Logo
Conversion

 

Conversion Explained...

IJCAD Services can quickly and efficiently convert drawings into editable CAD files.

For paper drawings, the process is commonly referred to vectorising and involves four basic phases.  Each phase builds on the one before.

1. Scanning of paper drawing.

Scan the paper drawing into a bitmap image format suitable for use within the next phase of the conversion.  This is usually the same process as scanning an A4 document sheet, but the scanner used is much larger. IJCAD Services contracts a third party to undertake the actual scanning of the drawing sheet(s).

2. Cleaning the image.

Depending upon the condition of the paper print, the quality of the scan could introduce several imperfections which degrade the image quality. Imperfections such as “hairy lines”, “speckles” and “holes” are probably present.  To improve the quality of the finished product, such imperfections should be reduced to a minimum, preferably removed altogether.

3. Converting to vector.

The process of converting to vector takes the image and uses a series of algorithms to scan and recognise the lines, circle, dimensions and text that make up the drawing. IJCAD Services using Softcover’s Scan2CAD v7. See the Softcover website for a description of the Scan2CAD software.

4. Editing/correcting vector.

Unfortunately, any conversion software is not 100% accurate.  Often because of the quality of the original print, entities are not converted correctly.  Common errors involve; line types may not be recognised because of the line breaks, arcs and circles may not be recognised due to corruption of aspect ratio, often text contains serial or part numbers or specific field of expertise related wording.

The two main factors which affect the suitability of a paper print for conversion into an editable CAD files are:

  • Quality of the paper print. If the paper print has much of the detail smudged, dirtied or is in general difficult to read, the image of the paper print will also contain these imperfections. Any practical attempt to clean the image will be limited.
  • Closeness of parallel lines. If the paper print has a number of lines very close together, the process of cleaning the image may cause some of the lines to merge or disappear depending on the setting of the cleaning process.