Thank you again for your return.
If I go on the product page having for ID 40, in the HTML code I have this
img src = "http://mydomain/img/p/en-default-large_default.jpg"
I think that normally, I should have this
img src = "http://mydomain/img/p/2/8/1/281-large_default.jpg"
However, in my ps_image table, image 281 is well associated with the product ID.
In the directory img / p / 2/8/1 the image 281 is well adapted in 281-cart_default, 281-home_default, 281-large_default, 281-medium_default, 281-small_default.