US5101443A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for reducing a pattern of binary pixels to one of lower resolution
Assignee: US Philips Corp
•
Filing: 1990-02-12
•
Granted: 1992-03-31
•
Expires: 2010-02-12
Abstract
Abstract Method and apparatus for converting a pattern, consisting of a matrix of binary pixels and representing a pseudo half-tone picture in particular, into a pattern having a lower resolution, in which the picture to be reduced is subdivided into fields and the pixels having a predetermined binary value in each field are counted, as a result of which a reduced quasi-real grey-tone picture develops. This grey-tone picture is compared to thresholds of a repeatedly used threshold matrix and the comparison results then provide the binary pixels of the reduced pseudo half-tone picture. A further reduction is obtained in that at a regular distances fields or grey-tone pixels respectively, are omitted from the fields of the matrix of the picture to be reduced or from the pixels of the grey-tone picture produced meanwhile.
Inventors
- 👤 Jens Behrmann-Poitiers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:19
CPC Classifications
G; G06; G06T; G06T5/00; G06T5/20; G06T3/00; G06T3/40; G06T3/4007; H; H04; H04N; H04N1/00; H04N1/40; H04N1/40075
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
145 words
Method of converting first digital signals representing a first pattern in the form of a first matrix of binary pixels into second digital signals representing a second pattern in the form of a second matrix of binary pixels having fewer binary pixels than the first matrix comprising subdividing the first matrix into two-dimensional fields, each field being associated with at most one binary pixel in the second matrix, determining a pixel number matrix of pixel numbers for respective fields of said first matrix associated with the binary pixels of the second matrix by counting binary pixels of one binary value within respective fields, subdividing said pixel number matrix into two-dimensional pixel number sub-matricies, and comparing the pixel numbers at positions within said sub-matrices to respective associated threshold values at corresponding positions in a matrix of different threshold values of the same dimensions as said sub-matrices.
Claim 2
Dependent Claim
145 words
Method of converting first digital signals representing a first pattern in the form of a first matrix of binary pixels into second digital signals representing a second pattern in the form of a second matrix of binary pixels having fewer binary pixels than the first matrix comprising subdividing the first matrix into two-dimensional fields, each field being associated with at most one binary pixel in the second matrix, determining a pixel number matrix of pixel numbers for respective fields of said first matrix associated with the binary pixels of the second matrix by counting binary pixels of one binary value within respective fields, subdividing said pixel number matrix into two-dimensional pixel number sub-matricies, and comparing the pixel numbers at positions within said sub-matrices to respective associated threshold values at corresponding positions in a matrix of different threshold values of the same dimensions as said sub-matrices.
Claim 3
Dependent Claim
64 words
Method as claimed in claim 1, wherein said pixel number matrix determined is a first pixel number matrix, and further comprising forming a second pixel number matrix dimensionally smaller than said first pixel number matrix by selecting first pixel numbers associated with non-adjacent fields of said first pixel number matrix, said comparing being of respective second pixel numbers to said respective associated threshold values.
Claim 4
Dependent Claim
217 words
Apparatus for converting first digital signals representing a first pattern in the form of a first matrix of binary pixels into second digital signals representing a second pattern in the form of a second matrix having fewer binary pixels than the first matrix, said first matrix being subdivided into two-dimensional fields such that each field is associated with at most one binary pixel in said second matrix, said apparatus comprising a counter for counting binary pixels of one binary value within respective fields of the first matrix associated with binary pixels of the second matrix and forming thus a pixel number matrix containing pixel numbers for respective fields, said pixel number matrix being divided into two-dimensional sub-matrices of equal dimensions, a comparator for comparing a pixel number for a field to a threshold value for that field, a threshold value memory for storing a threshold value matrix of the same dimensions as said sub-matrices and containing a plurality of different threshold values associated with the positions of fields within said sub-matrices, and an addressing means for reading for a respective field, based on the position of the field within a sub-matrix, a threshold value from the threshold value memory at a corresponding position in the threshold value matrix and applying the threshold value read to the comparator.
Claim 5
Dependent Claim
217 words
Apparatus for converting first digital signals representing a first pattern in the form of a first matrix of binary pixels into second digital signals representing a second pattern in the form of a second matrix having fewer binary pixels than the first matrix, said first matrix being subdivided into two-dimensional fields such that each field is associated with at most one binary pixel in said second matrix, said apparatus comprising a counter for counting binary pixels of one binary value within respective fields of the first matrix associated with binary pixels of the second matrix and forming thus a pixel number matrix containing pixel numbers for respective fields, said pixel number matrix being divided into two-dimensional sub-matrices of equal dimensions, a comparator for comparing a pixel number for a field to a threshold value for that field, a threshold value memory for storing a threshold value matrix of the same dimensions as said sub-matrices and containing a plurality of different threshold values associated with the positions of fields within said sub-matrices, and an addressing means for reading for a respective field, based on the position of the field within a sub-matrix, a threshold value from the threshold value memory at a corresponding position in the threshold value matrix and applying the threshold value read to the comparator.
Claim 6
Dependent Claim
45 words
Apparatus as claimed in claim 3, further comprising an intermediate memory for storing said pixel numbers and wherein the addressing means is also for reading for a field, the associated pixel number from the intermediate memory and applying the pixel number read to the comparator.
Claim 7
Dependent Claim
26 words
Apparatus as claimed in claim 3, wherein said addressing means is configured to read threshold values for only fields which are not adjacent to each other.
Claim 8
Dependent Claim
34 words
Apparatus as claimed in claim 3, wherein the addressing means is also for controlling application of binary pixels to the counter and wherein the output of the counter is coupled directly to the comparator.
Claim 9
Dependent Claim
26 words
Apparatus as claimed in claim 4, wherein said addressing means is configured to read threshold values for only fields which are not adjacent to each other.
Claim 10
Dependent Claim
34 words
Apparatus as claimed in claim 6, wherein the addressing means is also for controlling application of binary pixels to the counter and wherein the output of the counter is coupled directly to the comparator.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-03-31 | 1995-09-30 | 1996-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-31 | 1999-09-30 | 2000-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-31 | 2003-09-30 | 2004-03-31 | $7700.00 | Window Closed / Lapsed |