Image signal reproduction device

• US 6,335,760 B1
• Filed: 03/24/1998
• Issued: 01/01/2002
• Est. Priority Date: 03/27/1997
• Status: Expired due to Term

• Current Assignee: PENTAX RICOH IMAGING COMPANY, LTD.
• Original Assignee: Asahi Kogaku Kogyo Kabushiki Kaisha
• Inventors: Sato, Koichi
• Primary Examiner(s): Kelley, Chris
• Assistant Examiner(s): PHILIPPE, GIMS S
• Application Number:
  US09/046,560
• Time in Patent Office: 1,379 Days
• Field of Search: 386/109, 386/27, 386/405, 386/412, 386/409, 386/219, 386/322, 386/396, 386/112, 386/124, 348/397, 348/390, 348/405, 348/412, 348/409, 348/219, 348/322, 348/396, 348/124, 348/441, 348/443, 348/458, 348/554, 348/552, 358/300, 358/447, 345/132, 367/108, 382/240
• US Class Current: 348/397.1
• CPC Class Codes: G09G 2340/02 Handling of images in compressed format, e.g. JPEG, MPEG
• CPC Class Codes: G09G 2340/0407 Resolution change, inclusive of the use of different resolutions for different screen areas
• CPC Class Codes: G09G 2370/045 using multiple communication channels, e.g. parallel and serial
• CPC Class Codes: G09G 5/005 Adapting incoming signals to the display format of the display terminal
• CPC Class Codes: G09G 5/006 Details of the interface to the display terminal specific for a display terminal using a CRT G09G1/167; using a flat panel G09G3/2096; circuits for interfacing with colour displays G09G5/04
• CPC Class Codes: G09G 5/391 Resolution modifying circuits, e.g. variable screen formats

Abstract

An image signal reproduction device, provided in an electronic still camera, comprises a CPU, an image signal processing circuit, a memory card, in which a compressed image signal is recorded, and a display device having a liquid crystal display (LCD) and a resolution recognition unit. A clock pulse, outputted from the CPU, is received by the resolution recognition unit, so that a recognition pulse, corresponding to the inherent resolution of the LCD, is outputted from the resolution recognition unit to the image signal processing circuit. The compressed image signal is read from the memory card, and reproduced to some extent corresponding to the resolution of the LCD.

Claims

1. An image signal reproduction device connectible to a plurality of displays, said image signal reproduction device comprising:

an image signal expansion processor for expanding a compressed image signal from a lower resolution to a higher resolution of said image, said image signal expansion processor converting said compressed image signal to a decompressed image signal;

a display connection through which an inherent resolution of a display connectible to the display connection is transmitted from the display to the image signal reproduction device, a plurality of different inherent resolutions being capable of being transmitted via said display connection;

a resolution setting processor that checks the display connection and sets a predetermined resolution lower than or equal to the transmitted inherent resolution; and

an image signal reproduction circuit that controls said image signal expansion processor to expand said compressed image signal until a decompression corresponding to said predetermined resolution is reached and reproduces said image at said predetermined resolution so that each display connectible to the display connection, when connected thereto, displays said image at a predetermined resolution lower than or equal to the connected display'"'"'s inherent resolution.

2. An image signal reproduction device according to claim 1, wherein said compressed image signal is obtained by processing original image data with a discrete cosine transformation, so that the original image data are broken down into spatial frequency components which are DCT coefficients, quantizing said DCT coefficients to generate quantized DCT coefficients, dividing said quantized DCT coefficients into a plurality of groups, and encoding said quantized DCT coefficients for each of said groups.

3. An image signal reproduction device according to claim 2, where in said image signal expansion processor expands said compressed image signal for each of said groups, in such a manner that images are reproduced successively from a low resolution image to a high resolution image.

4. An image signal reproduction device according to claim 1, wherein said display comprises an information output processor outputting information indicating said inherent resolution, and said resolution setting processor recognizes said inherent resolution in accordance with said information transmitted through the display connection.

5. An image signal reproduction device according to claim 4, wherein said resolution setting processor outputs a clock pulse of a constant period, and said information output processor outputs said information in association with said clock pulse.

6. An image signal reproduction device according to claim 1, wherein said display is connected to an electronic camera.

7. An image signal reproduction device connectible to a plurality of displays, said image signal reproduction device comprising:

an image signal expansion processor for expanding a compressed image signal from a lower resolution to a higher resolution of said image, said image signal expansion processor converting said compressed image signal to a decompressed image signal;

a display connection through which a maximum displayable resolution of a display connectible to the display connection is transmitted from the display to the image signal reproduction device, a plurality of different maximum displayable resolutions being capable of being transmitted via said display connection;

a resolution setting processor that checks the display connection and incrementally sets a predetermined resolution lower than or equal to the transmitted maximum displayable resolution; and

an image signal reproduction circuit that controls said image signal expansion processor to expand said compressed image signal until a decompression corresponding to said predetermined resolution is reached and reproduces said image at said predetermined resolution so that each display connectible to the display connection, when connected thereto, displays said image at a predetermined resolution lower than or equal to the connected display'"'"'s maximum displayable resolution.

