# DPlngScan

### Scanning

This is the process of getting an image from paper into your computer. We can only deal with the computer side of the process here. You must have connected the scanner to your computer, maybe via the SCSI bus, USB, or possibly the printer port. The object you want to scan must have been inserted into the scanner, and the scanner switched on and made ready. Full details of this process should come in the documentation for the scanner.

The program controls scanners via a software interface called TWAIN. Before trying to scan anything, you must have installed TWAIN, and it must be visible to the scanning program. Just like !Fonts or !System, that means the !TWAIN directory, must have had a desktop window opened on it, or has been filer booted in some way, before you attempt to use it.

You must have a suitable TWAIN driver for the scanner you want to use.

Having completed the "obvious" steps above, this is a typical scanning session.

First load the scanning program by double clicking on its icon. It will install on the icon bar.

Next click on the icon bar icon with the left hand Select button on the mouse. A window will open.

Press the middle or menu button over the window. The main menu will appear. Follow the first entry 'File' to the right, and choose 'Select Source...' This will open the TWAIN manager source selection dialogue box. Click on the name of the source for your scanner, and then OK.

Now repeat the process of getting the main menu, but this time, choose 'Acquire...' from the file menu. The window for the source for your scanner will open.

The easiest thing to do, is to click on the 'Preview' button in this window. Preview will do a fast low resolution scan of what is in the scanner.

You should see an indication that the scanner is working, and hear it start to move. Eventually an image will appear in the window.

Now choose the bottom left tool in the tools pane at the left side of the main window. This is the rectangular selection tool. You can use it to mark off an area of the image in the window. In general many of the tools in this program can be applied to such an area. However, here we just want to use the tool to mark the area to scan.

Look at the preview scan, and decide which bit of it is of interest to you. Then drag on the area using the Select button. A rectangle will appear. Once you stop dragging, small 'handles' will appear on the rectangle. You can use the Adjust button to drag these handles and change the size of the rectangle. Dragging with Adjust in the middle of the rectangle will move it around. By dragging the rectangle in various ways, position it over the area that you want to scan.

For some scanners, at this point you will have to re-insert the medium being scanned.

Now again, choose 'Acquire...' from the File menu. This time when the TWAIN source window appears, choose the colour and resolution that you want for your final image. If you are scanning a photograph, you may choose 200dpi and 24bpp colour. For a page of text you want to copy or fax, 200dpi and black and white or 1bpp. You can easily repeat the scan to experiment with different value. Finally click on the 'Scan' button, again the scanner will start to work.

Probably after a longer delay than for the previous scan, you will see the finished image appear in the main window.

To save your image for future use, again get the file menu, but this time, follow the first entry 'Save' on it to the right. A window will appear in this there is a row of icons that allow you to choose the type of file. For the moment, select Sprite. By dragging the Sprite icon at the top of this save box to a disc window you can save the image.

This saving method is the same as for most RISC OS programs. As usual you can also save directly to other applications. Not all file types are suitable for such direct saves.

There are some keyboard short cuts to make the above process simpler. Shift F10 will open the TWAIN source selector, and if you only have one source installed, it is not necessary to go through this step. F10 will open the source window. Finally F3 will open the save box.

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DPlngScan is © David Pilling, 1993
Email:chris@chris-johnson.org.uk