Image min. dim.:
Define the minimum image sizes when the user resize the image
Image max. dim.:
Define the maximum image sizes when the user resize the image
Keep aspect ratio:
The relationship between height and width of a picture is known as the aspect ratio.
If this checkbox is checked this relationship is preserved during the resize.
Image jpeg quality:
If the saved image is a Jpeg You can adjust the Jpeg image quality.
80 is a normal quality for Jpeg image.
Make 1° thumb:
If checked the extension create a first thumbnail for every operation in the image edit dialog window
Make 2° thumb:
If checked the extension create a second thumbnail for every operation in the image edit dialog window
The dimensions of the thumbnail
The thumbnails image are saved in the same folder with the original image and a suffix will be added to the end of the image name.
For example if You upload an image like myImage.jpg and the suffix will be "_small" the thumbnails will be myImage_small.jpg.
The position of the suffix, can be before the name or between name and extension