Autodesk 62205-051408-9001 User Guide - Page 635

Setting the Range to Key Out ❚❘❘ To pull a key by extracting a custom color: 1. In the Keyer Controls panel, click Key. 2. Select Channel from the Keyer Mode list. The Channel controls appears. 3. Select Custom from the Channel Color list. 4. Click the picker, and click a point in the image to sample that color. You can also click and drag the picker across a region to obtain the average color of the pixels sampled. Try selecting different colors within the background area to get the best result. Note: To keep shadows, click just outside them. To remove shadows, click inside them. The sampled color appears in the color box. 5. Adjust the softness. 6. Adjust the Color Spread to extend the range of colors that is keyed out. Extracting a Range of Colors The second technique used to create a key is extracting a range of colors in the key-in image. Use this technique for clips where the color you are extracting contains impurities. To build a key by defining a color range, you can use one of several color models, each of which interprets the key-in image differently and gives a slightly different result. After setting the softness range, you set a range of colors to be keyed out. This is called the tolerance range. All pixels in the front image within the tolerance range are black in the matte. The tolerance range must not be too large or the edge of the composite will be too hard and the subject in the front image will appear to be pasted into the background. Once you choose a color model, you set a range of colors to become partially transparent to soften the transition between the front and back clips in the composite image. This is called the softness range. All pixels in the front clip within the softness range are gray in the matte. Selecting a Color Model Select one of the six color models from the Keyer Mode list: RGB, YUV, HLS, Channel, RGBCMYL, or Luma. For more information, see Keyer Mode. Trying Out the Different Color Models To determine which color model will give the best key, try creating a sample matte for each model. Each model operates independently of the others, except for the key color, which you can lock to one value for all color models. When you switch from one model to another, the values you set are retained, so you can compare the results easily. To try out different color models: 1. Make sure Animate is disabled. 2. In the Key controls, select a color model from the Keyer Mode list. 3. Click the Key Color picker. 4. Do one of the following: • Click on the image to sample a single color. • Click and drag the cursor over the area that you want to key out. The key color is set to the average of the pixels that the cursor samples. 619