System and method for digital rendering of images and printed articulation

A system for varying a tip size of an implement having contact with a surface in response to a real-time-varying means, said real-time-varying means being under manual control, for producing strokes or marks of said implement which exhibit varying stroke or mark width, wherein said strokes or marks are produced in a two-dimensional image field on a computer, said system comprising the steps of:

• computing a set of implement tip height field arrays which vary from a minimum desired implement tip width to a maximum desired tip width, said widths being spaced evenly and are represented as an array of two-dimensional height fields, each two-dimensional height field being a separate representation of an implement tip height fields of a given width and having individual horizontal and vertical subpixel offset,
• varying the desired width of said implement tip in response to said real-time-varying means under manual control,
• selecting an implement tip height field array whose width most nearly approximates said desired implement tip width,
• applying said implement tip height field array, and
• modifying spacing of contact marks so that said contact marks are spaced apart by a distance proportional to an average of the widths of said contact marks, so that strokes or marks made by said implement may exhibit varying widths.

A method for sequencing and rendering marks of contact between an implement tip and a surface for producing strokes or marks of said implement onto said surface, said strokes or marks being continuous, smooth, and without visible artifacts, said strokes or marks being rendered for the purpose of simulating accurately the strokes or marks occuring in the use of natural media, wherein said strokes or marks are produced in a two-dimensional image field on a computer, said method comprising the following steps:

• computing a two-dimensional array of two-dimensional height fields, said array of height fields representing renderings of the said implement tip, each said rendering representing a separate horizontal and vertical subpixel offset, the number of said renderings being a function of the width of said implement tip,
• evaluating a set of placement positions for the rendering of marks of contact, said positions being regularly spaced along said strokes, said spacing being calculated as a percentage of the current width of said implement tip, said positions being measured at subpixel accuracy,
• designating, for each of said placement positions, a height field from said two-dimensional array of height fields which corresponds most closely with said horizontal and vertical subpixel offsets of said placement position,
• subtracting, for each of said placement positions, said horizontal and vertical subpixel offsets from said placement position to yield an integer horizontal and vertical pixel offset within said two-dimensional image field, and
• overlaying, for each of said placement positions a corresponding designated height field at said integer horizontal and vertical pixel position, to render said marks of contact between said tip and said two-dimensional image field, said designated height fields being used as a plurality of donor tip deposit fractions.