Browse Prior Art Database

Creating Shaded Areas at 240 Pels/Inch that can be Scaled to 300 Pels Inch with Acceptable Fidelity

IP.com Disclosure Number: IPCOM000107256D
Original Publication Date: 1992-Feb-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 2 page(s) / 64K

Publishing Venue

IBM

Related People

Delaplain, BJ: AUTHOR

Abstract

This article discloses a method to shade a rectangular area using a raster image at a resolution of 240 pels/inch in such a way that a page containing such images can be printed on a 300 pel/inch printer with consistent shading. All areas shaded with the same gray level at the original resolution remain at the same level without gaps between images, i.e., shaded areas that were adjacent in the original resolution remain exactly adjacent.

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This is the abbreviated version, containing approximately 68% of the total text.

Creating Shaded Areas at 240 Pels/Inch that can be Scaled to 300 Pels Inch with Acceptable Fidelity

       This article discloses a method to shade a rectangular
area using a raster image at a resolution of 240 pels/inch in such a
way that a page containing such images can be printed on a 300
pel/inch printer with consistent shading.  All areas shaded with the
same gray level at the original resolution remain at the same level
without gaps between images, i.e., shaded areas that were adjacent in
the original resolution remain exactly adjacent.

      The shading program includes the steps of:
      1.   Padding the target image area left and right, top and
bottom with up to seven pels per side so that:
           a.   both the horizontal and vertical dimensions of the
image area are a multiple of eight; and
           b.   the image is offset a multiple of eight pels from the
top and left edges of the paper.
      2.   Starting the cell replication with a whole cell at the top
left of the adjusted image area and repeat horizontally and
vertically to fill the entire area.
      3.   Setting all bits to "0" that are within the boundaries of
the adjusted target area and outside the original boundaries of the
unadjusted target area.

      There is no rounding when the image offset is converted to
300ths of an inch because the offset is a multiple of eight bits.
Adjacent images' cell patterns are aligned before and afte...