I wanna make soft corp of the thumbnail so that use the other plugins to that image corp. There is plugin I use , "Regenerate Thumbnail", after regenerating then there still old files exist. I gonna looking the backend Media, but the thumbnail is the fileName-100x100.gif and the srcset is fileName-109x109.gif.

After found out the files in the command line, I try to delete the 2 files directly. Despite removing the image, the image would auto-generate when I access the Edit Image.However, my setting didn't define any 100 by 100 or 109 dimension that hardly traces the problem.

So far as my solution, with the Edit Image -> Scale Image to suit my size then upload the new image after saving the new image with scaled size. Save and upload apparently not a good solution for me even it works, I have to found out the efficient solution that would handle the lot images process.

There is my Setting-Media :