1.6   Creating and saving new images

When you have selected an image region, you may want to save it for later use, for further study at a later stage, or for use in reports etc. Here you will learn how to do this.

Creating a new image from a selection

The first step in turning a region of interest into a new image is to select it; you did this using Box Selection in the previous page of the tutorial (section 1.5). The selected area will be surrounded by a square box in the image window.

Note: If no box is visible on your January 1997 image, you must return to section 1.5 and make the selection again before continuing.

Having selected the area of interest you must now copy it onto the Windows clipboard. This can be done in several ways:

From the menu bar:
  - either click on Edit, then Copy on the drop down menu,
  - or hold down the [ALT] key and type [E], then type [C].
Mouse shortcut:
  Click on the Copy Icon - .
Keyboard shortcut:
  Hold down [CTRL] and type [C]. (Shorthand: [CTRL+C] ).

You can tell that the selection has been successfully copied when the paste icon on the toolbar lights up, changing from dull grey - - to colours - .

To create a new image it is not sufficient just to paste selection onto the Bilko window. Instead you must open a new image file. Again there are a number of ways to do this:

From the menu bar:
  - either click on File, then New on the drop down menu,
  - or hold down the [ALT] key and type [F], then type [N].
Mouse shortcut:
  Click on the New File icon on the toolbar - .
Keyboard shortcut:
  Hold down [CTRL] and type [N]. (Shorthand: [CTRL+N] ).

Any one of these options will bring up the New dialog ( figure (5K)). This gives you a list of different document types, with the type currently selected marked in blue. You are creating a new image document, so select this option (click on it with your mouse, or use the keyboard down arrow). Finaly press OK to open the new image document.

You should now have a new image document called atsr1997.gif From (40,120) To (219,239). Pull down the grey bar at the top of this image doucment.

Saving a new 8-bit image

You can save the new image as a separate file in Bilko. As the original image was an 8-bit grey-scale GIF image, you can use this format to save the new image without losing any of the information. As always there are several ways to do this.

From the menu bar:
  - either click on File, then Save on the drop down menu,
  - or hold down the [ALT] key and type [F], then type [S].
Mouse shortcut:
  Click on the Save icon on the toolbar.
Keyboard shortcut:
  Hold down [CTRL] and type [S]. (Shorthand: [CTRL+S] ).

The Save As dialog will appear. figure (5K)). The dialog alows you to select

• the folder (or directory) to save in - the default will be the folder you last worked with, in this case likely to be 'tutorial_data'. You can change this if you wish, by using the drop down arrow on the right of the folder box to find a new folder.
• the file name - the default includes the original name and the coordinates of the selection. If you prefer a shorter name you can change this, but for the time being, accept the default.
• the file type to save as - in this case the default is GIF, suitable of 8-bit images, and a format accepted by web browsers. To see the other formats available use the arrow on the right to open the drop-down.

Accept the defaults if possible, and close the new image.

Note: If you are working on a network, you may have to change the Save in option to a folder where you have write-permissions. The file name and file type should not have to be changed.

After having closed the image, open it again ( [CTRL+O] ) and pull down the grey bar at the top of the image window as explained in T.1.2. Notice how the image has been saved with the extract coordinates. This is particularly useful if you want to choose a different filename for the new image.

Saving an 'extracted' image

You will now save the subarea of atsr199801.gif which you opened earlier using the extract dialog.

1. Activate the image by clicking on it.
2. Notice that the Save icon on the toolbar is not available for this image, and if you try the keyboard shortcut you used above ( [CTRL+S], nothing happens. This is to prevent you over-writing the original image with the reduced version.
3. Instead open the File menu and select Save As (key strokes [ALT+F] > [A] ).
4. Fill in the Save As dialog in the same way as you did for the 1997 image.

Screenshots: Saving an image display with colour bar

When you save an image in Bilko, the colour bar at the bottom of the window is not included. Like the scroll bars and the image control bar, the colour bar is part of the image window, not of the image itself. However, for some of your work you may want to include a colour or grey-scale so that others can relate the colours in the image to the numerical values representing the geophysical parameter you are working with.

You can do this by taking a screenshot of the Bilko application window and editing it in a picture editing program such as Photoshop or Paintshop Pro..