When viewing images on your monitor with the idea of outputting them to a printer or other output device, you should make sure that gamma settings of your monitor are adjusted correctly. If your monitor is not calibrated correctly the image you see on screen will not be the same as that output by a printer.
The image sensor in a digicam is a linear device, this means that doubling the exposure doubles the output signal. When inputting a linear digital signal into a computer, the display on screen is non-linear and images tend to be darker with detail lost in shadow areas. This is because phosphors used in monitors are non-linear and make darker colors appear less dark and lighter colors extra bright. To prevent this the signal is electronically adjusted to counteract this effect. The monitor adjusts the input signal to boost dark areas and reduce light ones. This process is known as gamma correction and it ensures that camera and monitor working together produce a linear effect.
To get a faithful reproduction of your image you can adjust your monitor's gamma by using software supplied with your video card or through programmes such as Adobe Gamma supplied with Adobe Photoshop. Failing this you could check your own monitor settings by clicking the globe symbol at the top of this view.