Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
277 words
A method for producing from character outline descriptions improved grayscale pixmap characters with strengthened thin character parts, with bars having at least one high-contrast edge, and with a bar intensity profile and a stem intensity profile preserved across the characters of a given character set, such a method comprising the steps of: a) modifying the heights of characters by placing their horizontal reference lines on pixel boundaries of the target pixmap, thereby producing high-contrast transitions between background colour and character colour at edges of horizontal bars adjacent to horizontal reference lines, and obtaining horizontal bars adjacent to horizontal reference lines with at least one high-contrast edge; b) verifying if character strokes are thinner than 3/4 of a pixel width and if this is the case computing a new stroke width by enlarging their width to the mean value between the measured stroke width and 1.5 pixel width, thereby obtaining characters with strengthened thin character parts; c) modifying the placement of vertical bars by placing their left boundary on a pixel boundary thereby obtaining bars having at their left boundary a high-contrast transition between background colour and character colour and therefore at least one high-contrast edge; d) modifying the placement of vertical and horizontal curved stems by placing the curved stem on the grid in such a way that the phase of the extremum of the external contour of the curved stem with respect to the grid is the same as the phase of the contour extremum at the optical correction point of character "O" for capital letters respectively of character "o" for lower-case letters, thereby ensuring that the same curved character parts have the same intensity profile.
Claim 2
Independent Claim
277 words
A method for producing from character outline descriptions improved grayscale pixmap characters with strengthened thin character parts, with bars having at least one high-contrast edge, and with a bar intensity profile and a stem intensity profile preserved across the characters of a given character set, such a method comprising the steps of: a) modifying the heights of characters by placing their horizontal reference lines on pixel boundaries of the target pixmap, thereby producing high-contrast transitions between background colour and character colour at edges of horizontal bars adjacent to horizontal reference lines, and obtaining horizontal bars adjacent to horizontal reference lines with at least one high-contrast edge; b) verifying if character strokes are thinner than 3/4 of a pixel width and if this is the case computing a new stroke width by enlarging their width to the mean value between the measured stroke width and 1.5 pixel width, thereby obtaining characters with strengthened thin character parts; c) modifying the placement of vertical bars by placing their left boundary on a pixel boundary thereby obtaining bars having at their left boundary a high-contrast transition between background colour and character colour and therefore at least one high-contrast edge; d) modifying the placement of vertical and horizontal curved stems by placing the curved stem on the grid in such a way that the phase of the extremum of the external contour of the curved stem with respect to the grid is the same as the phase of the contour extremum at the optical correction point of character "O" for capital letters respectively of character "o" for lower-case letters, thereby ensuring that the same curved character parts have the same intensity profile.
Claim 3
Dependent Claim
46 words
The method of claim 1, where step c) for improving the contrast of bars by ensuring at least one high-contrast edge is also applied to character terminals and stroke ends so as to produce sharp terminals and stroke ends having at least one high contrast edge.
Claim 4
Dependent Claim
136 words
The method of claim 1, where in the case of a stroke made of a vertical bar, the steps of enlarging the width of a stroke and of modifying the placement of a vertical bar are combined into one large step comprising the computation of a new bar width, the determination of a pixel boundary nearest to the left bar boundary, the computation of a first displacement value to be applied to the left boundary, the computation of the position of a new right bar boundary according to the new bar width, the computation of a second displacement value to be applied to the right bar boundary, the displacement of the left bar boundary according to the first computed displacement value and the displacement of the right bar boundary according to the second computed displacement value.
Claim 5
Dependent Claim
221 words
The method of claim 1, where in the case of a stroke made of a curved stem, the steps of enlarging the width of a stroke and of modifying the placement of a curved stem are combined into one large step comprising the computation of the new stem width, the computation of the phase of the contour of character "O" for capital letters, respectively of character "o" for lower-case letters at the optical correction point, the determination of the location of said phase closest to the external curved stem contour extremum, the computation of a first displacement value to be applied to the external curved stem contour extremum in order to move it to the previously determined phase location, the determination of a new internal curved stem contour extremum by subtracting in the case of a positive curved stem orientation, respectively by adding in the case of a negative curved stem orientation, to the previously determined phase location said new stem width, the computation of a second displacement value to be applied to the internal curved stem contour extremum in order to move it to the previously determined new internal curved stem contour extremum, the displacement of the external curved stem contour by said first displacement value and the displacement of the interior curved stem contour by said second displacement value.