I have a scan of an old anatomic atlas; it's grayscale and not really bright. I suppose it's a copy of an engraving. My question is: is it possible to remove this background relatively easy? Or magnet lasso will be the only option?
Seems pretty straightforward with Photoshop CS6. I used the dropper tool to select the general background and did cleanup with the quick selection tool.
If the selection of the background ends up breaking due to the "grid pattern", you can work around it, like I did, by duplicating the later and applying a blur filter to smooth it out, then applying the magic wand selection. Switch back to the other later and fine tune with the quick selection tool.
All told, it took about 5-10 minutes to do the selection and rough cleanup. Can probably do a better job if you spend more time and then apply some filters to improve the contrast of the image.
Some tweaks to bring out the details of the original.