6. Add Logos and Still Images

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Many organizations place their logo over all videos, which is typically called a watermark. Most editing programs except for Microsoft's Movie Maker 2, which doesn't offer this function allow you to do this fairly easily.

Most programs use a feature called "overlay" or "chromakey" to superimpose the still image over the background video; I explain this fully in Chapter 6. As they relate to video, chromakey and overlay can get pretty complicated. However, using these techniques with still images is simple.

To use chromakeying, produce your logos over a solid blue background. I'll show you how to achieve this in a moment. Alternatively, if you know how (or if a graphics artist is creating the logo), save the logo as a 32-bit TGA (Targa) file with a transparent background alpha channel.

Briefly, an alpha channel specifies which portion of the image should be transparent when merged with another image or video. With a logo file, you (or your graphics artist) would designate the background of the image as transparent, so when merged with the video file, all but the logo will disappear.

To insert the logo into your video project, drag it onto a separate video track above the main video track, (shown in Figure 5.23). As with titles, typically, you adjust duration by dragging the right edge of the logo to make it longer or shorter. If your program doesn't have multiple video tracks, check documentation for "adding logos" or "overlaying still images" onto your video.

Figure 5.23. To insert your logo in a prosumer editor, drag it to a track above the video.


If you create a 32-bit image with an alpha channel, most video editors will recognize that you want the background eliminated, and do this automatically. If you create an image with a blue or black background, after placing the image on the timeline, you'll see the logo with background superimposed over the video, as you see on the left in Figure 5.24.

Figure 5.24. After applying the chromakey filter, use an eyedropper or similar tool to select the background color to eliminate.


To eliminate the background, use the chromakey filter, (which I'll explain in the next chapter) program controls to apply the video editor's chromakey filter to the logo. At a high level, these tools work by eliminating a color from the top video and inserting what's not eliminated into the background video. Operationally, the first step is to identify the color you want removed from the logo, typically using an eyedropper or similar tool like that shown on the left in Figure 5.24.

With still images, the background is perfectly consistent, so selecting it with the eyedropper usually makes the background disappear immediately. If not, find the filter's "similarity" or "color tolerance" adjustment, which expands the range of colors excluded by the chromakey filter. Increase the tolerance control slightly and the background should completely go away.

Once you've eliminated the background color, use the program's two-dimensional (2D) motion controls to shrink the image to the desired size and move it to the target location, making sure that you're within the Action Safe region. To make the image translucent, find the program's transparency control and adjust it to the target value. A translucent logo is shown on the image on the right in Figure 5.25.

Figure 5.25. Logo, after shrinking and moving to the right bottom corner (left), and then adjusting the transparency values (on the right).


Adding Full-Screen Images to Video

Virtually all video editors can import digital images and convert them to video. This includes not only digital pictures and logos, but also the output of programs such as PowerPoint, Visio, AutoCAD, and other electronic design programs. Adding images to video is a great way to explain your work or product and can help break up otherwise monotonous talking-head footage.

Adding still images to your editor is also fairly simple. Generally, you drag them down to a video track and grab the right edge to set duration. Most programs let you add transitions between still images and adjust color, brightness, and similar values with the same filters available for video.

However, when adding line art and other finely detailed images, you must keep several critical points in mind. First, the resolution of video is limited. Even a high-quality format like MPEG-2 (used in DVD) has a resolution of 720x480 pixels, while streaming files are often produced at 320x240 pixels. Suppose you included a high-resolution image such as an architectural drawing produced in AutoCAD 2004 shown in Figure 5.26.

Figure 5.26. Output from AutoCAD 2004.


The image has a resolution of 1,340x960. If you're encoding for DVD at 720x480 resolution, there aren't enough lines of pixels in the video file to display all the pixels in the image. To convert from the 1,276x820 source to the 720x480 output during encoding, the video editor will discard image detail, degrading image quality.

Plus a television set's inability to display fine details with accuracy only compounds the problem. Basically, it's almost impossible to display high-resolution images in a video file without losing detail.

To workaround, cut your image into smaller chunks as shown in Figure 5.27. Then, import the files into your video editor and display them in the desired order.

Figure 5.27. To show a high-resolution image, display it in chunks.


You can do this in two ways. First, divide the image up into separate images each containing the desired views using an image editor like Ulead's PhotoImpact or Adobe Photoshop. When using this approach, keep the following rules in mind:

  • For best results, make sure each image has an aspect ratio of 4:3, meaning four horizontal pixels for every 3 vertical pixels. Figure 5.27, for example, includes chunks of 320x240, 640x480, and 400x300, all of which adhere to the 4:3 ratio. The easiest way to calculate this is to divide the number of horizontal pixels in the image by four, then multiply by three to produce the desired vertical resolution.

  • Also, make sure each image has a lower vertical resolution than your target output. If producing for DVD, this means less than 480 lines of resolution.

  • After you input each image file into your video editor, use 2D image controls to zoom the image to full screen, making sure that you zoom proportionately, meaning equally on both the horizontal and vertical axis. Otherwise, you could distort the image.

Using 2D Controls to Scan Around the Image

As you become more familiar with your video editor, you'll find the easiest way to show portions of an image is to insert a high-resolution version into the video editor and use the editor's zoom and positioning controls to show only the desired region of the image. Take a mental break for a second, and I'll explain the procedure.

Imagine you were at Mount Rushmore with your camcorder. You stand in one spot and zoom in to shoot George Washington, where it all began. Then you zoom out to show President Washington with President Jefferson. Then you zoom back in and pan across to President Lincoln, then President Roosevelt.

Obviously, the magnificent carved mountain is there the entire time; you're just using the camera's zoom controls to zoom in and out and your own two-dimensional positioning controls (hands and arms) to move the camera around the mountain. Most video editors have controls that work the same way, allowing you to pan and zoom around high-resolution images to show only low-resolution sections.

Once you've imported the image into the editor, you can zoom into and out of the image with magnification controls, and pan around the image using positioning controls. The only segment of the image the editor will include in the rendered video appears in the viewport; the other regions of the image are still there, but out of camera.

This is illustrated in Figure 5.28; the black area is the viewport, and the gray regions are out of the camera's current scope. Basically, you drag that portion of the image to display into the viewport, and use zoom controls to zoom into or away from the image.

Figure 5.28. Two-dimensional (2D) editing controls allow you to show different regions of an image at different magnification levels.


The only caveat is to keep the viewport smaller than the output resolution of the video, just as you did for each subset of the image you isolated in your image editor. The image editor will automatically set the viewport to the correct output resolution, so you don't even have to worry about choosing a 4:3 ratio. This is faster and simpler, and while the interface may vary from what's shown in Figure 5.28, virtually all editors offer these controls.

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    DV 101. A Hands-On Guide for Business, Government & Educators
    DV 101: A Hands-On Guide for Business, Government and Educators
    ISBN: 0321348974
    EAN: 2147483647
    Year: 2005
    Pages: 110
    Authors: Jan Ozer

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