Painting Pixel Values

From within the ROI Toolkit, you can directly change the pixel values in an image by "painting" with the mouse. This is done using the buttons shown below:

Once you have an image loaded, you can set the pixel value (intensity) to paint into the image in one of two ways:

• Pick the value from the current loaded image. Press the and move the mouse over to the displayed image. Click on an image intensity that you want to be set as the paint value.
• Manually enter the paint value. Press the button. You will see a pop-up for you to enter the paint value. The nature of the pop-up depends on the pixel data type of the current loaded image.
  • For integer-intensity images, you will see a dialog allowing you to set an integer value using a Spinner.
  • For floating-point intensity images, you will see a dialog allowing you to type in a new floating-point value.
  • For colour images, you will see a dialog allowing you to select a new colour using a colour-chooser.
  • For complex images, you will see a dialog allowing you to enter both real and imaginary component values.

Note: when you load a new image, the paint value must be re-selected. This is because the data type of the paint value depends on the data type of the loaded image.

To paint pixels, press the button. [Keyboard accelerator: point to the image and press the 'w' key.]. Holding the left mouse button down, draw on the image where you want to paint the pixel values. Double-click with the mouse to finish painting; press the "Esc" key to cancel the painting.

You can undo the last paint operation using the Undo from the ROI Toolkit's Edit menu, or typing Control-Z.

The width of the drawing pen is set using the selector, and is measured in screen pixels.

When you have painted the pixel values, be sure to save the image, or your changes will be lost.