Open up your image in PSP. This looks better with photos.
Go to ‘Effects’ > ‘Texture Effects’ > ‘Blinds’, and change your settings to these:
You can change the colour of your scanlines or the opacity if you like. All you have to do now is save your image.
You can also check the box which says ‘Vertical’ instead of ‘Horizontal’ to have your scanlines going down.