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Color Gradient
I used “Generated Media” to create an elliptical color gradient, going from light blue in the center to dark blue outward. I also put keyframes to make the elliptical area gradually increase in size.
The resulting effect looked OK on the computer screen, but it looked aweful on my external monitor (a 9″ RCA TV set). The “gradient” looked very coarse, with elliptical bands in various shades of blue. To fix it, I tried Gaussian Blur over the color gradient, but it didn’t help.
Then I encoded the video in MPEG-2 and burned it onto a DVD. I watched it on a regular set and it looked even worse.
Is a normal TV set limited in it ability to revolve a color gradient? Or is it something I did wrong?
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1 Reply
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“Is a normal TV set limited in it ability to revolve a color gradient? Or is it something I did wrong?”
No, what you are seeing are digital artifacts (your TV is analog), compounded by compression. Gradients are very difficult to do in digital – it’s the nature of the beast. As the color or intensity changes, the digital value “snaps” to the next level – like a staircase. Worse, when compressed, the software looks at nearby colors and levels and groups them into a bigger “step” as the same color and level. On your PC you were looking at the AVI which is compressed at 5:1, and your PC screen could resolve 4-million colors. When it compresses to MPEG, the color gamut is reduced, so everything that is almost the same color is changed to be the same color. Thus, color gradients become stairsteps. Similarly, everything close to the same intensity becomes one intensity, so level gradients become stepped as well. When you are dealing with both, then it will really look bad when compressed.
If you look at titles and menus in Hollywood DVD’s (they are MPEG also), I don’t think that you will find any gradient effects. If you do find one, I would like to see it.
Steve Mann
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