Gray-level image processing with weighting factors to reduce flicker

• US 5,663,772 A
• Filed: 03/27/1995
• Issued: 09/02/1997
• Est. Priority Date: 03/29/1994
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Aoki, Norio, Gotoh, Shoichi, Uehara, Hirotoshi
• Primary Examiner(s): Peng, John K.
• Assistant Examiner(s): GRANT, CHRISTOPHER C
• Application Number:
  US08/410,877
• Time in Patent Office: 890 Days
• Field of Search: 348/671, 348/672, 348/673, 348/675, 348/679, 348/683, 348/910, 348/571
• US Class Current: 348/671
• CPC Class Codes: G09G 2310/0224 Details of interlacing
• CPC Class Codes: G09G 2320/0247 Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
• CPC Class Codes: G09G 3/2007 Display of intermediate tones
• CPC Class Codes: G09G 5/28 for enhancement of character form, e.g. smoothing
• CPC Class Codes: H04N 5/445 for displaying additional information H04N5/50 takes precedence

Abstract

According to a method and a system of the present invention, a gray-level data is generated from a binary image while reducing the vertical brightness transition, and a display with a reduced flicker is enabled in an interlaced scanning system. A filtering operation is conducted with respect to each of the pixels in a dot matrix by using the data of each pixel and the dot matrix data of the pixel adjacent to the pixel in a vertical direction, thereby generating a gray-level data and writing the data into a frame memory. A display with a reduced flicker may be conducted by transforming the gray-level data into a predetermined set of colors consisting of a foreground color, a background color, and an intermediate color thereof.

Claims

1. A gray-level image display method for displaying an image represented by binary pixel data in multiple levels, comprising the steps of:

generating a gray-level pixel data by conducting an operation with respect to respective pixels of the binary pixel data by providing predetermined weighting factors for a data of a first pixel and for a data of a second pixel adjacent to the first pixel; and

displaying an image represented by the gray-level pixel data,

wherein the step of displaying the image represented by the gray-level pixel data comprises the steps of;

writing the gray-level pixel data into a frame memory;

mapping the gray-level pixel data read from the frame memory to a predetermined set of colors consisting of a foreground color, a background color and at least one intermediate color; and

displaying the gray-level pixel data on a display of an interlaced scanning system based on the mapped set of colors.

2. A gray-level image display method according to claim 1, wherein in the step of generating the gray-level pixel data, the first pixel and the second pixel are adjacent to each other in a direction perpendicular to a scan line of the interlaced scanning system.

3. A gray-level image display method according to claim 2, wherein the step of generating the gray-level pixel data comprises the steps of:

storing the data of the first pixel into a first memory region of a memory means; and

storing the data of the second pixel into the first memory region of the memory means, while storing the data of the first pixel to a second memory region of the memory means.

4. A gray-level image display method according to claim 1, wherein in the step of generating the gray-level pixel data, a plurality of pixels are adjacent to the first pixel;

one of the plurality of pixels is adjacent to the first pixel in a direction perpendicular to a scan line of the interlaced scanning system; and

the other of the plurality of pixels is adjacent to the first pixel in a direction parallel to the scan line.

5. A gray-level image display method according to claim 2, wherein the step of mapping the pixel data to the set of colors is a step of mapping the gray-level pixel data to the plural sets of colors.

6. A gray-level image display method according to claim 5, wherein the step of generating the gray-level pixel data comprises the steps of:

storing the data of the first pixel into a first memory region of a memory means; and

storing the data of the second pixel into the first memory region of the memory means, while storing the data of the first pixel to a second memory region of the memory means.

7. A gray-level image display method according to claim 4, wherein the mapping step is a step of mapping the gray-level pixel data to the plural sets of colors.

8. A gray-level image display method for displaying an image represented by binary pixel data in multiple levels, comprising the steps of:

generating a gray-level pixel data by conducting an operation with respect to respective pixels of the binary pixel data by providing predetermined weighting factors for a data of a first pixel and for a data of a second pixel adjacent to the first pixel; and

displaying an image represented by the gray-level pixel data,

wherein the step of displaying the image represented by the gray-level pixel data comprises the steps of;

mapping the gray-level pixel data to a predetermined sets of colors consisting of a foreground color, a background color and at least one intermediate color;

writing a color data representing the mapped set of colors into a frame memory; and

displaying the color data on a display of an interlaced scanning system.

9. A gray-level image display method for displaying an original image including a first pixel and a second pixel adjacent to the first pixel, the first pixel having a first binary pixel data, the second pixel having a second binary pixel data, comprising the steps of:

mapping the binary pixel data to a color data representing a predetermined background color and a predetermined foreground color;

generating a gray-level pixel data for the first pixel by conducting an operation with respect to a first color data of the first pixel and a second color data of the second pixel with predetermined weighting factors; and

displaying an image represented by the gray-level pixel data corresponding to the original image.

