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process, to cause the strokes to be close to an integer number of pixels and thickness and to compensate for thing and thickening which the printing engine might produce; bringing |
the leading and trailing edges of the characters to integer pixel locations, where such locations are based on and scaling the character between the leading and trailing edges proportionally therebetween, |
and producing a rasterized font from the altered contour font character. These and other aspects of the invention will become apparent from the following description used to illustrate a preferred |
embodiment of the invention in conjunction with the accompanying drawings in which: FIG. 1 shows a block diagram of the inventive optimized scaler rasterizer system. FIGS. 2A-2E illustrate the development |
of a raster font from a contour font, using the system described in FIG. 1. With reference to the drawing, where the showing is for the purpose of illustrating an |
embodiment of the invention and not for the purpose of limiting same, the Figure shows a block diagram of the present invention which will be referred to and described hereinafter. |
FIG. 1 shows a block diagram of the contour rasterization process of the present invention. Beginning with a contour font 10, and with a character "H" shown in contour for |
illustration purposes at FIG. 2A the contour font is analyzed initially at hint generation step 20. At the hint generation, the parameters defining the font are determined, including measurement of |
the following metrics and character hints: TABLE 1______________________________________Font Metric Comments______________________________________Cap-height Height of the H, I or similar letterX-Height Height of the lower case xAscender Height of the lower case k, |
b, or similar letterDescender Position of the bottom of the lower case p or qThickness of Upper Vertical stroke thicknessCase Stems on upper case H or KThickness of Upper Horizontal |
Stroke onCase Cross-Strokes upper case E or FThickness of Lower Vertical stroke thicknessCase Stems on lower case k or lThickness of Lower Case Horizontal strokeCross-Strokes thickness on the fThickness of |
AuxiliaryCharacter StemsThickness of AuxiliaryCharacter Cross-StrokesHairline thickness Thickness of the cross bar on the e or the thin part of the o______________________________________ (See, Appendix, page 13, ICFFontIODefs. Mesa) Character hints are |
generated for each character and include the following: TABLE 2______________________________________Character Metric Comments______________________________________Position of all horizontal Left sides of strokes areedges and indications of leading edges and rightwhether each edge is |
a sides or strokes areleading or trailing edge. trailing edges.Position of all verticaledges and indication ofwhether each edge is aleading or trailing edge.Direction of the normalvector (perpendicular)to the contour at |
eachcontrol point in thecontour, pointingtoward the whiteregion.______________________________________ At hint generation 20, the font metrics and character hints are computed. Since no special information on the actual character contours, beyond the |
contours themselves, is required to perform these computations, any font may be accepted as input. Height thickness metrics are obtained either by examining images of specific individual characters or by |
averaging amongst several characters. Optionally, if these values are supplied externally, that is, the provider of the font provides these values, the external values may be used instead of the |
computed values. Edge positions are determined by looking for long vertical or horizontal portions of contours. Normal vectors are perpendicular to the contour, and are computed from contour equations and |
by determining which side of the contour is black and which side is white. For those points required for curve reconstruction, but which are not on the curve, the normals |
are calculated as if a normal vector extended from the curve through those points. In the attached Appendix, the source code, in the MESA language of the Xerox Corporation, is |
provided demonstrating one possible embodiment of the source code to accomplish the described goals. The Mesa programming language operates on a microprocessor referred to as the Mesa microprocessor, which has |
been well documented, for example, in Xerox Development Environment, Mesa Language Manual, Copyright 1985 Xerox Corporation, Part No. 610E00170. This particular software is derived from the Typefounders product of the |
Xerox Corporation, Stamford, Conn. The Typefounders product accomplished all these character and font metrics, but did not provide them externally. (See Appendix, pages 67-319,for relevant Typefounder software modules called by |
software implementing the current invention including: CharacterOpsDefs.mesa, CharacterOpslmplA.mesa, CharacterOpslmpIB.mesa, pages 67-105; ContourOpsDefs.mesa, ContourOpslmplA.mesa, ContourOpslmplB.mesa, ContourOpslmpIC.mesa, ContourOpslmplD.mesa, pages 106-195; FontOpsDefs.mesa, FontOpslmpl.mesa, pages 196-221; Image... |
pages 266-319) Additional software was added, which makes these values available for subsequent processing (See Appendix, page 1, TypeDefs.mesa for translation of the Typfounder data structure; page 36, MetricsDef.mesa, Metricslmpl.mesa, |
for measurement of font metrics; page 47, EdgeOpsDef. mesa, EdgeOpslmpl.mesa, for measurement of leading and trailing edge position) and performs the perpendiculars calculations (see, Appendix, page 56, NormalOpsdefs.mesa, NormalOpslmpl.mesa). This |
