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WO1992006553A1 - Technique de tramage de ligne pour un procede anti-crenelage n'utilisant par l'echelle des gris et destine a des imprimantes laser - Google Patents

Technique de tramage de ligne pour un procede anti-crenelage n'utilisant par l'echelle des gris et destine a des imprimantes laser Download PDF

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Publication number
WO1992006553A1
WO1992006553A1 PCT/US1991/007341 US9107341W WO9206553A1 WO 1992006553 A1 WO1992006553 A1 WO 1992006553A1 US 9107341 W US9107341 W US 9107341W WO 9206553 A1 WO9206553 A1 WO 9206553A1
Authority
WO
WIPO (PCT)
Prior art keywords
pixel
line image
line
ideal
raster
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US1991/007341
Other languages
English (en)
Inventor
John Mark Gilbert
Lawrence J. Lukis
Leonard R. Steidel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Laser Master Corp
Original Assignee
Laser Master Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US07/591,537 external-priority patent/US5212559A/en
Priority claimed from US07/612,686 external-priority patent/US5122884A/en
Application filed by Laser Master Corp filed Critical Laser Master Corp
Priority to JP4500659A priority Critical patent/JPH06504652A/ja
Publication of WO1992006553A1 publication Critical patent/WO1992006553A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T11/00—2D [Two Dimensional] image generation
    • G06T11/20—Drawing from basic elements, e.g. lines or circles
    • G06T11/203—Drawing of straight lines or curves
    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K15/00—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers
    • G06K15/02—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers
    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K2215/00—Arrangements for producing a permanent visual presentation of the output data
    • G06K2215/0002—Handling the output data
    • G06K2215/004—Generic data transformation
    • G06K2215/0042—Rasterisation
    • G06K2215/0045—Converting outline to bitmap
    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K2215/00—Arrangements for producing a permanent visual presentation of the output data
    • G06K2215/0002—Handling the output data
    • G06K2215/004—Generic data transformation
    • G06K2215/006—Anti-aliasing raster data
    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K2215/00—Arrangements for producing a permanent visual presentation of the output data
    • G06K2215/0002—Handling the output data
    • G06K2215/0062—Handling the output data combining generic and host data, e.g. filling a raster
    • G06K2215/0071—Post-treatment of the composed image, e.g. compression, rotation
    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K2215/00—Arrangements for producing a permanent visual presentation of the output data
    • G06K2215/0082—Architecture adapted for a particular function
    • G06K2215/0094—Colour printing

