How to Convert RGB to RGBA Over White: Algorithm Explained

Convert RGB to RGBA Over White: Algorithm

Converting from RGB to RGBA, particularly when displayed over white, can be achieved using a specific algorithm. Here's how it works:

1. Identify the Lowest Component: Determine the minimum value among the three RGB components (red, green, blue).
2. Calculate Alpha: Convert the lowest component to an alpha value by subtracting it from 255 and dividing by 255. This value represents the transparency level.
3. Scale RGB: Subtract the lowest component from each RGB component and divide the result by the alpha value. This scales up the remaining RGB components proportionally.

Example:

Convert RGB(152, 177, 202) to RGBA:

• Lowest component: 152
• Alpha: (255 - 152) / 255 ~ 0.404

• Scaled RGB:

  • Red: (152 - 152) / 0.404 = 0
  • Green: (177 - 152) / 0.404 ~ 62
  • Blue: (202 - 152) / 0.404 ~ 123

Therefore, RGB(152, 177, 202) is converted to RGBA(0, 62, 123, 0.404).

By implementing this algorithm, you can convert RGB colors to RGBA colors that remain transparent when displayed on a white background, providing a harmonious visual experience.

The above is the detailed content of How to Convert RGB to RGBA Over White: Algorithm Explained. For more information, please follow other related articles on the PHP Chinese website!