How to use Scan2CAD

 

This topic outlines the basic steps you need to take to convert a raster image to vectors or a PDF file to DXF using Scan2CAD.

These steps may be all you need but if not, explore this Help to discover Scan2CAD’s full capabilities.

If you have any questions or problems, contact us!

 

See also the Real World Guide to vectorization, accessible from Scan2CAD’s Help menu. The Real World Guide tells you how to handle less than perfect scans and how to tweak vectorization settings. It will help you to get the best possible vectorization from any vectorizable image.

Click here to open it.

 

How to convert a raster image with no text

How to convert a raster image with text

How to create a color DXF file from a color raster image

How to convert a PDF file

 

How to convert a raster image with no text

Use this method if your drawing contains no text or the text is too poor quality to be vectorized using OCR.

 

The Warning: Color Image dialog appears when you load an image that contains more than two colors. These instructions assume that you have not turned the dialog off. If you have, you can reactivate it by selecting File Menu > Raster > Options > Color Display Warning.

 

1. Click to load an existing raster image or scan a drawing using File Menu > Acquire.
2. The Warning: Color Image dialog may appear. If it does:

 

a) Select the second option.
b) Click OK. You will enter Scan2CAD’s Simple Threshold dialog.
c) Move the slider to a position where the lines on your image are as solid as possible and the background is as clean as possible.
d) Click OK.

 

3. Work through the Raster Quality Checklist.

The most common reason for poor vectorization results is a poor quality raster image.

You must work through the Raster Quality Checklist even if you think your raster image is perfect.

Your image may look fine when viewed full screen but once you zoom into it and look properly you may find that it is not as good as you think.

 

If the raster image is good enough quality to vectorize:

4. Optional but recommended: Click to Smooth the raster lines.
5. Make sure the raster image is completely zoomed out by clicking .
6. Go to the Type Menu. This contains vectorization settings.

Choose the setting that best describes the raster image – Architectural, Electrical, Mechanical, CNC Profile, Site Plan or Contour Map.

If the raster image is a solid shape to be outlined, choose Outline.

7. Vectorize the raster image by clicking . Any text will be converted to short lines.
8. Optional: View the vectors by pressing V on your keyboard to view Vectors only, B to view Both vectors and the raster image together, Shift+F to Fade the raster image, C to toggle viewing vectors by Color or by type and G to toggle the display of Grab points at vector ends.
9. Save the vectors as a DXF file by going to File Menu > Vector > Save As.

 

Problems? See Scanning Checklist, Raster Quality Checklist, Troubleshooting vector recognition, Technical support

 

How to convert a raster image with text

Use this method if your drawing contains clear, sharp text characters.

 

The Warning: Color Image dialog appears when you load an image that contains more than two colors. These instructions assume that you have not turned the dialog off. If you have, you can reactivate it by selecting File Menu > Raster > Options > Color Display Warning.

 

1. Click to load an existing raster image or scan a drawing using File Menu > Acquire.
2. The Warning: Color Image dialog may appear. If it does:

 

a) Select the second option.
b) Click OK. You will enter Scan2CAD’s Simple Threshold dialog.
c) Move the slider to a position where the lines on your image are as solid as possible and the background is as clean as possible.
d) Click OK.

 

3. Work through the Raster Quality Checklist.

The most common reason for poor vectorization results is a poor quality raster image.

You must work through the Raster Quality Checklist even if you think your raster image is perfect.

Your image may look fine when viewed full screen but once you zoom into it and look properly you may find that it is not as good as you think.

 

If the raster image is good enough quality to vectorize:

4. Work through the Raster Text Quality Checklist.

Scan2CAD’s OCR text recognition will only recognize raster text where the following conditions are met:

 

The raster text is easily legible.
The raster text characters do not touch each other.
The raster text characters do not touch other drawing elements.
The raster text characters are not at different orientations.
The raster text characters are in a font that Scan2CAD can recognize.

 

Use the Raster Text Quality Checklist to ensure that your text meets these conditions.

 

If the raster text meets these conditions:

5. Optional but recommended: Click to Smooth the raster lines.
6. Go to the Type Menu. This contains vectorization settings.

Choose the setting that best describes the raster image – Architectural, Electrical, Mechanical, CNC Profile, Site Plan or Contour Map.

7. Tell Scan2CAD the size of text to expect:

 

a) Go to OCR Menu > Char Size.
b) Zoom into the biggest character on the image by placing your cursor over it and pressing the M key several times, until you can see the character clearly. You can also zoom in by scrolling your mouse wheel forwards.
c) Click on a black part of the character. It becomes enclosed in a box.
d) Click to zoom out.

 

8. Vectorize the raster image by clicking on .
9. Optional: View the vectors by pressing V on your keyboard to view Vectors only, B to view Both vectors and the raster image together, Shift+F to Fade the raster image, C to toggle viewing vectors by Color or by type and G to toggle the display of Grab points at vector ends.
10. Save the vectors as a DXF file by going to File Menu > Vector > Save As.