information is used for creation of a data structure for "hints" (see, Appendix, page 13, ICFFontlODefs. Mesa for creation of hint format for next steps). Of course, while in the |
Appendix, the various coded algorithms operating on the contour font data for the hint creation step 20 are given in the Mesa language, implementation is easily made in the Unix-based |
"C" language. The remainder of the system, and the algorithms incorporated will be described in the Appendix in the Unix-based "C" language. Selecting a contour font for use enables a |
program that looks for font data, and designates its final position in an output, while calling the various programs forming the steps that will be described further hereinbelow (see, Appendix, |
page 320, raster.c). The contour font rasterization program herein described is useful on a variety of hardware platforms, attributes of which can be selected for enhanced operation of the system, |
such as for example, a greater degree of precision in the calculations (the difference between 8 bit calculation and 32 bit calculation). (see, Appendix, page 340, std.h) At transform step |
30, (see, Appendix, page 343, xform.c) the contour font is converted from arbitrary contour font units, which are supplied by the provider of the font, to a particular size, expressed |
in units of pixels. Typically, contour font units are provided in terms of the contour itself, i.e., the height or size of the contour font is one (1). That is, |
lengths of characters are placed in terms of the size of the font character itself. These values must be transformed into pixel unit values, or whatever other value is required, |
e.g. the scaled font may be 30 pixels tall. Additionally, it is at this point that the contour font is rotated for either landscape or portrait mode printing, as required. |
Rotation and scaling is accomplished in accordance with a previously determined transformation matrix equation 35, which mathematically determines the conversion of the contour font from font measurements to pixel values |
at a selected orientation which can be used by the printer. The transformed character H is shown at FIG. 2B. Subsequent to transformation step 30, at thickening or thinning step |
40, font characters are thickened or thinned based on requirements of the transformation, and requirements of the printing process. The character contour is adjusted to make the strokes thicker or |
thinner to compensate for the xerographic or other marking process to follow. There are three components of the thickening or thinning value. The first compensates for xerographic or other imaging |
effects. That is, if for example, the marking technology will thin strokes by half a pixel, then strokes are thickened by half a pixel in this step. The amount of |
thickening or thinning specified in the printer profile 50 separately for X and Y directions, and is created at the manufacturer of the printer, and inserted at the printer profile |
50. (see, Appendix, page 348, thicken.c) The second component of thickening, called residual thickening, is applied to insure uniformity of output strokes after the sampling or rasterization step. This amount |
for horizontal thickening on upper case letters, for example, is equal to the difference between the calculated ideal output vertical stem thickness, which is obtained by scaling the font metric |
to the proper size, and the result of rounding that thickness off to the actual pixel width which will be obtained after rasterization. This rounding is performed to the nearest |
whole pixel if half bitting is not enabled and to the nearest half pixel, if half bitting is enabled. There are separate values for horizontal or vertical directions and for |
upper case, lower case and auxiliary characters. The third component of thickening and thinning applies only to very small characters, and prevents drop-outs of fine lines. This amount is equal |
to the difference between the calculated scaled thickness of the hairlines, after thickening by the font thickening steps, and the minimum stroke thickness specified in the printer profile. When applied, |
this thickening brings fine lines up to the value of the minimum stroke thickness. The value is zero if the hairline is already greater than the minimum stroke thickness. (This |
process, referred to as "adaptive thickening," is not disclosed in the source code in the Appendix.) The actual thickening or thinning applied is equal to the sum of these three |
components. Each component has an independent value in the X and Y directions. The direction to move each contour control point is specified by its normal vector. The thickened character |
H is shown at FIG. C. At step 60, the snap function or grid alignment function is applied. The coordinate system of the character is varied in the horizontal direction |
to move vertical and horizontal edges to positions where pixel boundaries will be after rasterization, i.e., to a whole pixel position. This is to assure uniform stroke thickness in the |
rasterized character images. The process is to piecewise stretch or shrink the character to force edges to align the pixel boundaries. On the left hand sides of the characters, the |
left edge of each stroke is moved to the closest pixel boundary, while the right edge of the stroke is moved to the pixel boundary specified by rounding the stroke |
thickness. This process gives priority to maintaining uniform stroke thickness over absolute stroke position. That is to say, that after the left edge of the character has been moved to |
