Fibonacci Ratio - Aurea Ratio

[Krikor]

Hello,
denzjos, rick2005, Sally and PixLab, All of your posts were very useful and helped me understand a little more about how to use GIMP for this purpose.

Here are some observations I made while playing around with this subject a little:

1- The script suggested by denzjos in post #2 definitely has a serious problem with the spiral it generates.
Namely, the spiral must form a quarter circle in each square that it circles. Which is clearly not the case with what is produced with this script.

   

Sally and PixLab remembered the option found in the rectangle select tool, but there is an important observation to understand in this case:
If your image is already in golden proportions (1:1.618 or 1.618:1) the GIMP Rectangle Select tool will work perfectly;
But if your image has any other aspect ratio, this tool does not correctly find the grid for that image's golden ratio.

   

The golden-rule.scm script, made available by rich2005, can generate the grid with the area ratio for your image, whether it is with or without the golden ratio aspect (1:1.618 or 1.618:1).

In the second image I posted, you can see the Ofnuts golden-spiral-0.0.py plugin in action.
Note that the generated path exceeds the height of the image (3239 x 4856).
I believe this occurs because the plugin expects the image to have the golden ratio, so considering the width to be 3239 px, the plugin considers the image height to be 5240 px.

PixLab, in your image, although the Rectangle select tool has the aspect ratio set at 1.618:1, you selected the Diagonal lines option.
I believe that the Golden sections option should be selected.

Thank you all!