Converting vector PDF files to TIFF or BMP

(See also Converting PDF files to CAD.)

There are a number of programs available that can convert PDF files to TIFF or BMP. Two - Photoshop and Omniformat - are described below. Omniformat is free but displays sponsor pages.

Using Photoshop to convert PDF files to TIFF or BMP

The instructions below have been written for Photoshop CS but may also work with other versions of Photoshop.

  1. Load your PDF file into Photoshop by going to Photoshop's File Menu and choosing Open.

    If you have loaded a PDF file containing vector drawings, a dialog called Rasterize Generic PDF Format appears.

    In the Rasterize Generic PDF Format dialog:

    • Leave the Width and Height figures at Photoshop's defaults.
    • Set Resolution. 300 pixels/inch is good for most line drawings, but if the drawing is small (like a logo) you may need to try a higher resolution.
    • Set Mode to Grayscale.
    • Switch off the Anti Aliased option.
    • Click OK. The PDF file will appear in Photoshop.
    • Zoom into the file and inspect it. If it is broken, or you can’t read the text as in the examples below, the resolution is too low and Scan2CAD will not be able to vectorize the image well. In this case, close the image and load it into Photoshop again, this time choosing a higher resolution.

      Too low res image     Too low res image

  2. Go to Photoshop's Image Menu > Mode.

    If the Bitmap option is not ticked, click on it. Then:

    1. Click OK to the Flatten Layers prompt that appears.
    2. A dialog called Bitmap appears.
    3. Leave the Output Resolution at default.
    4. Set the Method to 50% Threshold.

    5. Click OK.

    This converts the image to monochrome (2 colors).

  3. Save the file in TIFF format.

    In the TIFF Options dialog set Image Compression to None.

  4. Load the TIFF file into Scan2CAD by starting Scan2CAD and clicking .

    You can now vectorize the TIFF file in the same way as any other raster image.

Using Omniformat to convert PDF files to TIFF or BMP

Downloading and installing Omniformat
Using Omniformat
A note about resolution

Downloading and installing Omniformat

  1. Go to http://www.omniformat.com/download.html.

  2. Click on the Omniformat Download link and download Omniformat (omniformat.exe) to your hard drive.

  3. In order to use Omniformat you will also have to download its sister product PDF995 and the PDF995 printer drivers. (PDF995 is a PDF file creator and is a useful program in its own right.)

    To download PDF995 and the PDF995 printer drivers click on the PDF995 Download link. This will take you to another web page.

    Download the PDF995 Printer Driver (pdf995s.exe) and the Free Converter (ps2pdf995.exe) to your hard drive.

  4. You should now have three files on your hard drive - omniformat.exe, pdf995s.exe and ps2pdf995.exe. Install them in the following order:

    ps2pdf995.exe
    pdf995s.exe
    omniformat.exe

Using Omniformat

Once you've successfuly installed Omniformat you are ready to turn a PDF file into a raster image suitable for Scan2CAD to convert.

Do the following:

  1. Go to Start > All Programs > Software995 > Omniformat.

    Sponsor page messages and sponsor pages will appear. Once you have passed these, the Omniformat dialog appears.

  2. Select BMP Microsoft Windows bitmap image from the Output Format dropdown.

  3. Click the Options button.

    The Options dialog appears.

    1. Select an appropriate resolution value (see A note about resolution below).

      We suggest 300 for most drawings.

    2. Click OK to exit the Options dialog.

  4. Click the Start Monitoring button.

  5. Use Windows Explorer to copy a PDF file into the Watch Folder specified in the Omniformat dialog. By default the Watch Folder is at c:\program files\omniformat\watch.

    VERY IMPORTANT: Omniformat will delete the PDF file from the Watch Folder once it has converted it so it is important that you COPY the PDF file you want to convert into the Watch Folder. DO NOT put the original there.

    Omniformat will automatically convert the PDF file to BMP.

    (Note: You can convert several PDF files to BMP at once by copying more than one PDF file into the Watch Folder.)

  6. Load the BMP file into Scan2CAD by starting Scan2CAD and clicking .

    Omniformat creates 256 color BMP files, so the Warning: Color Image dialog may appear. If it does, select the second or third option and click OK. If the Warning: Color Image dialog does not appear and your BMP file only contains black and white colors you can reduce the size of the file by decreasing its color depth. To do this, go to Scan2CAD's Palette Menu and choose Reduce Color Depth > 1 Bit [Mono].

    You can now vectorize the BMP file in the same way as any other raster image.

A note about resolution

Omniformat allows you to select a raster file resolution. The correct resolution will depend on your drawing and you may have to experiment with different resolutions to find the best one for your PDF files.

When you have loaded the BMP file that Omniformat has created into Scan2CAD, zoom into it and take a look.

If it is broken, or you can't read the text as in the examples below, the resolution is too low and Scan2CAD will not be able to vectorize the image well.

Too low res image     Too low res image

In this case, use Omniformat to create the BMP file again, this time using a higher resolution.

Unfortunately, the highest resolution Omniformat will convert to is 300 dpi. This may not be enough for all drawings.

A word of warning

You should be able to convert any file up to A0/E paper size (48x36 inches or 841x1189mm) using Omniformat's maximum resolution of 300 dpi.

If the paper size of your PDF file is larger than this, use a lower resolution. This is because attempting to create a BMP file from a large PDF file can create a BMP file many hundreds of Megabytes in size. This can choke your PC.

You can tell what paper size your PDF file is by loading it into Acrobat Reader. The file's width and height will be displayed at the bottom left of the Acrobat screen (you may need to pass your mouse over the bottom left of the screen to see them).

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