10. A gray-level image display apparatus for displaying an image represented by binary pixel data, comprising:

a generating means for generating a gray-level pixel data by conducting an operation with respect to respective pixels of the binary pixel data by providing predetermined weighting factors for a data of a first pixel and for a data of a second pixel adjacent to the first pixel; and

a display means for displaying an image represented by the gray-level pixel data,

wherein the display means for displaying the image represented by the gray-level pixel data comprises;

a writing means for writing the gray-level pixel data into a frame memory; and

a mapping means for mapping the gray-level pixel data read from the frame memory to a predetermined set of colors consisting of a foreground color, a background color and at least one intermediate color;

wherein the display means displays the gray-level pixel data on a display of an interlaced scanning system based on the mapped set of colors.

11. A gray-level image display apparatus according to claim 10, wherein the first pixel and the second pixel are adjacent to each other in a direction perpendicular to a scan line of the interlaced scanning system.

12. A gray-level image display apparatus according to claim 11, wherein the generating means for generating the gray-level pixel data comprises an FIFO (first-in first-out) type register for operation based on the data of the first pixel and the data of the second pixel.

13. A gray-level image display apparatus according to claim 10, wherein a plurality of pixels are adjacent to the first pixel;

one of the plurality of pixels is adjacent to the first pixel in a direction perpendicular to a scan line of the interlaced scanning system; and

the other of the plurality of pixels is adjacent to the first pixel in a direction parallel to the scan line.

14. A gray-level image display apparatus according to claim 11, wherein the mapping means maps the gray-level pixel data to the plural sets of colors.

15. A gray-level image display apparatus according to claim 14, wherein the generating means for generating the gray-level pixel data comprises an FIFO (first-in first-out) type register for operation based on the data of the first pixel and the data of the second pixel.

16. A gray-level image display apparatus according to claim 13, wherein the mapping means maps the gray-level pixel data to the plural sets of colors.

17. A gray-level image display apparatus for displaying an image represented by binary pixel data, comprising:

a generating means for generating a gray-level pixel data by conducting an operation with respect to respective pixels of the binary pixel data by providing predetermined weighting factors for a data of a first pixel and for a data of a second pixel adjacent to the first pixel; and

a display means for displaying an image represented by the gray-level pixel data,

wherein the display means for displaying the image represented by the gray-level pixel data comprises;

a mapping means for mapping the gray-level pixel data to a predetermined set of colors consisting of a foreground color, a background color and at least one intermediate color; and

a writing means for writing the color data representing the mapped set of colors into a frame memory;

wherein the display means displays the color data on a display of an interlaced scanning system.

18. A gray-level image display apparatus for displaying an original image including a first pixel and a second pixel adjacent to the first pixel, the first pixel having a first binary pixel data, the second pixel having a second binary pixel data, comprising:

a mapping means for mapping the binary pixel data to a color data representing a predetermined background color and a predetermined foreground color;

a generating means for generating a gray-level pixel data for the first pixel by conducting an operation with respect to a first color data of the first pixel and a second color data of the second pixel with predetermined weighting factors; and

a display means for displaying an image represented by the gray-level pixel data corresponding to the original image.

19. A gray-level image display method for displaying an original image including a first pixel and a second pixel adjacent to the first pixel, the first pixel having a first binary pixel data, the second pixel having a second binary pixel data, comprising the steps of:

generating a gray-level pixel data for the first pixel by conducting an operation with respect to the first binary pixel data of the first pixel and the second binary pixel data of the second pixel with predetermined weighting factors; and

displaying an image represented by the gray-level pixel data corresponding to the original image,

wherein the step of displaying the image represented by the gray-level pixel data corresponding to the original image comprises the steps of;

writing the gray-level pixel data into a frame memory;

mapping the gray-level pixel data read from the frame memory to a predetermined set of colors consisting of a foreground color, a background color and at least one intermediate color; and

displaying the gray-level pixel data on a display of an interlaced scanning system based on the mapped set of colors.

20. A gray-level image display apparatus for displaying an original image including a first pixel and a second pixel adjacent to the first pixel, the first pixel having a first binary pixel data, the second pixel having a second binary pixel data comprising:

a generating means for generating a gray-level pixel data for the first pixel by conducting an operation with respect to the first binary pixel data of the first pixel and the second binary pixel data of the second pixel with predetermined weighting factors; and

a display means for displaying an image represented by the gray-level pixel data corresponding to the original image,

wherein the display means for displaying the image represented by the gray-level pixel data corresponding to the original image comprises;

a writing means for writing the gray-level pixel data into a frame memory; and

a mapping means for mapping the gray-level pixel data read from the frame memory to a predetermined set of colors consisting of a foreground color, a background color and at least one intermediate color;

wherein the display means displays the gray-level pixel data on a display of an interlaced scanning system based on the mapped set of colors.