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Three Shot Color Sampling

Another method of color sampling is to position a color changing filter element in front of the sensor, then sequentially capture a red, green, and blue image. The three sets of image data are then combined pixel by pixel to provide RGB sampled color at each pixel location (see Figure 3).

Figure 3 - 3-Shot Color Sampling

Figure 4 - 3-Shot Color, Pixel Level Resolution

Since each color is sampled at each pixel, the resolving element of the system is the pixel, making the stated resolution of the system equal to the resolution of the image sensor. This means that an image captured by a 2048 x 2048 sensor maintains its 2048 x 2048 resolution. Also note that the saved file size did not change, it just contains more measured data. The results are visibly noticeable (see Figure 4).
One drawback to this method is that if the image is changing with time, the sequential image capture will produce an image with red, green and blue ghosts of your subject as it moves across the scene. Another possible concern is image exposure and capture time. This method triples the time, so if it is an issue with a single shot, it will be more of an issue with the three shot method.

Pick The Technology That Best Fits Your Application

As with any situation, the appropriate solution depends on your needs. If you have moving samples or need high throughput, then single shot color mosaic cameras would be most appropriate. If your sample is fixed and you have additional time, then you may benefit from the additional resolution from three shot color cameras.

Figure 5 - Color Mosaic vs. 3-Shot Color, Side-by-side comparison, fixed sample