8. An image signal reproduction device connectible to a plurality of displays, said image signal reproduction device comprising:

an image signal expansion processor for expanding a compressed image signal from a coarser gradation to a finer gradation of said image, said image signal expansion processor converting said compressed image signal to a decompressed image signal;

a display connection through which an inherent gradation of a display connectible to the display connection is transmitted from the display to the image signal reproduction device, a plurality of different inherent gradations being capable of being transmitted via said display connection;

a gradation setting processor that checks the display connection and sets a predetermined gradation coarser than or equal to the transmitted inherent gradation; and

an image signal reproduction circuit that stops said expansion by said image signal expansion processor at a step corresponding to said predetermined gradation and reproduces said image at said predetermined gradation so that each display connectible to the display connection, when connected thereto, displays said image at a predetermined gradation coarser than or equal to the connected display'"'"'s inherent gradation.

9. An image signal reproduction device according to claim 8, wherein said compressed image signal is obtained by processing original image data with a discrete cosine transformation, so that the original image data are broken down into spatial frequency components which are DCT coefficients, quantizing said DCT coefficients to generate quantized DCT coefficients, dividing said quantized DCT coefficients into a plurality of groups, and encoding said quantized DCT coefficients for each of said groups.

10. An image signal reproduction device according to claim 9, wherein said image expansion processor expands said compressed image signal for each of said groups, in such a manner that images are reproduced successively from a crude gradation image to a fine gradation image.

11. An image signal reproduction device according to claim 8, wherein said display comprises an information output processor outputting information indicating said inherent gradation, and said gradation setting processor recognizes said inherent gradation in accordance with said information.

12. An image signal reproduction device according to claim 11, wherein said gradation setting processor outputs a clock pulse of a constant period, and said information output processor outputs said information in association with said clock pulse.

13. An image signal reproduction device according to claim 11, wherein said display is connected to an electronic camera.

14. An image signal reproduction device connectible to a plurality of displays, said image signal reproduction device comprising:

an image signal expansion processor for expanding a compressed image signal from a coarser gradation to a finer gradation of said image, said image signal expansion processor converting said compressed image signal to a decompressed image signal;

a display connection through which a maximum displayable gradation of a display connectible to the display connection is transmitted from the display to the image signal reproduction device, a plurality of different maximum displayable gradations being capable of being transmitted via said display connection;

a gradation setting processor that checks the display connection and incrementally sets a predetermined gradation coarser than or equal to the transmitted maximum displayable gradation; and

an image signal reproduction circuit that stops said expansion by said image signal expansion processor at a step corresponding to said predetermined gradation and reproduces said image at said predetermined gradation so that each display connectible to the display connection, when connected thereto, displays said image at a predetermined gradation coarser than or equal to the connected display'"'"'s maximum displayable gradation.

15. An image signal reproduction system comprising:

a display indicating an image, which is obtained by expanding a compressed image signal, said display including a resolution information outputting processor outputting resolution information which corresponds to resolutions which said display is capable of displaying; and

an image signal reproduction device, comprising;

a display connection through which said resolution information is transmitted from the resolution information outputting processor of the display to the image signal reproduction device, a plurality of different resolutions being capable of being transmitted via said resolution information via said display connection;

a resolution selecting processor that checks the display connection and selects one of said resolutions based on said resolution information output by said resolution information outputting processor and transmitted through the display connection;

an image signal expansion processor expanding said compressed image signal, said image signal expansion processor changing the amount of said compressed image signal to be expanded in accordance with the selected resolution by expanding said compressed image signals from a lower resolution to a higher resolution of said image, said image signal expansion processor converting said compressed image signal to a decompressed image signal; and

an image signal reproduction circuit that controls said image signal expansion processor to expand said compressed image signal until a decompression corresponding to said selected resolution is reached and reproduces said image at said selected resolution so that the display connected to the display connection displays said image at the selected resolution selected from said resolution information, transmitted through said display connection, which corresponds to said resolutions which said display is capable of displaying.

16. An image signal reproducing device according to claim 15, wherein said image signal expansion processor comprises:

a first image processor generating a reproduced image signal, said first image processor dividing said compressed image signal, which has been obtained by orthogonally-converting a first image signal and arranging the orthogonally-converted image signal in an order depending on spatial frequency, into a plurality of groups from a lower spatial frequency to a higher spatial frequency, and expanding said compressed image signal contained in said groups while changing a number of said groups in accordance with said resolution of said image which can be indicated by said display, so that said reproduced image signal is generated; and

a second image processor generating a final image signal, said second image processor thinning a predetermined number of pixels, in accordance with said resolution of said image which can be indicated by said display, from said reproduced image signal, to generate said final image signal, which is indicated by said display.