Definitions

  • This invention pertains to methods of rasterization and fill techniques used to create images for binary imaging devices, such as laser printers. More particularly, this invention pertains to a line rasterization technique for a non-gray scale anti-aliasing method for smoothing the edges of a line image to be produced by a laser printer.
  • desktop publishing offers users the ability to format and print documents having complicated layouts using characters that have a variety of different fonts and type sizes. While desktop publishing systems represent a significant advance in the art of publishing, the standard resolution of the laser printers used with such systems (typically a 300 X 300 dots per inch (dpi) Canon CX or SX-based laser printer, e.g. a Hewlett Packard LaserJet Series ⁇ printer) was too poor to compete with traditional phototypesetting systems.
  • dpi dots per inch
  • SX-based laser printer e.g. a Hewlett Packard LaserJet Series ⁇ printer
  • printer controller cards In an effort to improve the quality and speed of the smaller, inexpensive laser printers used with desktop publishing systems, a variety of printer controller cards have been introduced that may be installed either in the laser printer or in the personal computer. Certain of the printer controller cards that are installed directly in the personal computer increase the quality and speed of the laser printers by using a separate co-processor and page frame buffer to create a pixel representation of the image to be printed on the laser printer. This image is then printed from the pixel representation in the page frame buffer by directly controlling the modulation of the laser in the print-engine of the laser printer.
  • An example of such a printer control card is the LX6 Professional printer controller cards available from LaserMaster Corporation, Eden Prairie, Minnesota, the assignee of the present invention. In some of the prior art printer controller cards, such as the LX6
  • the LX6 Professional printer controller cards can increase the horizontal component of the pixel resolution of the laser printer to 600 X 300 dpi or 1000 X 400 dpi, depending upon the type of laser printer.
  • This increase in horizontal resolution significantly improves the quality of the resulting printed image, particularly for pixel transition points along the outline edges of a character or image that occur in the vertical or near vertical orientation.
  • the increased horizontal resolution does little to improve the quality of the outline edges of a character or image that are near horizontal in slope.
  • aliasing The noticeability and appearance of such vertical pixel transition points is typically referred to as aliasing that results in jagged or stairstep edges of the character or image outline oriented generally in the horizontal direction.
  • anti-aliasing techniques incorporating a gray-scale approach have been used in video displays to resolve this type of problem.
  • laser printers are binary imaging devices and are not capable of implementing such gray ⁇ scale techniques.
  • the problems associated with aliasing and non-smooth edges may be resolved by using higher pixel resolutions in these printers.
  • the method was specifically described for use by a processor that is provided with an ideal outline of the image and then rasterizes the ideal outline of the image using the processor for dete ⁇ nining which pixels to turn on and which pixels to turn off in a frame buffer that stores a pixel representation of the image to be printed by the laser printer.
  • the smoothing is accomplished by selectively modifying the on and off states of pixels on either side of each vertical transition point along the horizontal components of raster lines representing the edges of the pixel representation of the image.
  • the pixel representation created in the frame buffer for each horizontal raster line is used to control the laser in the laser printer.
  • the laser is turned on in response to an "on" pixel, a generally circular laser beam image is reflected on the print drum of the print engine to transfer charge elements to the drum.
  • the charge elements attract and pick up toner that is then transferred to a sheet of paper.
  • the pixel elements are thought of as square or rectangular shapes, in actuality, the edges of the pixels typically bleed into one another.
  • the parent application for the present invention taught that the vertical transition points in the horizontal raster lines could be smoothed by selectively adding and subtracting pixels around the transition points.
  • the smoothing of the horizontal components of the edges of the ideal outline is accomplished during the rasterization fill process for each horizontal raster line.
  • the processor accumulates a running fill value that represents the area of each pixel inside the ideal outline that should be turned "on” or filled. If the processor dete ⁇ nines that the area of the fill value is greater than the area of a pixel, the pixel presently being processed is turned “on” and the area of a pixel is subtracted from the fill value.
  • the fill value acts like a running accumulator with the carry out of the accumulator being used to determine whether the pixel presently being processed should be turned "on”.
  • non-gray scale anti-aliasing techniques of the parent applications have taught a method for smoothing the edges of jagged images, these techniques are not generally applicable to line images because of the lack of an ideal outline image. Accordingly, it would be desirable to provide for a line rasterization technique that would allow the non-gray scale anti-aliasing technique of the parent applications to be extended to smooth lines images to be printed on a laser printer, especially where the line width is approximately equal to or less than the pixel dimensions of the laser printer.
