1. The problem is to understand the pixel brightness equation for grayscale images. 2. The formula given is: $$I(x,y) = \frac{R(x,y) + G(x,y) + B(x,y)}{3}$$ where $I(x,y)$ is the intensity (brightness) at pixel coordinates $(x,y)$, and $R(x,y)$, $G(x,y)$, $B(x,y)$ are the red, green, and blue color channel values at that pixel. 3. This formula calculates the average of the three color channels to convert a color pixel to grayscale. 4. Important rule: Each color channel value typically ranges from 0 to 255. Averaging them gives a single brightness value also in this range. 5. Example: If $R(10,20) = 100$, $G(10,20) = 150$, and $B(10,20) = 200$, then $$I(10,20) = \frac{100 + 150 + 200}{3} = \frac{450}{3} = 150$$ 6. This means the pixel at $(10,20)$ has a grayscale brightness of 150. 7. This method is simple and effective for converting color images to grayscale by averaging color intensities. Final answer: The pixel brightness equation for grayscale is $$I(x,y) = \frac{R(x,y) + G(x,y) + B(x,y)}{3}$$.