What is the absolute relevance of bitmap editors?

[Xhris]

I want a discussion:

What can bitmap editing software (like Photoshop) do that vector software (in principle) can’t?

(This question should not be read as “what can Photoshop currently do that vector software can’t currently do”, or “please discuss the obvious distinction between bitmaps and vectors”, or “what would you change about Xara to stop it becoming a bitmap program”, and nor should this spiral into a Xara wish list or go off topic. Sorry for the strictness, but I want to say right from the off that I want it to be focussed and on topic and independent of Xara – Xara will not be mentioned again. I'm hoping for an earnest discussion.)

I’ve never really used bitmap editing software, and I’ve been flicking around on YouTube and the web etc. to see what typical uses people have for bitmap editing. I typically see photo-retouching, and changing the colour of objects such as hair etc. I see selection methods used, as well as warping/moulding of a selection, and the ‘healing’ of images. In principle, I can see all these functions being possible in a vector package, and all independently of resolution. I notice that the typical use of these editors is very object-oriented anyway through use of layers etc, but just being done at a fixed resolution.

Being more specific about the above uses I saw being used and how they could be applied (in principle) in a vector package: firstly, perhaps the most significant difference is the method of selection; a variety of tools/methods are employed to select regions of similar colour in bitmap editors. These range from magic wands, and other similar smart selection methods, to more sophisticated methods used when selecting objects with complex edges – such as fur. These methods could conceivably be applied to bitmaps and/or a collection of vector objects while in a vector package to select regions of similar colour.

Secondly, once regions are selected/masked; changing the colour properties (hue/sat/val etc) of the selection is done using a number of tools. Again all this could be done in a vector package – and to an extent, already is. Warping/moulding of selections using a variety of tools could be achieved in vector packages too; in the case of moulds: this is already capable to a certain extent. With tools like smudge etc, this again is also done to an extent in some vector packages (on vectors in this case – by pushing nodes around etc).

It recently occurred to me how ‘resolution independent’ operations could be performed on any bitmap and vector selections. A selection could be mapped to a high resolution matrix, and warping operations, for example, are simulated by manipulating colours on the vertices of the grid. This ultra-fine grid increases the effective resolution, allowing for such fancy features. In a vector package, any traditional “bitmap” tool could work in the same way; the selection is mapped to a high resolution matrix (with resolution determined by the internal maximum resolution of the product), and the transform operations are performed on that matrix (at the resolution being viewed at – i.e. the zoom factor/export resolution etc).

This would allow all effects to be produced in a vector manner; take ‘healing’ tools for example: the region to be healed is typically regenerated from an interpolation of the region surrounding the active region.

Objects would not even necessarily need to be selected to be operated on; imagine a collection of unselected objects in a vector package, and you dragged across them with a smudge/smear tool. It could apply a quasi-object over the drag region, and within the bounds of that quasi-object, apply all the effects desired given the information underneath using the method discussed above.

I like to think I see a future where only vector packages exist; I suspect that the reason why bitmap editors are still around, is that all these typical “bitmap” features are together already in one place within them. No one vector package has such tools that can be performed on both bitmap and/or vector groups as seen in these bitmap programs. In the long term, I just can’t see a future where there is a distinction between the two types of graphics package. I suspect (in an ideal world) future advanced vector products will incorporate all the tools (i.e. tool functionality) currently found bitmap editors, and become the dominant graphics-package-form.

But are there any (specifically) advanced tools/features/actions that are only possible to be performed in bitmap editors (i.e. to bitmaps only)? I can’t think of any given the method discussed above.