2 <effect tag="frei0r.lightgraffiti" id="frei0r.lightgraffiti">
3 <name>Light Graffiti</name>
4 <description>Light Graffiti effect.
5 <full><![CDATA[This effect allows to do Light Painting (i.e. painting with light sources on a photo by keeping the shutter
6 opened for a while), but for video.]]></full></description>
7 <author>Simon A. Eugster (Granjow)</author>
8 <parameter type="constant" name="longAlpha" default="0" min="0" max="256" factor="256">
10 <comment><![CDATA[Determines how the effect tries to adapt to background changes. <br/>
11 If the background does not change, then try to use 0 (requires the first frame to represent background only, without your light sources).]]></comment>
13 <parameter type="constant" name="lightOpacity" default="60" min="0" max="100" factor="100">
15 <comment><![CDATA[Basic opacity for a light source.<br/>
16 For slowly moving light source try to use a lower opacity value to obtain smoother results.]]></comment>
18 <parameter type="constant" name="opacitySmoothing" default="30" min="1" max="100" factor="10">
19 <name>Smoothing</name>
20 <comment><![CDATA[Smoothing of the light map according to the light source. <br/>
21 A value of 1 results in absolutely smooth transitions from background to light source, but might result in too weak lights. The maximum value gives sharper edges and stronger lights.]]></comment>
23 <parameter type="constant" name="backgroundWeight" default="0" min="0" max="100" factor="100">
24 <name>Background Weight</name>
25 <comment>Strength of the (calculated) background image. Setting it to 100 paints the light mask directly over the background, without any person in the image if the video starts with a «clean» background image.</comment>
27 <parameter type="constant" name="thresholdBrightness" default="450" min="0" max="765" factor="1">
28 <name>Brightness Threshold</name>
29 <comment><![CDATA[Determines how bright (<code>R+G+B</code>) a light source needs to be in order to be recognized as light source.<br/>
30 Increasing this threshold requires brighter light sources (i.e. more white or less color, respectively) but prevents some «false alarms» where semi-bright parts, e.g. hands where colors can change quite a lot compared to the background, are incorrectly recognized as light source.]]></comment>
32 <parameter type="constant" name="thresholdDifference" default="80" min="0" max="255" factor="1">
33 <name>Difference Threshold</name>
34 <comment><![CDATA[Similar to the brightness threshold, but for the brightness difference (<code>max(dR, dG, dB)</code>) <em>relative to the calculated background.</em><br/>
35 Increasing this threshold makes it harder for light sources to be accepted on bright backgrounds, but decreases the danger of noise counting as light source.]]></comment>
37 <parameter type="constant" name="thresholdDiffSum" default="0" min="0" max="765" factor="1">
38 <name>Difference Sum Threshold</name>
39 <comment><![CDATA[Threshold for the differences summed up (<code>dR + dG + dB</code>).<br/>
40 Raising this value might, in some cases, avoid that some light objects lit by the light source are added to the light mask.]]></comment>
42 <parameter type="constant" name="dim" default="0" min="0" max="255" factor="255">
44 <comment>Dims the light mask. Lights will leave a fainting trail if it is set to a value > 0.</comment>