a whole pixel position, the thickness of the stroke, or portion of the character, is examined to determine its thickness. The thickness has already been adjusted in the thickness of |
thinning step, so that it is close to a whole pixel width. Accordingly, the right edge of the character is then moved to the nearest whole pixel, based on rounding |
the thickness of the pixel, as opposed to moving the right hand side to the nearest pixel. On the right hand sides of characters, the rolls of left and right |
edges of strokes are reversed. Right edges of strokes are anchored, while left edges are rounded relatively to corresponding right edges. (see, Appendix, page 355, snap.c). In one variant of |
this scheme, the positions of left and right index points or width points, which are those points which determine character spacing and are made to coincide in constructing words, are |
snapped before the vertical edges. In the vertical direction, snapping is performed to piecewise stretch characters so that positions of baseline, cap-height, x-height, and descender fall on pixel boundaries. Baseline |
and descender position are treated as bottoms of strokes, that is, anchored, while cap-height and x-height are treated as tops of strokes, computed relative to the baseline. All characters are |
snapped to all of these positions, ensuring uniform character alignment. After these font metric positions are snapped, horizontal edges are snapped in the same manner as vertical edges, with lower |
edges of strokes anchored and upper edges snapped relative to the lower edges in the lower half of the character and upper edges of strokes anchored and lower edges snapped |
relative to the upper edges in the upper half of the character. In both horizontal and vertical directions, snapping is performed one edge at a time. That is, the first |
edge is snapped, stretching the coordinate system of the character slightly on one side of the snapped edge and shrinking it slightly on the other side. The second edge is |
then snapped, with its pre-snapping position perhaps already modified slightly by the first snap. This sequential snapping helps preserve local character features better than simultaneous snapping of all edges does. |
When the second edge is snapped, its area of influence on the coordinate grid extends only up to the first snapped edge, which stays in place. This process is then |
repeated for the remainder of the edges. The snapped character H is shown at FIG. 2D. Once each character in the adjusted contour font has been placed in the grid |
and appropriately thickened and thinned, the final step is to sample the adjusted contour on discrete grid. This step 70 can optionally produce half bitted output images, as controlled by |
the printer profile. Light half bitting produces half bitting on curves and diagonals, while heavy half bitting will also produce half bitted vertical and horizontal edges. Rasterization in a preferred |
embodiment of this invention is in accordance with the process described in U.S. patent application Ser. No. 07/416,211 by S. Marshall, entitled "Rapid Halfbitting Stepper", and assigned to the present |
assignee of the present invention. This application is incorporated by reference herein for the purposes of teaching rasterization. (see, Appendix, page 364, step.c and page 368, step.h for rasterization with |
halfbitting; page 372, bezline.c for stepping around curve; page 396, fill.c for filling). The rasterized character is shown at FIG. 2D. It will not doubt be appreciated that numerous changes |
and modifications are likely to occur to those skilled in the art, and it is intended in the appended claims to cover all those changes and modifications which fall within |
Should I Be a Strict or Lenient Parent? To be strict or not to be strict, that is the question – in fact, it’s the number-one question among child-rearing and education authorities, among teachers and, of course, parents. It’s doubtful that there is a parent who hasn’t at one time or another agonized over this. There i... |
on how to be at home (or how to come across in the classroom) – tough or soft, to be a strict disciplinarian or a permissivist. Have you noticed, however, that you seldom hear a parent or teacher admit “I am authoritarian” or “I am permissive”? These are terms reserved for those with whom you disagree. The question, wh... |
be strict or lenient, never ceases to be debated in books and articles, or at conferences and conventions. Dr. Gordon points out that this question is what social scientists call a “pseudo problem” and how it also is a clear case of “either-or thinking”. Let’s take a look at what he means by that. Seldom parents or tea... |
recognize that it is not necessary to make a choice between these two leadership styles. Few adults know it, but there is an alternative to being at either end of the strictness-leniency scale. There is the choice of a third style. This alternative is being neither authoritarian nor permissive, neither strict nor lenie... |
middle of the scale–moderately strict or moderately lenient? Not at all. The alternative is not being on the scale at all! How so? Authoritarian leadership–whether at home or in the classroom–means that the control is in the hands of the adult leader. It has been researched and proven for decades how ineffective mainta... |
fearful and subservient children and/or rebellion. Still, no parent or teacher really wants to suffer the chaotic consequences of unrestricted freedom and lawless permissiveness either. It’s also true that most children are uncomfortable with the consequences of permissiveness. Permissive leadership means that control ... |
