When I export as a .pdf, images end up with a weird halo effect that is very bad. Does anyone know how I can stop this happening? I've attached what the image looks like in the editor vs in the exported PDF.

The right image is a bitmap with transparency or is there any filter applied ?

Feel free to share the svg file for examination.

Hi thanks for your reply.

The right image is what it should look like, and how it appears in the editor. The left image is what happens to it after exporting as a .pdf.

The original image is a rasterised image in a .pdf exported from CairoMakie (Julia programming language). It looks fine in the original pdf file that CairoMakie creates. I then import that .pdf file into inkscape, make some minor changes to other parts of the figure (this is a small part of a larger figure), and re-export as a .pdf.

The image does have a transparent background. I have not applied any filters myself.

The effect goes away if I make the image very large in the editor, convert it to a bitmap (Alt + B) and then make it small again. This is quite tedious as I have a lot of images floating around in quite a large figure. I'm not really sure what's going wrong and why converting an image to a bitmap (only when it's large) and then making it small helps. I assume the halo effect is a fixed size, so percentage-wise it's smaller when it happens on a larger image. But it would be nice to avoid it altogether as it doesn't appear at all in the original exported .pdf from CairoMakie.