Facsimile and static presentation processing – Static presentation processing – Attribute control
Reexamination Certificate
1998-08-19
2001-07-24
Rogers, Scott (Department: 2624)
Facsimile and static presentation processing
Static presentation processing
Attribute control
C358S462000, C382S205000, C382S271000, C382S173000
Reexamination Certificate
active
06266156
ABSTRACT:
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to an area judging apparatus for judging multiple areas of character portions, photograph portions, halftone dot portions and the like of the image in digital copying machines, digital printers, digital facsimile machines or the like.
(2) Description of the Prior Art
It is necessary to perform the optimum processing according to the properties of the original document image in order to realize the high quality of the recorded image. For that purpose, in the case of an original document in which character portions, photograph portions and halftone dot portions coexist together, area judgement is performed. In such case, the accuracy of the judgement becomes an important problem.
As a method for judging the halftone (dot) photograph and the character area, there is proposed a method in which after performing a processing for emphasizing the coefficient of a high frequency domain by the filtering processing, and binarizing into binary value, judgement is performed depending upon the presence or absence of closed areas of white or black in a predetermined area (see Japanese Patent Publication Hei 5 No. 28944).
In the above Japanese Patent Publication Hei 5 No. 28944, however, only a judgement if it is a halftone (dot) photograph area or a character area is performed for a predetermined area unit (for example, minimum 3 pixels×3 pixels). Therefore, fine judgement of multiple areas such as a character area, a photograph area, or a halftone dot area cannot be performed.
SUMMARY OF THE INVENTION
It is therefore the object of the present invention to provide an area judging apparatus which does not require the pre-processing such as filtering or the like, and which can perform the judgement in one pixel unit, and set three areas of character area, photograph area and halftone (dot) area, or an intermediate area among them, thereby finer judgement becomes possible.
Another object of the present invention is to provide an area judging apparatus in which when a plurality of characteristic parameters is adopted, the judgement accuracy is further improved, and by controlling the judgement rule according to conditions, a judgement result can be obtained with higher accuracy.
With a view of attaining the above objects, the gist of the present invention is as follows.
The first gist of the present invention is an area judging apparatus for judging multiple areas including character portions, photograph portions and dot portions, comprising:
binarizing means which designates a block of a predetermined number of pixels centering around target pixels among the image data as a mask, and compares the pixels in the mask with a threshold to binarize it into binary value;
linkage degree-calculating means for calculating the linkage degree indicating the linking condition of black pixels, based on the number of black pixels for each line in each direction in the binarizing mask; and
area judging means for designating the linkage degree as a characteristic value, and judging an area of the target pixels based on the characteristic value.
The second gist of the present invention is an area judging apparatus for judging multiple areas including character portions, photograph portions and dot portions, comprising:
binarizing means which designates a block of a predetermined number of pixels centering around target pixels among the image data as a mask, and compares the pixels in the mask with a threshold to binarize it into binary values;
linkage degree-calculating means for calculating the linkage degree indicating the linking condition of black pixels, based on the number of black pixels for each line in each direction in the binarizing mask;
density parameter-calculating means for calculating the density parameter from the density of the black pixels in the binarizing mask; and
area judging means for designating the linkage degree and the density parameter as the characteristic value, and judging an area of the target pixels based on the characteristic value.
The third gist of the present invention is an area judging apparatus according to the gist
2
, wherein the density parameter-calculating means designates (maximum value—minimum value) of the density of pixels in the mask as the density parameter.
The 4th gist of the present invention is an area judging apparatus according to the gist
2
, wherein the density parameter-calculating means calculates the sum total of the difference in the density of successive 2 pixels, with respect to the main scanning direction and in the sub scanning direction in the mask, respectively, and designates the smaller one as the density parameter.
The 5th gist of the present invention is an area judging apparatus according to the gist
2
, wherein the density parameter-calculating means calculates (maximum value—minimum value) of the density of pixels in the mask, and the sum total of the difference in the density of successive 2 pixels, with respect to the main scanning direction and the sub scanning direction in the mask, respectively, and designates the smaller one as the density parameter.
The 6th gist of the present invention is an area judging apparatus according to the gist
1
, wherein the threshold is the mean value of the density of pixels in the mask.
The 7th gist of the present invention is an area judging apparatus according to the gist
2
, wherein the threshold is the mean value of the density of pixels in the mask.
The 8th gist of the present invention is an area judging apparatus according to the gist
1
, wherein the threshold is a value which is varied so that there is a difference between the linkage degree for each area, with respect to the mean value of the density of pixels in the mask.
The 9th gist of the present invention is an area judging apparatus according to the gist
2
, wherein the threshold is a value which is varied so that there is a difference between the linkage degree for each area, with respect to the mean value of the density of pixels in the mask.
The 10th gist of the present invention is an area judging apparatus according to the gist
1
, wherein the linkage degree-calculating means counts the number of black pixels in each line both in the main scanning direction and in the sub scanning direction from the results of binarization in the mask, and designates the largest value among them as the linkage degree.
The 11th gist of the present invention is an area judging apparatus according to the gist
2
, wherein the linkage degree-calculating means counts the number of black pixels in each line both in the main scanning direction and in the sub scanning direction from the results of binarization in the mask, and designates the largest value among them as the linkage degree.
The 12th gist of the present invention is an area judging apparatus according to the gist
1
, wherein the linkage degree-calculating means counts the number of successive black pixels in each line both in the main scanning direction and in the sub scanning direction from the results of binarization in the mask, and designates the largest value among them as the linkage degree.
The 13th gist of the present invention is an area judging apparatus according to the gist
2
, wherein the linkage degree-calculating means counts the number of successive black pixels in each line both in the main scanning direction and in the sub scanning direction from the results of binarization in the mask, and designates the largest value among them as the linkage degree.
The 14th gist of the present invention is an area judging apparatus according to the gist
1
, wherein the linkage degree-calculating means counts the number of successive black pixels in each line both in the main scanning direction and in the sub scanning direction from the results of binarization in the mask, adds the results for successive plural lines, and designates the largest value among them as the linkage degree.
The 15th gist of the present invention is an area judging apparatus according to the gist
2
, wherein
Nakamura Masatsugu
Ohtsuki Masaaki
Tanimura Mihoko
Tokuyama Mitsuru
Conlin David G.
Dike Bronstein Roberts & Cushman IP Group
Rogers Scott
Sharp Kabushiki Kaisha
Tucker David A.
LandOfFree
Area judging apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Area judging apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Area judging apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2504659