The formula to convert a resolution to a scale is:
\[ \text{Scale} = 1 : (\text{R} \times \text{PPI}) \]
Where:
Scale refers to the ratio of the size of an image or model to the actual size of the object it represents. In the context of resolution, it is the ratio of the resolution in inches to the number of pixels per inch.
Resolution is a measure of the total size that one pixel represents. For example, a satellite image with a resolution of 1,000 inches per pixel means each pixel represents 1,000 inches on the ground. Scale, on the other hand, is the ratio of the image size to the actual size of the object.
Example 1:
Using the formula:
\[ \text{Scale} = 1 : (10 \times 100) = 1 : 1000 \]
Example 2:
Using the formula:
\[ \text{Scale} = 1 : (5 \times 200) = 1 : 1000 \]