Method for displaying an image including characters and a background

• US 5,195,180 A
• Filed: 06/21/1989
• Issued: 03/16/1993
• Est. Priority Date: 06/23/1988
• Status: Expired due to Fees

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Takakura, Masaki, Yamane, Yasukuni, Kako, Noritoshi
• Primary Examiner(s): Harkcom, Gary V.
• Assistant Examiner(s): Nguyen, Phu K.
• Application Number:
  US07/369,125
• Time in Patent Office: 1,364 Days
• Field of Search: 364/518, 364/521, 364/200 MS File, 364/900 MS File, 340/747, 340/750, 340/703, 340/730, 395/141, 395/142, 395/143, 395/162, 395/164
• US Class Current: 715/729
• CPC Class Codes: G09G 5/00 Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators image data processing or generation, in general G06T
• CPC Class Codes: G09G 5/395 Arrangements specially adapted for transferring the contents of the bit-mapped memory to the screen G09G5/399 takes precedence

Abstract

In a method for displaying an image, the image is divided into a first image area which includes characters, the border of which is overlapping a part of a color background, and a second image area which includes the other part of the background. The method includes the steps of setting data of pixels of the image using n bits in a multi-purpose area of an image memory, in a manner that, in setting data of pixels in the first image area, some of the n bits are used for color information of the background present at the border of the characters and the others are used for data of the characters. Further, in setting data for pixels in the second image area, all of the n bits are used for color information of the background, except that of the part underlying the border of the characters. The method further includes the steps of setting a flag in another area of the image memory, the flag indicating to which of the first and second image area each of the pixels of the image belongs; synthesizing color information of the background and that of the characters based on the image data and the flag stored in the image memory so that colors of the characters at the border thereof are mixed with colors of the background so as to have neutral tints; and displaying the image, obtained through the synthesis, on a display unit.

Claims

1. A method for displaying an image, wherein the iamge is divided into a first iamge area including a character and a second image area including background, an image processing device for performing the method including a data setting device for setting image data corresponding to the character and the background, an image memory for storing the image data set by the setting device, a synthesizing device for synthesizing the image data of the character and the background, and a display unit for displaying the character synthesized with the background, comprising the steps of:

setting the image data corresponding to pixels of the image using a fixed number of bits in a first memory area of the image memory such that

(a) when a flag is set to a first value and stored in a second memory area of the image memory, predetermined ones of the fixed number of bits are used to represent color information of the background and predetermined remaining ones of the fixed number of bits are used to represent grey scale values of the character, and

(b) when the flag is set to a second value and stored in the second memory area of the image memory, all of the fixed number of bits are used to represent the color information of the background;

synthesizing color information of the character based on the color information of the background and the grey scale values of the character when the flag is set to the first value to thereby gradually deemphasize and blend the color information of the character into the color information of the background; and

displaying the synthesized image on the display unit.

2. The method as claimed in claim 1, wherein the predetermining ones of the fixed number of bits used to represent the color information of the background in the first image area are upper bits and the predetermined remaining ones of the fixed number of bits used to represent the grey scale information of the character are lower bits of the fixed number of bits.

3. The method as claimed in claim 1, wherein the synthesizing device is a look-up table memory and data from the image memory are output to the look-up table memory as addresses.

4. The method as claimed in claim 1, wherein the character color information and background color information are mixed at ratios determined on the basis of the gray scale value of the pixels present in the first image area to thereby gradually deemphasize and blend the character into the background.

5. The method of claim 1, said synthesizing step including calculating the color information of each pixel of the character according to:

space="preserve" listing-type="equation">Ci=f(Ki,Kmax, P, B)

Ci=color information of each pixel of the character,

Ki=gray scale value for each pixel of the character,

Kmax=maximum gray scale value for each pixel of the character,

P=color information of a pixel at the center of the character,

B=color information of the background, and

f=a predetermined function.

6. The method of claim 5, said synthesizing step including calculating the color information of each pixel of the character according to:

##EQU6## P=color information of a pixel at the center of the character, C₁ =color information of each pixel of the character,

K_i =gray scale value for each pixel of the character,

K_max =maximum gray scale value for each pixel of the character, and

B=color information of the background.

7. The method of claim 5, wherein ##EQU7## g=another predetermined function.

8. A method for displaying an image including characters, so as to blend character color information into background color information, comprising the steps of:

assigning a grey scale value to each pixel of an image corresponding to the character color information, wherein the grey scale value is decreased as character color information approaches the character border, so as to blend the character color information into the background color information;

storing the background color information, using predetermined ones of a fixed number of bits and using remaining ones of the fixed number of bits to represent the grey scale value of each pixel of the image corresponding to the character color information, when a flag is set to a first value;

storing the background color information, using all of the fixed number of bits when the flag is set to a second value;

synthesizing the background and character color information based on the grey scale values stored so as to successively deemphasize characters from character center to character border, to blend the character color information into the background color information; and

displaying the synthesized information.

9. The method of claim 8, wherein the character color information and the background color information are mixed in ratios to thereby gradually deemphasize and blend the characters into the background.

10. The method of claim 9, wherein character center color information corresponds to a maximum grey scale value and the background color information corresponds to a minimum grey scale, with the remaining character color information corresponding to values therebetween.

11. The method of claim 8, said synthesizing step including calculating the color information of each pixel of the character according to:

space="preserve" listing-type="equation">Ci=f(Ki, Kmax, P, B)

Ci=color information of each pixel of the character,

Ki=gray scale value for each pixel of the character,

Kmax=maximum gray scale value for each pixel of the character,

P=color information of a pixel at the center of the character,

B=color information of the background, and

f=a predetermined function.

12. The method of claim 11, said synthesizing step including calculating the color information of each pixel of the character according to:

##EQU8## P=color information of a pixel at the center of the character, C₁ =color information of each pixel of the character,

K_i =gray scale value for each pixel of the character,

K_max =maximum gray scale value for each pixel of the character, and

B=color information of the background.

13. The method of claim 11, wherein ##EQU9## g=another predetermined function.