Tutorial: AKVIS LightShop

Common parameters

In the left part of the AKVIS Lightshop's workspace under the Image Window common parameters (for the whole light effect) are set: Color, Opacity, Brightness, Scale, Angle and Blend Mode.

Let's look at every parameter in detail.

• Color. This parameter allows changing the color of the light effect. Activate a check-box near the color plate and select a color from the Standard Color Selection Dialog Box. Only the color changes; brightness and saturation of the light effect stay the same.

  Original colors	Blue color selected	Red color selected

  To call the Standard Color Selection Dialog Box it is enough to double click on the color plate. If you select a color, the check-box near the color plate will be activated automatically.

  To restore the original color of the light effect, disable the check-box.

• Brightness. This parameter allows reducing/increasing the original brightness of the light effect. The original brightness corresponds to 100%; if you set a value lower than 100%, the brightness increases, if you set a value larger than 100% – the brightness reduces.

  Brightness = 50%	Brightness = 100%	Brightness = 150%

• Opacity. This parameter sets the opacity of the light effect. The default value of the parameter is 100%, which means that the light effect is not transparent. If you reduce the value of the parameter, the light effect gets transparent. At 0% the light effect is invisible.

  Opacity = 40%	Opacity = 70%	Opacity = 100%

• Scale. This parameter allows scaling the light effect. The default value of the parameter is 100%. The higher the value of the parameter, the bigger is the light effect; the lower is the value, the smaller is the size of the light effect.

  Scale = 60%	Scale = 100%	Scale = 120%

• Angle. This parameter allows rotating the whole light effect. The values of the parameter lie within 0 and 360 degrees. The light effect rotates anticlockwise.

  Angle = 0	Angle = 45	Angle = 135

• Blend Mode. This parameter sets the way the light effect blends with the image. When you select a blend mode, the check-box Black background must be disabled. The program offers 8 modes; the default mode is Normal.
  • Normal – in this mode the light effect is applied to the image as it is.
    
  • Plus – in this mode the color and the opacity of the light effect and the image are summarized. When you apply a light effect on a black background, its original colors do not change; when you apply it to a white background, its colors become white; when you apply a light effect over any other color, the colors of this light effect get lighter.
    
  • Multiply - in this mode the color and the opacity of the light effect and the image multiply. As a result the color of the light effect gets darker. By multiplying any color on black, you get black; by multiplying any color on white, you get the original colors (they do not change).
    
  • Screen – it is a mode opposite to Multiply. In this mode the inverted values of the light effect and the image are multiplied componentwise. The resulting color is always lighter; black color of the background does not influence the color of the light effect, while white color converts any color to white.
    
  • Overlay - the calculation formula for the resulting color depends on the difference in brightness between the pixels of the light effect and those of the image. If the image is brighter than the light effect, the Screen mode is used; if the image is less bright than the light effect, the pixels blend using the Multiply mode. The neutral color for this mode is – 50% gray.
    
  • Lighten - in this mode the resulting color is made up of the highest values for every channel (RGB) of the two colors (that of the image and of the light effect). If the pixels of the light effect are lighter than the pixels of the image, they will not change; if they are darker - they are replaced with the pixels of the image. The neutral color for this mode is black; applying a light effect on white gives white.
    
  • Difference – in this mode the resulting color is calculated as a module of the difference between the color components of the light effect and the image. If a light effect is applied to a black background, the color of the light effect does not change; if a light effect is applied to a white background, the colors of the light effect get inverted.
    
  • Exclusion – this mode is similar to the Difference mode, but the resulting colors are less contrasting.
    

To change the position of the light effect in the image, just drag it with the left mouse button to a new place in the Image Window.

All changes made to these parameters are at once visible in the Image Window. The only exclusion are the parameters Scale and Angle that are applied automatically only if the check-box Autorun after Scale/Angle change in the Options is enabled (the dialog box Options is called with the button ). If this check-box is disabled, press the button to apply the change in scale.