too many files in thumbs

I have around 15,000 products and uploaded a single picture for each product. But few days later I see around 300,000 files in wwwroot/images/thumbs! What could be wrong here?

---Settings---
version    4.2
mediasettings.associatedproductpicturesize  320
mediasettings.autocompletesearchthumbpicturesize  77
mediasettings.avatarpicturesize  120
mediasettings.azurecachecontrolheader  
mediasettings.cartthumbpicturesize  80
mediasettings.categorythumbpicturesize  370
mediasettings.defaultimagequality  60
mediasettings.defaultpicturezoomenabled  TRUE
mediasettings.imagesquarepicturesize  32
mediasettings.importproductimagesusinghash  TRUE
mediasettings.manufacturerthumbpicturesize  350
mediasettings.maximumimagesize  1640
mediasettings.minicartthumbpicturesize  95
mediasettings.multiplethumbdirectories  FALSE
mediasettings.productdetailspicturesize  510
mediasettings.productthumbpicturesize  360
mediasettings.productthumbpicturesizeonproductdetailspage  105
mediasettings.useabsoluteimagepath  TRUE
mediasettings.vendorthumbpicturesize  450

Hello,

Is it possible to identify how many copies of an image has been created?

Best regards,
Atul

I would also recommend you the following:

1. Please go to admin area > configuration > settings > media settings.
2. Enable "Multiple thumb directories" setting

If you change any settings, then you can delete the files in folder /images/thumbs.  They will automatically get generated.