CompactDraw Basics

Mating - Transparent Color/Intensity, Paint Transparency/Opaque

As a good designer you would like to use a clipart photo object your project. The photo objects are usually photographed on solid (white) background. If you make the background color of the photo transparent you can compose the photo to your project and/or use drop shadow or other effects to spice up the image.

There are few tools to turn the background of a image transparent. If the background of the image is not a solid color you can use the technique described in the Masking Bitmap.

The tools you would like to use are:

Note: if you select the Bitmap object and the tools are disabled - it means the Bitmap is transformed (rotated, resized..). You have to use Reset Transformation to return the bitmap to its normal state and then you can use the Mating tools. This is because we would like to achieve the maximum quality.

Paint Transparency/Opaque
First two tools are manual painting tools. They are just very simple tools to paint transparency or opaque. You can set the width and the intensity of the brush.
The tools are great final touch if you first create the transparency with the Color or Intensity Transparency tool and then you want to fix the small areas.

Color Transparency
This is a smart process to make one color transparent. After you click this tool, you can select the tolerance. Higher tolerance - more similar colors to one selected will be selected as transparent. The tool lets you to select the color on the photograph with the Color Picker tool.
Color Transparency does a lot of hidden procedures to alias the output and put a special semitransparentcies at the edges. Thanks to this the results are much better than results you would achieve with other software tools.

Here is an example of the butterfly on white background photography. We used the Color Transparency tool and select the background white color. The result is good enough so we can put a drop shadow and it looks perfectly real.

Intensity Transparency
The Transparency is calculated from the intensity. More intensity - more transparency. This means this works on images on white background (unless you want a special effect). The Intensity Transparency uses a different alghorytm than the Color Transparency.

You always can use combination of all the tools to get an great effects.
Here is an example:

  • We used a photography of the car on white background from the clipart collection.
  • Using Intensity Transparency we create the image in the middle. However because there were other white areas like headlights, plate or inner wheels they get transparent as well.
  • Now with Paint Opaque we paint on the areas we want to turn non transparent - we painted on wheels, plate and headlights.

The result is object with fair transparency