Hi Alejandro
Dédalo is builded to preserve data. Full deletion is avoided by design (too dangerous) and it's only available with accessing to the Database and only for Admins with tech knowledge. The addition an interface to do bulk deletions was debated for long time and for now the decision is; better no. (maybe we can discourse about it... )
So, if you want delete all images in resources (rsc170) you need to be able to enter in PostgreSQL and delete it with a command as:
In PostgreSQL:
1.- Delete the records:
DELETE FROM "matrix"
WHERE "section_tipo" = 'rsc170';
(maybe you should change the DELETE to SELECT to be sure that the command is correct before delete....)
2.- Delete the counter:
DELETE FROM "matrix_counter"
WHERE "tipo" = 'rsc170';
(maybe you should change the DELETE to SELECT to be sure that the command is correct before delete....)
3.- Delete the files in the server:
rm -R ../httpdocs/dedalo/media/image/*
With this 3 steps you will delete all image sections and all image files...
Be very careful doing it.
Note: if your DDBB does not has any good data, and you only has a test data, maybe is better to think do a fresh install.
Best.