data display system comprising:

file means for storing a plurality of frames of variable length image data in compressed form;

access means for reading out one frame of image data from said file means in response to a read signal;

buffer memory means divided into at least two memory areas each of which has a memory capacity capable of storing one frame of compressed image data read out from said file means by said access means;

means for expanding image data stored in said buffer memory means;

bit map memory means having at least two frames of memory areas each for storing one frame of image data expanded by said expanding means;

means for displaying image data stored in either one of the memory areas of said bit map memory on a display screen; and

control means for automatically switching between a memory area of said buffer means to be used by said access means to store said image data and another memory area of said buffer memory means to be used by said expanding means, for switching between a memory area of said bit map memory means to be used by said display means and another memory area of said bit map memory means to be used by said expanding means to store an expanded image data and for providing access means with said read signal and said expanding means with a signal to start the operation of an image data expansion for a block of image data before the completion of a read operation of said access means while a frame of image data expanded already resides in said display screen.

7. An image data display system according to claim 6, wherein said control means switches between said memory areas of said buffer memory means when both the read operation of said access means and the expanding operation of said access means and the expanding operation of said expanding means are completed.

8. An image data displaying system according to claim 6, wherein said control means switches between said memory areas of said bit map memory means in synchronization with the completion of a expanding operation of said expanding means and switches between said memory areas of said buffer memory means in synchronization with the completion of a later one of said expanding operation and a read operation of said access means performed in parallel with said expanding operation.

9. An image data displaying system according to claim 6, wherein said bit map memory means has at least two memory areas;

and

said control means switches between said memory areas of said bit map memory means used by said displaying means in synchronization with the completion of an expanding operation of said expanding means.

10. An image data displaying system according to claim 6, further comprising means for designating a period of time to display each of images on said display screen, and said control means including means for adjusting the timing of switching of said two memory areas of said bit map memory means in accordance with said designated period of time.

11. An image data display system according to claim 6 further comprising means for designating a period of time to display each of images on said display screen, and said control means including means for adjusting the timing of switching of said two memory areas of said bit map memory means and the timing of switching of the memory areas of said buffer memory means in accordance with said designated period of time.

12. An image data retrieval system comprising:

file means for storing a plurality of pages of variable length image data in compressed form;

means for storing index records corresponding to said image data each of which has index information for retrieving one of said image data and address information for accessing said one image data;

buffer memory means divided into at least two memory areas each of which has a memory capacity capable of storing one page of image data of compressed image data read out from said file means;

means for expanding image data stored in said buffer memory means;

bit map memory means divided into at least two memory areas each for storing image data expanded by said expanding means;

means for displaying image data stored in said bit map memory means on a display screen;

input means for inputting, by user, index information to specify image data to be retrieved and operation commands one of which designates a mode of image data display on said display screen;

table means for storing address information of retrieval image data to be displayed on said display screen; and

control means including means for retrieving index records from said index storing means in accordance with index information of image data designated by the user through said input means to store retrieved index records in said table means, and means, responsive to an input command from said input means, for successively reading out a plurality of image data on the basis of address information included in said retrieved index records in said table means by automatically changing a memory area of said buffer memory means to be used to store said image data for every page and for successively operating said expanding means in parallel or simultaneously with said read out operation so as to expand image data which has already been read into one of said areas of said buffer memory means by automatically changing one of said at least two memory areas of said bit map memory means to be used to store one page of expanded image data and the other of said at least two memory areas of said bit map memory means to be accessed by said display means when said input command designates a successive display mode.

13. An image data retrieval system according to claim 12, wherein said control means comprises means responsive to an input command from said input means for reading out one page of image data on the basis of address information included in one of said retrieved index records stored in said table means by changing a memory area of said buffer memory means to be used to store said image data, for operating said expanding means so as to expand said one page of image data after said image data has been read into one of said areas of said buffer memory means by changing a memory area of said bit map memory means to bused to store one page of expanded image data and a memory area of said bit map memory means to be accessed by said display means and for waiting for a next command from said input means when said input command designates a display mode to advance the display operation step by step.

14. An image data retrieval system according to claim 12, further comprising means for designating a period of time to display each of images on said display screen, and said control means including means for adjusting the timing of switching of said two memory areas of said bit map memory means in accordance with said designated period of time.

15. An image data retrieval system according to claim 12, further comprising means for designating a period of time to display each of images on said display screen, and said control means including means for adjusting the timing of switching of said two memory areas of said bit map memory means in accordance with said designated period of time.

16. An image data retrieval system according to claim 12, further comprising means for designating a period of time to display each of images on said display screen, and said control means including means for adjusting the timing of switching of said two memory areas of said bit map memory means and the timing of switching of the memory areas of said buffer memory means in accordance with said designated period of time.