guilty about always getting their way. They also feel insecure about being loved, because their inconsiderate behaviors make them feel unlovable. So what is that third viable alternative to both, authoritarian and permissive adult leadership? It’s what Dr. Gordon in detail describes in his model of parenting, a set of ... |
geared toward rearing self-disciplined children in a harmonious family climate. For now, let’s just emphasize that this new approach to relating to youngsters requires a transformation in the way adults perceive children, as well as a shift in the way they treat them. This transformation can be accomplished by learning... |
everyday life. This newsletter will describe and examine each of these skills and methods in its future editions and hopefully contribute to you having a more harmonious and peaceful home. |
To the profound comprehension of this law of the intellectual generation of ideas, are due the marvels of Catholic civilisation. To that wonderful civilisation is due all that we admire and all that we see. Its theologians, even considered humanly, put to the blush modern and ancient philosophers; her doctors excite wo... |
comprehensive views, cast those of antiquity into the shade. St Augustine’s “City of God” is, even today, the most profound book of history which genius, illuminated by the rays of Catholicity, has presented to the astonished eyes of men. The acts of her Councils, leaving aside the divine inspiration, are the most fini... |
and the feudal, laws. Who is before St Thomas in science, St Augustine in genius, Bossuet in majesty, St Paul in power? Who is greater as a poet than Dante? Who is equal to Shakespeare? Who surpasses Calderon? Who, like Raphael, infused life and inspiration into the canvas? Place people in sight of the pyramids of Egyp... |
passed a grand and barbarous civilisation.” Place them in sight of the Grecian statues and temples, and they will tell you, “Here has passed a graceful, ephemeral, and brilliant civilisation.” Place them in sight of a Roman monument, and they will tell you, “Here has passed a great people.” Place them in sight of a cat... |
beauty, such grandeur to such taste, such grace to such delicacy, such severe unity to such rich variety, such measure to such boldness, such heaviness in the stones, with such suavity in their outlines, and such wonderful harmony between silence and light, shade and colour, they will tell you, Here has passed the grea... |
that people must have taken grandeur from the Egyptian, brilliancy from the Greek, strength from the Roman, and, beyond the strength, the brilliancy, and grandeur, something more valuable than grandeur, strength, and brilliancy—immortality and perfection. Donoso Cortes, Essays on Catholicism, Liberalism and Socialism |
SAN ANGELO, Texas — MOSCOW (AP) The head of Russia's space agency said Tuesday that cosmic radiation was the most likely cause of the failure of a Mars moon probe that crashed to Earth this month, and suggested that a low-quality imported component may have been vulnerable to the radiation. Vladimir Popovkin also said ... |
Space Station is being postponed from March 30 because of faults found in the Soyuz capsule. The statements underline an array of trouble that has afflicted the country's vaunted space program in recent months, including the August crash of a supply ship for the space station and last month's crash of a communications ... |
space shuttle program last year, Russian craft are the only means to send crew to and from the ISS. The unmanned Phobos-Ground probe was to have gone to the Mars moon of Phobos, taken soil samples and brought them back. But it became stuck in Earth orbit soon after its launch on Nov. 9. It fell out of orbit on |
Jan. 15, reportedly off the coast of Chile, but no fragments have been found. The failure was a severe embarrassment to Russia, and Popovkin initially suggested it could have been due to foreign sabotage. But on Tuesday he said in televised remarks that an investigation showed the probable cause was "localized influenc... |
the city of Voronezh where the report was presented to Deputy Prime Minister Dmitry Rogozin, said two units of the Phobos-Ground probe's onboard computer system went into an energy-saving "restart" mode, apparently due to the radiation, while the craft was in its second orbital circuit. It was not immediately clear why... |
mode. Popovkin said that some microchips used on the craft were imported and possibly of inadequate quality to resist radiation. He did not specify where the chips were manufactured. Yuri Koptev, a former space agency head who led the Phobos-Ground investigation, said 62 percent of the microchips used in the probe were... |
used in space flight. Popovkin said the craft's builder, Moscow-based NPO Lavochkin, should have taken into account the possibility of radiation interfering with the operation and said Lavochkin officials would face punishment for the oversight. Popovkin later announced that a March 30 planned launch of three astronaut... |
because of problems with the capsule. He did not specify, but the state news agency RIA Novosti cited the director of Russia's cosmonaut-training program as saying leaks had been found in the capsule's seals. It would be the second significant postponement of a manned Russian launch in the past year. The August crash o... |
European ports install radiation detectors as U.S. delays Just last week, U.S. officials announced that the Homeland Security Department is slowing plans to roll out 1,400 monitors, each costing nearly |
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