Reading BRL-CAD .PIX and .BW Images into Adobe PhotoShop

First, you need to obtain a copy of the file you want to work with. Here is an example of how to get one of these files via anonymous FTP:

  ftp ftp.arl.army.mil
  anonymous       Give this as your USERNAME
  user@host       Give your E-mail address as the PASSWORD
  binary
  cd historic-computers/pix
  get first_four-w3793-n3009.bw
  quit

After obtaining a copy of the .PIX or .BW file, start Adobe PhotoShop (tm) on your computer.

On the File menu, select Open As.... The Adobe file selection window will pop up. At the bottom of that window, select the Raw format on the pull-down menu. Then find the file (first_four-w3793-n3009.bw in this example) in the file list displayed, and select it by double clicking.

The Adobe file selection window will disappear, and a Raw Options window will appear. Take the number after the -w from the filename (3793 in this example) and type it into the Width: entry box. Do this by moving the cursor into the box, clicking left-mouse, using the BACKSPACE key to delete the number that was previously there, and then typing in the proper number (3793 in this example). Do NOT press the RETURN or ENTER key at this time. Take the number after the -n from the filename (3009 in this example) and type it into the Width: entry box. For a BRL-CAD .bw file (as in this example), enter the number 1 (one) into the Channels: entry box. For a BRL-CAD .pix file, enter the number 3 (three) into the Channels: entry box. Ensure that the Header: entry box has the value of 0 (zero) in it. Then click on the OK button.

The Progress window should pop up, and the progress bar will be displayed for a while.

When the image has been loaded, it will appear upside-down, because BRL-CAD uses "First Quadrant" pixel addresses, and PhotoShop uses "Fourth Quadrant" pixel addresses. This is easy to correct. On the Image menu at the top of the main window, select the Flip --> item and while continuing to hold the mouse button down, pull the mouse right to further select the Vertical item before releasing the mouse.

The image will now be properly displayed, and is ready for incorporation into your own documents.

This is a good time to write the image out as a native PhotoShop (".psd") file. On the File menu, select Save As.... The Adobe file selection window will pop up. At the bottom of that window, select the PhotoShop format on the pull-down menu. Then type the new name for this image into the Save this document as: entry box, and click on the Save button.

Check out my Photographs of Historic Computers collection for some images to practice on.


Mike Muuss