PNG pic size increase after resize

Wow, that’s a big increase in size. ?? I’ll ask the Photon developers what they think is the issue here.

So we had a look at the images. The original PNG is an indexed 1-bit b&w PNG. When it is rescaled by Photon, it needs to be antialiased, and therefore, greyscaled. Thus, it was switched to an 8-bit PNG, which explains the filesize increase.

so there is any way to stop that. i mean dont use photon on png images .

See https://www.ads-software.com/support/topic/disable-photon-for-gifs?replies=3#post-4104936 for an example of how to use the jetpack_photon_skip_image filter to skip types of images.