 

Problems? See Scanning Checklist, Raster Quality Checklist, Raster Text Quality Checklist, Troubleshooting vector recognition, Troubleshooting OCR text recognition, Technical support

 

How to create a color DXF file from a color raster image

The Warning: Color Image dialog appears when you load an image that contains more than two colors. These instructions assume that you have not turned the dialog off. If you have, you can reactivate it by selecting File Menu > Raster > Options > Color Display Warning.

 

1. Click to load an existing raster image or scan a drawing using File Menu > Acquire.
2. The Warning: Color Image dialog appears. Select the fourth option and click OK.
3. Go to Palette Menu > Reduce Colors Auto. Select a manageable number of colors, e.g. 32.
4. Go to Palette Menu > View/Edit Palette and group together similar colors:

 

a) Select all the shades of a particular color, e.g. all shades of red. You can do this by clicking on the colors you want to select in the palette on the right, by clicking on them in the Preview Window on the left or a mixture of both. (You may find this easier if you select the Hue option in the dialog.)
b) Click on .
c) Click on one of the colors you selected in (a). The Pick box changes to this color.
d) Click the Preview Change button. The colors you selected in (a) are changed to the color you selected in (c). You can see the change in the Preview Window.
e) Repeat (a) to (d) for all color groups on the image  – whites, blues, greens etc.
f) Click OK.

 

5. Press the U key to Unselect any selected color.

 

You now have two options:

 

Option 1. This option is better because it uses color information while vectorizing.
6. Go to Palette Menu > Select Color Layers. Click on the colors you want to vectorize, then click on OK.

 

Option 2. Use this if you were unable to group the colors cleanly in Steps 3 and 4 above.
6. Follow Step 3 onwards of How to convert a raster image with no text or How to convert a raster image with text, but just before you save the DXF file go to Vector Edit Menu > Modify > Vector Colors to Raster Colors.

 

Problems? See Scanning Checklist, Raster Quality Checklist, Raster Text Quality Checklist, Troubleshooting color reduction, Troubleshooting vector recognition, Troubleshooting OCR text recognition, Technical support

 

How to convert a PDF file

If you are loading vector PDF files and saving them as DXF, note that:
If File Menu > PDF > Import Options > Make Vector Arcs is selected, any vector PDF files you load will contain arcs. If Make Vector Beziers is selected, any vector PDF files you load will contain Bezier curves.
If File Menu > Vector > DXF Export Options > Vectors – > Color Layers is selected, PDF vectors will be saved to layers in the DXF file according to their color. The original PDF vector color will be mapped to the nearest color in the AutoCAD palette. If Vectors – > True Color is selected, PDF vectors will be saved in their actual colors but will not be saved to layers.

 

1. Click to load the PDF file.

The first page of the PDF file is displayed on the screen, along with the PDF Page Select dialog.

If the PDF file contains more than one page, use the Last and Next buttons in the dialog to select the page you want to convert.

Or, to jump to a known page in the PDF file, type the number of the page you want to jump to in the white page number box and then click Next.

2. A PDF page can contain raster entities, vector entities or both.

 

If the Raster option is selected in the PDF Page Select dialog, the page you have selected contains raster entities.

If you do not want to load the raster entities, deselect the Raster option.

When you deselect the Raster option, the raster entities are no longer displayed on the screen.

 

If the Vector option is selected in the PDF Page Select dialog, the page you have selected contains vector entities.

If you do not want to load the vector entities, deselect the Vector option.

When you deselect the Vector option, the vector entities are no longer displayed on the screen.

 

3. If the PDF page is the wrong way up, press the Rotate Ac button to rotate it anti clockwise, or the Rotate Cw button to rotate it clockwise.
4. Now:

 

If only the Raster option is selected in the PDF Page Select dialog:
a) Click Load.

 

If only the Vector option is selected in the PDF Page Select dialog:
a) Click Load.
b) Save the vectors as a DXF file by clicking or by using File Menu > Vector > Save As.

 

If the Raster and Vector options are selected in the PDF Page Select dialog:
a) Click Load.

 Once you have loaded the PDF page, you may or may not want to vectorize the raster image. In a PDF file containing both raster and vector entities the drawing – the bit you actually want to edit in your CAD program – is very often vector. The raster content is often a logo, a photograph or something similar that you do not want to edit.

 

 If you want to vectorize the raster image:

 Follow Step 2 onwards of How to convert a raster image with no text , How to convert a raster image with text or How to create a color DXF file from a color raster image. Note that the vectors that are created when you vectorize the image will be added to the vectors that were loaded from the PDF file.

 

 If you do not want to vectorize the raster image:

b) If the Warning: Color Image dialog is displayed, select the fourth option and click OK.
c) If you want the raster image to be loaded into your CAD program along with the vectors, go to File Menu > Vector > DXF Export Options and make sure that Attach Raster Image is selected.
d) Save the vectors as a DXF file by clicking or by using File Menu > Vector > Save As.

 

To convert a batch of PDF files, see Vectorize a batch of images.

 

Problems? See Troubleshooting PDF file loading, Technical support

 

Have questions on this topic? Talk to us