17. An image signal reproducing device according to claim 16, wherein said first image processor performs an expansion process sequentially from a group corresponding to said lower spatial frequency to a group corresponding to said higher spatial frequency, and, as a resolution of said display decreases, changes the group to which said expansion is performed to the other group corresponding to a lower spatial frequency and decreases the number of said groups to which said expansion is performed.

18. An image signal reproduction system comprising:

a display indicating an image, which is obtained by expanding a compressed image signal, said display including a gradation information outputting processor outputting gradation information which corresponds to gradations which said display is capable of displaying; and

an image signal reproduction device, comprising;

a display connection through which said gradations information is transmitted from the gradation information outputting processor in the display to the image signal reproduction device, a plurality of different gradations being capable of being transmitted via said gradation information via said display connection;

a gradation selecting processor that checks the display connection and selects one of said gradations based on said gradation information output by said gradation information outputting processor and transmitted through the display connection;

an image signal expansion processor expanding said compressed image signal, said image signal expansion processor changing the amount of said compressed image signal to be expanded in accordance with the selected gradation by expanding said compressed image signals from a coarser gradation to a finer gradation of said image, said image signal expansion processor converting said compressed image signal to a decompressed image signal; and

an image signal reproduction circuit that stops said expansion by said image signal expansion processor at a decompression corresponding to said selected gradation and reproduces said image at said selected gradation so that the display connected to the display connection displays said image at the selected gradation selected from said gradation information, transmitted through said display connection, which corresponds to said gradations which said display is capable of displaying.

19. An image signal reproducing device according to claim 18, wherein said image signal expansion processor comprises:

a first image processor generating a reproduced image signal, said first image processor dividing said compressed image signal, which has been obtained by orthogonally-converting a first image signal and arranging the orthogonally-converted image signal in an order depending on spatial frequency, into a plurality of groups from a lower spatial frequency to a higher spatial frequency, and expanding said compressed image signal contained in said groups while changing a number of said groups in accordance with said gradation of said image which can be indicated by said display, so that said reproduced image signal is generated; and

a second image processor generating a final image signal, said second image processor thinning a predetermined number of luminance bits per pixel, in accordance with said gradation of said image which can be indicated by said display, from said reproduced image signal, to generate said final image signal, which is indicated by said display.

20. An image signal reproducing device according to claim 19, wherein said first image processor performs an expansion process sequentially from a group corresponding to said lower spatial frequency to a group corresponding to said higher spatial frequency, and, as a gradation of said display decreases, changes the group to which said expansion is performed to the other group corresponding to a lower spatial frequency and decreases the number of said groups to which said expansion is performed.

21. An image signal reproduction system comprising:

a memory storing a compressed image as a plurality of scans arranged from a lower spatial frequency to a higher spatial frequency, said image having a predetermined image resolution;

a display device outputting at least one predetermined display resolution that said display is capable of displaying and that is less than said predetermined image resolution; and

an image signal reproduction device comprising;

a display connection through which the at least one predetermined display resolution, output by the display device, is transmitted from the display device to the image signal reproduction device;

a resolution setting processor that checks the display device and receives said at least one predetermined display resolution output from the display device, said resolution setting processor being capable of checking and receiving a plurality of different display resolutions from the display device;

an image signal expansion processor that reads said at least one predetermined display resolution of said display device output by the display device and transmitted through the display connection and that expands said compressed image signal by expanding a number of scans at least one less than a total number of said plurality of scans, said expanded number of scans being sufficient to form an image of said at least one predetermined display resolution, said image signal expansion processor further converting said expanded number of scans into an image signal of said at least one predetermined display resolution and said display indicating said image signal at said at least one predetermined display resolution, so that the display connected to the display connection displays said image at the received at least one predetermined display resolution, transmitted to said resolution setting processor, that is less than said predetermined image resolution.

22. An image signal reproduction system comprising:

a memory storing a compressed image as a plurality of scans arranged from a lower spatial frequency to a higher spatial frequency, said image having a predetermined image gradation;

a display device outputting at least one predetermined display gradation that said display is capable of displaying and that is less than said predetermined image gradation; and

an image signal reproduction device comprising;

a display connection through which the at least one predetermined display gradation, output by the display device, is transmitted from the display device to the image signal reproduction device;

a resolution setting processor that checks the display device and receives said at least one predetermined display gradation output from the display device, said resolution setting processor being capable of checking and receiving a plurality of different display gradations;

an image signal expansion processor that reads said at least one predetermined display gradation of said display device output by the display device and transmitted through the display connection and that expands said compressed image signal by expanding a number of scans at least one less than a total number of said plurality of scans, said expanded number of scans being sufficient to form an image of said at least one predetermined display gradation, said image signal expansion processor further converting said expanded number of scans into an image signal of said at least one predetermined display gradation and said display indicating said image signal at said at least one predetermined display gradation, so that the display connected to the display connection displays said image at the received at least one predetermined display gradation, transmitted to said resolution setting processor, that is less than said predetermined image gradation.