Many PDF files contain circles and arcs that are exploded into polylines. These polylines tend to be imprecise making it difficult to detect them as a circle or arc.
Although the recognition of a polyline as a circle or arc appears to be easy when one looks at a PDF (a person can immediately recognize the circle or arc), however for a software to have this same type of recognition takes a lot more effort.
Graphic: Circle in Polyline Segments
Many internal parameters were set, but there is no need to disclose all of my secrets! The recoginition process works well in providing true circles. If this is not the case with your file then it was because of the lack of polylines, but the precense of a chain of line segments.
The user can set one parameter, which is the deviation of the polyline vertexes from the radius of the circle. The parameter is set in % of
the radius formula.
For this you must use your intuition and experience to determine what the best parameter may be for the specific file.
To generate arcs from polylines, now this is a very difficult task, but not impossible. The radius of arcs is subject to an internal limitation, because otherwise straight lines could be converted into arcs with a large radius. The angle alpha of the generated arcs are limited to at least 20 degrees. The convexity of arc W is also subject to restrictions. If a polyline is not converted into an arc, then it simply did not meet our internal minimum requirements.
Important!!
When a conversion generates arcs upside down, then the radius deviation
R in % was set too high.
Graphic: Internal Arc Parameters in Print2CAD
Color Palette of the DWG or DXF Files
Print2CAD allows the user to assign the RGB values of the colors used in a PDF into the resulting DWG or DXF elements.
Important!
The color Black in a PDF is converted into the color White in RGB. The color White in a PDF is converted into the color White in RGB.
It is possible you are working on a white background with white elements if your converted file doesn't show any detail on the screen.
White on white will not plot nor print.
Our suggestion for a solution is simply activate the option “Assign 10 Index Colors” before converting your file.
Definition of RGB color space:
"An RGB color space is any additive color space based on the RGB color model. A particular
RGB color space is defined by the three chromaticities of the red, green, and blue
additive primaries, and can produce any chromaticity that is the triangle defined by those
primary colors. The complete specification of an RGB color space also requires a white
point chromaticity and a gamma correction curve. RGB is an acronym for Red, Green,
Blue. An RGB color space can be easily understood by thinking of it as „all possible colors“
that can be made from three colourants for red, green and blue. Imagine, for example,
shining three lights together onto a white wall: one red light, one green light, and one
blue light, each with dimmer switches. If only the red light is on, the wall will look red.
If only the green light is on, the wall will look green. If the red and green lights are on
together, the wall will look yellow. Dim the red light some and the wall will become more
of a yellow-green. Dim the green light instead, and the wall will become more orange.
Bringing up the blue light a bit will cause the orange to become less saturated and more
whitish. In all, each setting of the three dimmer switches will produce a different result,
either in color or in brightness or both.
An LCD display can be thought of as a grid of thousands of little red, green, and blue light
bulbs, each with their own dimmer switch. The gamut of the display will depend on the
three colors used for the red, green and blue lights. A wide-gamut display will have very
saturated, „pure“ light colors, and thus be able to display very saturated, deep colors. (...)“
Source: Wikipedia, subject "RGB color space"
License Agreement: http://creativecommons.org/licenses/by-sa/3.0/
Print2CAD allows the user to assign the index colors based on AutoCAD index color table to all DWG or DXF elements.
255 AutoCAD index colors are most frequently used in DXF or DWG files. An advantage of this is both colors black and white are defined as color nr. 7. Therefore when working on a black background, the color nr. 7 will be defined as white and vice versa when working on a white background.
Print2CAD allows the user to assign the 10 basic index colors, based on AutoCAD index color table, to all DWG or DXF elements.
| Index | Color |
| 1 | Red |
| 2 | Yellow |
| 3 | Green |
| 4 | Cyan |
| 5 | Magenta |
| 6 | Blue |
| 7 | White |
| 8 | Dark grey |
| 9 | Light grey |
| 10 | Red |
Assign Uniform Color to All Elements
Print2CAD allows the user to assign a uniform color to all converted elements.
