| FAQ - Frequently Asked Questions
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| What are
the benefits of converting legacy drawings?
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| What is
manual redraw? |
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| What is
heads-down digitizing? |
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| What is
heads-up digitizing? |
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| What is
a Scanned Raster Image Drawing? |
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| What is
a Vectorized CAD drawing? |
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| What is
auto-vectorization? |
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| What
are the benefits of converting legacy drawings?
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Drawings which are redrawn
into vector formats, producing intelligent
objects and complying with your company's
current CAD standards, can streamline the
drawing change process that enables critical
resources to perform more value-added work.
Many companies have found that their legacy
drawings contain critical resource information
which cannot be efficiently retrieved from
drawings that consist of paper or even raster
images. Our Redraw provides you with the
ability to data-mine your drawings for
information using text search engines, browsers
and various other tools that link drawing
data to relational databases, thus improving
the efficiency of your operations by 20-30%.
Some of our clients maximize their return
by having us redraw only those legacy drawings
that are candidates for engineering changes
or reviews due to projects and work orders
that are scheduled to be released during
the upcoming year; others have us redraw
selected legacy drawing simply in order
to obtain the benefits of efficient information
retrieval. |
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| What
is manual redraw? |
Manual redraw uses the
cognitive skills of a human operator to
recognize and control the construction of
each object within a drawing. The simplest
(and most common) way to perform manual
redraw on a paper drawing is by visual take-off
from the paper drawing into the computer
using CAD software and operator initiated
commands and placement. All manual redraw
techniques rely heavily on the human operator
to control the redrawing process and this
results in highly accurate drawings which
are required for further processing like
transferring of data to CNC for machining.
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What
is heads-down digitizing? |
| Heads-down digitizing is a labor intensive
manual redraw process where an operator hand-digitizes
vertices (i.e. points) from a paper drawing
taped to a digitizing board and then executes
CAD commands to redraw the lines and arcs
and retype the text. |
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What
is heads-up digitizing? |
Heads-up digitizing is
a third form of the manual redraw process
where the paper drawing is first scanned
into a raster image and then displayed on
a computer screen. The drawing is redrawn
into vector format using software that traces
vector lines and arcs on top of the raster
image background. The software normally
pauses at intersecting lines and waits for
the human operator to initiate a command
based on the operator's cognitive decision.
This method is called heads-up digitizing,
tracing or overlaying. With a trained operator
it can be faster than other manual redraw
methods. |
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What
is a Scanned Raster Image Drawing? |
| A scanned raster image
is a digitized image of a drawing taken
either from a paper copy or microfilm copy
of the drawing. A scanned raster image places
small black dots, called pixels, where it
recognizes a contrast between the normally
white paper background and the pencil or
ink markings. A typical drawing can have
millions of small black dots, or pixels,
representing these markings. This technology
is similar to making a Xerox photocopy on
paper using an office copy machine, a process
that most of us are familiar with. The main
differences are that drawings can be much
larger than the 8-1/2"x11" paper and instead
of placing the image immediately on a blank
piece of paper, a digitized image is placed
in a computer file that can later be viewed,
edited and printed by a computer program.
Normally each of these dots is one color
(black) and raster files can get very large
if uncompressed. If color is added to each
dot, these raster files can become exceedingly
large even when compressed. |
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What
is a Vectorized CAD drawing? |
| A vectorized CAD drawing
is a computer file that represents a drawing
using more intelligent data than dots or
pixels. This data can be used to distinguish
between line segments, arcs, points, circles,
text and color. Vectorized drawings can
also define even more intelligent objects
by defining collections of lines, arcs,
circles and text as objects called symbols
or blocks. The real power of CAD is derived
from its ability to define and manipulate
large numbers of scalable, reusable objects
and most CAD drawings require more than
simply pixels, lines and arcs. Virtually
all CAD and graphic illustration software
defines image data as vectors because of
the associated precision, the capability
of rapid processing of vector objects, and
operator ease with regard to modifying these
images. |
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| What
is auto-vectorization? |
Auto-vectorization is
a process performed by a software program
on raster images of drawings to convert
them to vectorized lines, arcs, circles
and sometimes other primitive shapes such
as arrowheads, solids and text. Most auto-vectorization
programs can be run interactively by an
operator or unattended using a configuration
file that provides some limited control
of the vectorizing process. Although the
auto-vectorization technique is usually
less costly than the manual redraw technique,
the quality of the finished drawing is not
comparable to other CAD drawings. The typical
auto-vectorization replaces a lot of little
dots with a lot of short lines and arc segments.
Extensive manual labor is usually required
to make the many corrections required in
an auto-vectorized drawing. |
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