public void setOpacity(String opacity) {
        this.opacity = opacity;
    }
<p>
A percentage that indicates how much you want a watermark to obscure the video in the location where it appears.
Valid values are 0 (the watermark is invisible) to 100 (the watermark completely obscures the video in the
specified location). The datatype of <code>Opacity</code> is float.
</p>
<p>
Elastic Transcoder supports transparent .png graphics. If you use a transparent .png, the transparent portion of
the video appears as if you had specified a value of 0 for <code>Opacity</code>. The .jpg file format doesn't
support transparency.
</p>

@param opacity
       A percentage that indicates how much you want a watermark to obscure the video in the location where it
       appears. Valid values are 0 (the watermark is invisible) to 100 (the watermark completely obscures the
       video in the specified location). The datatype of <code>Opacity</code> is float.</p>
       <p>
       Elastic Transcoder supports transparent .png graphics. If you use a transparent .png, the transparent
       portion of the video appears as if you had specified a value of 0 for <code>Opacity</code>. The .jpg file
       format doesn't support transparency.
aws-java-sdk-elastictranscoder/src/main/java/com/amazonaws/services/elastictranscoder/model/PresetWatermark.java