  • the present invention is a line rasterization technique for a non-gray scale anti-aliasing method for smoothing the edges of a single pixel width line image to be printed by a binary imaging printer.
  • the line image is generated by rasterizing an ideal line image using a processor means f r processing a plurality of raster lines to form a pixel representation of the line image to be communicated to the binary imaging printer.
  • the present invention smooths the line image by selectively modifying the on and off states of one or more pixels in an adjacent raster line on either side of the vertical transition point
  • the pixel representation of the line image is then communicated to the printer such that the printer may print the smoothed line image.
  • the stair-step or jagged effect that occurs in the present line rasterization technique is effectively smoothed using a non-gray scale anti-aliasing technique similar to that of the parent applications of the present invention. This allows the smoothing to be accomplished for the edges of single pixel width line images, in addition to the edges of ideal outline image.
  • a primary objective of the present invention is to provide new techniques for adapting the non-gray scale anti-aliasing method of the parent applications to the rasterization of single pixel width line images.
  • An additional objective of the present invention is to provide a new line rasterization technique that eliminates the stair-step transitions between adjacent raster lines.
  • Fig. 4 is a flow chart of the line rasterization technique in accordance with the preferred embodiment of the present invention.
  • Figs. 6a and 6b are schematic pixel representations (4X and 20X scales, respectively) of the same shallow horizontal single pixel width line as shown in Figs.5a and 5b with pixels selectively modified about each transition point using a replacement accumulator technique.
  • Figs.7a and 7b are similar to the schematic pixel representations of Figs. 6a and 6b, only using an additive accumulator technique for selectively modifying the pixels representing the line image.
  • Figs. 8a and 8b are similar to the schematic pixel representations of Figs. 6a and 6b, only using a lookup table comparison technique for selectively modifying the pixels representing the line image.
  • Figs.9a and 9b are similar to the schematic pixel representations of Figs. 6a and 6b, only using an alternative lookup table comparison technique.
  • Figs. 10a and 10b are similar to the schematic pixel representations of Figs. 6a and 6b, except that a restriction prohibiting single pixel replacements is used in selectively modifying the pixels representing the line image.
  • Figs. 2a-2c the differences between the prior art method of rasterizing a single pixel width line and the line rasterization technique of the present invention will be described.
  • the designation of the orientation of horizonal and vertical is arbitrary and refers, by convention, to the orientation of a raster line with respect to the top of a sheet of paper on which the images will be printed by the binary imaging printer. It should be noted that the present invention is equally applicable to both horizontal and vertical lines.
  • the terms horizontal and vertical will refer to the directions in which the line image will be rasterized (horizontal) and the direction in which the error from an ideal line image will be measured (vertical).
  • a portion of two adjacent horizontal raster lines 101 and 102 are shown.
  • Each raster line 101 and 102 is comprised of a plurality of pixels 104 and 105, respectively.
  • the pixels 104 and 105 are shown as square pixel of equal vertical and horizontal dimensions.
  • the pixels 104 and 105 are rectangular and have unequal vertical and horizontal dimensions in accordance with the preferred embodiment of the non-gray scale anti ⁇ aliasing method described hereinafter.
  • An ideal line image 110 (shown for reference as a dashed line) has an initial coordinate 112 and extents (dimensions) in both the horizontal (x) dimension and the vertical (y) dimension.
  • the ideal line image 110 has an x extent of 6 and a y extent of 1, resulting in a slope of 1/6 for the line.
  • ideal line image 110 in the preferred embodiment, either a slope of the line or an end coordinate for the line may also be used to define the ideal line image 110.
  • the ideal line image 110 may also be defined as a vector.
  • nothing in the present invention is meant to limit the line to a straight line. The present invention can work equally as well with shallow curves, or larger curves made up of multiple line segments.
  • the decision on whether to turn on or turn off a particular pixel to represent a single width pixel line is based solely on whether the ideal line image intersects the pixel. If the ideal line image intersects the pixel, then the pixel is on; if not, then the pixel is off.
  • a typical method in the prior art for accomplishing the rasterization of a single pixel width line is shown in the flow chart represented by Fig. 3.
  • the y pixel coordinate for the pixel currently being processed is either truncated or rounded to the nearest integer, resulting in the step-like change between the adjacent raster lines 101 and 102 that occurs at the transition point 120 where the ideal line image 110 intersects the common boundary 106 between the adjacent raster lines 101 and 102.
  • the present invention selectively modifies certain of the pixels 104 and 105 around the transition point 120 to produce a smoothing of the edges of the line image.
  • the pixels 104 and 105 modified as compared to the prior art method single pixel width line rasterization are shown in cross hatch.
