Copy image from Keynote into Preview: image quality downgraded

Hi,

lately I've been experiencing problems when trying to extract images from Keynote and Pages files. If I copy (Cmd+c) any image (.png, .jpg...) from there and paste it into a Preview "New from clipboard" file, the resolution will immediately reduce by half. I cross-checked this doing the following:

- Take screenshot or find an already existing .png or .jpg file.

- Copy the image into keynote. Copy it again FROM keynote.

- New Preview file from clipboard and now the image looks blurry. Look at resolution and it is X.

- Open original file in preview and the image is indeed NOT blurry. Look at resolution and it is 2X.

This doesn't seem to happen for .pdf files. Only png and jpg. Has anyone experienced this before? Any tips?

Thanks.