more fireflies when I save an image

Hello, I have a bit of a problem when I export my picture from image render with “save as” ( also with file output in the node editor ), I tried in TGA, PNG, TIFF … there is always the same issue . There are more fireflies in the exported picture than in the image editor . You can see that on the picture below … If anyone can explain why I will be very greatfull …



Best regards , Nico