  • the pixels 104 and 105 have unequal horizontal and vertical dimensions generated by the increased modulation of the laser in the laser printer as described in greater detail hereinafter.
  • an error height E is generated by comparing the height of the ideal line image 110 with the height of the center line 107 of the raster lines 101 currently being processed.
  • the error height E is determined with respect to the height of the ideal line image 110 at the center of the pixel 104 currently being processed.
  • this embodiment uses the center line 107 to dete ⁇ nine the error height E. It will be recognized, however, that many different ways of dete ⁇ nining the error height E could be utilized to achieve the smoothing results of the present invention.
  • an error height E- is determined based upon a comparison of the intersection of the ideal line image 110 with the center line 107 at either the left or right edge of the pixel 104.
  • an error height E 2 is determined based upon a comparison of the ideal line image 110 with the top or boundary line 106 or bottom 108 of the raster line 101.
  • Still another alternate method of determining an error height E 3 as shown in
  • Fig. 2c is to base the error height upon a comparison of the ideal line image 110 with an origin line 114 representing a horizontal line parallel to the initial vertical coordinate or the initial coordinates 112.
  • the error height E is added to an accumulated error value and the pixel 104 is turned on. If the accumulated error value exceeds a preselected threshold value, then the pixel
  • the accumulated error value acts as a smoothing window around the vertical transition 120 in which the pixels 104 and 105 of the adjacent raster lines 101 and 102 will be selectively modified (either on or off) as compared to the prior art rasterization techniques for single pixel width lines.
  • the preselected threshold is set at the vertical height of the pixels 104 and 105, although it will be recognized that many other values for the preselected threshold could be used and still be within the scope of the present invention.
  • the accumulated error value representing the accumulation of the error height E for pixels 104a, 104b, 104c and 104cd exceeds the value of the vertical height of the pixel 104. Therefore, the pixel 104d in raster line 101 is not turned on and the pixel 105d in raster line 102 is turned on.
  • the accumulated error value is reset by subtracting the vertical height of the pixel (in this case, still leaving a residual fractional value in the accumulated error value because the previous accumulated error value was greater than the vertical height of the pixel). This process is repeated with pixels 105f turned on instead of 104f.
  • the center line 113 of raster line 101 is used as the base for dete ⁇ nining the error height E until the ideal line image 110 crosses the center line 114 for raster line 102. Consequently, pixels 104g and 104i are turned on in raster line 101 and pixel 105h, 105j and 105k are turned on in raster line 102. At pixel 1051, the ideal line image crosses the center line 114 and now the error height E will be calculated from this center line. In this manner, the rasterization of the ideal line image 110 efficiently moves from adjacent horizontal raster line to raster line without the need to examine the entirety' of each raster line.
  • An example of the programming steps used to implement the preferred method of the present invention is presented in connection with the description of Figs. 4a and 4b set forth hereinafter.
  • the hardware for the desktop publishing system 10 is comprised of a personal computer 12 connected with a small, inexpensive laser printer 14.
  • the personal computer 12 may be any one of a variety of personal computers such as an IBM PC, XT/AT, 386, or PS/2, available from International Business Machines, Armonk, New York, or an Apple Macintosh, available from Apple Computers, Inc., Cuppertino, California.
  • the personal computer 12 may be provided with a desktop publishing software package, such as Ventura Publisher, available from Xerox Corporation, PageMaker, available from Aldus Corporation, or GEM Desktop Publisher, available from Digital Research, Inc.
  • the laser printer 14 may be any type of Canon CX or SX laser printer such as the HP LaserJet Series II available from Hewlett Packard, the LaserWriter, available from Apple Computer, Inc., or the
  • the personal computer 12 In normal operation without a printer controller card, the personal computer 12 includes a main PC mother board 16 and a serial port 18 through which the personal computer 12 communicates with the internal controller 20 of the laser printer 14. The computer 12 sends a serial bit stream to the laser printer 14 over an
  • RS-232-C serial interface 22 in the form of various commands and data that represent the image to be printed by the laser printer 14.
  • the internal controller 20 decodes the serial bit stream and generates the control signals that will be supplied to the laser 24 to drive the print engine 26 that creates the printed images corresponding to the various commands and data received by the internal controller.
  • the LaserJet II Printer User's Manual, Edition 1 available from
  • the page throughput for the laser printer 14 is typically very low, 6 pages per minute or less, depending upon the formatting and type of information being printed.
  • various printer controller cards 30 have been introduced into desktop publishing systems, such as the LX6 Professional, available from LaserMaster Corporation, Eden Prairie, Minnesota.
  • the printer controller card 30 of the preferred embodiment is located in the personal computer
  • the printer controller card 30 may be located in the laser printer 14 or that the present invention may be implemented within the internal controller 20 of the laser printer 14.
  • the printer controller card 30 is an LX6
  • the LX6 Professional controller consists of a frame buffer 32, a co-processor 34 and a video interface 36.
  • the co-processor 34 receives the various commands and data representing the image to be printed from the PC mother board 16 via the bus 28. Because the bus
  • the co-processor 34 decodes the commands and information and produces a mathematically pure ideal outline or line image corresponding to a filled polygon or single pixel width line image that will represent each image or character to be printed.
  • the co-processor 34 may also aid the personal computer 12 in rendering lines, graphics and characters as determined by the particular application software package currently being run on the personal computer 12.
  • the smoothing method of the present invention is applied by the co ⁇ processor 34 as it is generating each horizontal raster line 101, 102 to be stored in the frame buffer 32.
  • the horizontal raster lines 101, 102 are processed from top to bottom in the frame buffer 32 and the pixels 104, 105 are processed from left to right, although it will be recognized that the raster lines 101, 102 and pixels 104, 105 may be processed in any direction so long as the processing is consistent throughout an entire page in the frame buffer 32.
  • the ideal outline or line image is generated, it is then filled in or "rasterized” to produce a pixel representation of the image to be printed that is stored in the memory of the frame buffer 34. Any number of known fill techniques or algorithms may be used to fill in the pixels inside the outline, depending upon how overlapping images are to be handled.
  • the single pixel width line images are rasterized in accordance with the present invention.
  • the pixel representation in the frame buffer 34 is transferred to the laser printer 14 via the video interface 36 in the printer controller 30 that communicates directly with the laser 24 via a video cable 38.
  • An internal switch 40 in the laser printer 14 allows the printer controller 30 to override the internal controller 20 of the laser printer and directly modulate the laser 24.
  • FIG. 4 the operation of the preferred embodiment of the present invention are shown in terms of a traditional programming flow chart.
  • Figs. 5a and 5b are enlarged pixel representation showing the prior art method of line rasterization as applied to a single pixel width line.
  • Figs. 6a and 6b are enlarged pixel representation showing the results of the basic line rasterization technique of the present invention as applied to a single pixel width line.
  • Figs. 7a and 7b show the same single pixel width line as the basic line rasterization technique with the qualification that the selective modification operates only to turn on pixels in the adjacent raster line and none of the pixels in the raster line currently being processed are not turned on.
  • One of the variations is to include a check for the angle or slope of the line to see if rasterizing the line using the present invention is the most efficient rasterization.
  • the angle of the line is at or near 45°
  • the optimum rasterization of such a single pixel width line will be a sequence single pixel "stair steps" in the direction of the ideal line image.
  • the smoothing effect of the present invention will not be realized to the same extent as it will on shallower lines.
  • another embodiment of the present invention provides for a check of the slope of the ideal line image.
  • the ideal line image is processed in the horizontal direction in accordance with the present invention. If the slope is within the predefined range about 1, then the ideal line image is rasterized in the conventional manner. If the slope is greater than one by the predefined range, then the horizontal and vertical directions of processing the line are reversed and the line is processed horizontally as a "vertical" line.
  • Another variation is to use the duty cycle technique as described in the second parent application entitled DUTY CYCLE TECHNIQUE FOR A NON- GRAY SCALE ANTI-ALIASING METHOD FOR LASER PRINTERS, PCT Application No. PCT/US91/xxxxx, as an adjustment to the accumulation of the error height E.
  • the error height E is compared to at least a first and second comparison value to establish a range within which a predetermined duty cycle will be applied to rasterize all of the pixels within this range.
  • the error height E is used to access a lookup table containing adjustment values that are then used by an accumulator to produce the accumulated error value.
  • Figs. 8a and 8b and Figs. 9a and 9b are enlarged pixel representations showing the results of the duty cycle/lookup table line rasterization technique of the present invention as applied to a single pixel width line.
  • Still another variation of the present invention is used to prevent the "disappearance" of single pixels, especially pixels having unequal horizontal and vertical resolutions due to the increased modulation of the laser in the print engine.
  • the method of the present invention is modified to require that two adjacent pixels be turned on each time it is determined that a pixel in the window about the transition point should be selectively modified as compared to the conventional rasterization technique.
  • One method for accomplishing this double pixel limitation is to require that the accumulated error value exceed a preselected value that is equal to twice the vertical pixel height and then tuming on two pixels in a row before fully resetting the accumulated error value.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Facsimile Image Signal Circuits (AREA)
  • Image Generation (AREA)

Abstract

Une technique de tramage de ligne pour un procédé anti-crénelage n'utilisant pas l'échelle des gris lisse les bords d'une image de ligne d'une largeur d'un seul pixel devant être imprimée par une imprimante binaire. L'image de ligne est générée par le tramage d'une image de ligne idéale (110) sous la forme d'une pluralité de lignes de trame (101, 102) constituant une représentation en pixels de l'image de ligne devant être transmise à l'imprimante binaire (14). Pour chaque point de transition vertical (120) créé par l'image de ligne idéale (110) coupant deux lignes de trame adjacentes (101, 102), la technique présentée permet de lisser l'image de ligne en enlevant ou en ajoutant sélectivement un ou plusieurs pixels (104) dans une ligne de trame adjacente de chaque côté du point de transition vertical (120). La représentation en pixels de l'image de ligne est ensuite transmise à l'imprimante de sorte que l'imprimante puisse imprimer l'image lisse.
PCT/US1991/007341 1990-10-02 1991-10-02 Technique de tramage de ligne pour un procede anti-crenelage n'utilisant par l'echelle des gris et destine a des imprimantes laser Ceased WO1992006553A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP4500659A JPH06504652A (ja) 1990-10-02 1991-10-02 レザープリンターの非グレイスケール式折返し防止法におけるラインラスター化技法

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US591,537 1990-10-02
US07/591,537 US5212559A (en) 1989-11-13 1990-10-02 Duty cycle technique for a non-gray scale anti-aliasing method for laser printers
US07/612,686 US5122884A (en) 1989-11-13 1990-11-14 Line rasterization technique for a non-gray scale anti-aliasing method for laser printers
US612,686 1990-11-14

Publications (1)

Publication Number Publication Date
WO1992006553A1 true WO1992006553A1 (fr) 1992-04-16

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JP (1) JPH06504652A (fr)
AU (1) AU8939391A (fr)
WO (1) WO1992006553A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0569657A1 (fr) * 1992-05-15 1993-11-18 BULL HN INFORMATION SYSTEMS ITALIA S.p.A. Dispositif pour détection et correction d'imperfections dans des images digitalisées
EP0741041A3 (fr) * 1995-05-04 1998-01-21 SCITEX DIGITAL PRINTING, Inc. Technique de dispersion sélective de gouttelette
US8722860B2 (en) 2009-04-16 2014-05-13 Abbvie Biotherapeutics Inc. Anti-TNF-α antibodies and their uses

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4180854A (en) * 1977-09-29 1979-12-25 Hewlett-Packard Company Programmable calculator having string variable editing capability
US4682189A (en) * 1978-05-31 1987-07-21 Purdy Haydn V Reproduction of character images, particularly for typesetting apparatus
US5005139A (en) * 1988-08-16 1991-04-02 Hewlett-Packard Company Piece-wise print image enhancement for dot matrix printers

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4180854A (en) * 1977-09-29 1979-12-25 Hewlett-Packard Company Programmable calculator having string variable editing capability
US4682189A (en) * 1978-05-31 1987-07-21 Purdy Haydn V Reproduction of character images, particularly for typesetting apparatus
US5005139A (en) * 1988-08-16 1991-04-02 Hewlett-Packard Company Piece-wise print image enhancement for dot matrix printers

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0569657A1 (fr) * 1992-05-15 1993-11-18 BULL HN INFORMATION SYSTEMS ITALIA S.p.A. Dispositif pour détection et correction d'imperfections dans des images digitalisées
EP0741041A3 (fr) * 1995-05-04 1998-01-21 SCITEX DIGITAL PRINTING, Inc. Technique de dispersion sélective de gouttelette
US8722860B2 (en) 2009-04-16 2014-05-13 Abbvie Biotherapeutics Inc. Anti-TNF-α antibodies and their uses

Also Published As

Publication number Publication date
AU8939391A (en) 1992-04-28
JPH06504652A (ja) 1994-05-26

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