Sorry if this is a newbie question, but I can't seem to find it in the Poser manual. How can I accurately convert a .bum file back into a .bmp or a .jpg? I've tried just grayscaling the .bum, but I end up with something that looks more like it's been fed through an Emboss filter. I'm not doing this to try to break copyrights, it's just that I recently upgraded to Poser Pro Pack and I'd like to be able to use the smaller .jpg files. Unfortunately, not all of the models I've acquired came with anything but a .bum bumpmap. I don't want to violate anyone's copyright, so if this is against the rules I won't bother. Sorry for the trouble, and thanks in advance. -Katoran

To my knowledge its not possible.

That's what I hope to do but still can't find away, hope someone know the answer.

Attached Link: http://www.soft-rabbit.com/

The re-conversion from .bum to grayscale is highly non-trivial und subject to a certain loss in quality. I wrote a filter (which is part of the "SpeedBump" package) for GraphicConverter which will do this job with reasonably good quality. Unfortunately it is Mac only and I'm currently unable to provide a PC version.

now I think you can rename it to BMP and open it in photoshop change it to greyscale then save it as any format..I have done that for a few products that I have bought but reversed the procedure by changing the JPG bumps to BMP to use with ProPack.. Hope this helps. Dave

Yes, Dave71 is right, just rename the .bum to .bmp. The result is a greenish... thingy which you can turn to grayscale in Photoshop or similar.

Hi Katoran

Dave and Papu are correct, but as you point out, the result is not exactly the same as the original bumpmap as the image has been converted to generate a directional information from the relief data in the bumpmap.

Personally I wouldn't worry too much about conversion, the jpg encoding may save you some space, but not much when you compare it with the size of all the other poser type files, and jpg encoding is lossy, which means a loss of some quality when you store textures and bumpmaps.

In terms of memory usage when these maps are loaded, poser expands the entire image to original size anyway, so there is no gain from storing the images on disk as jpgs.

Bill

Well, "not exactly the same" is a mild expression... it gets completely spoilt when you try to simply rename .bum to anything else. If the .bum is nothing but a raw structure in order to add an uneven surface then you might get away with it, but if it is supposed to supply real details then better stay clear off this method. Look at this example: On the left there is the grayscale template (actually a black "mountain" on a "white" valley), in the middle there is Poser's .bum conversion, and on the right you'll see the grayscale version of the .bum. There is no more difference between the "mountain" and the "valley" because they have the same level of gray. If you want to go back from the middle picture to the left one, you'll need a very complicated filter.

Martin's example perfectly demonstrates what I meant by "not possible". Being able to convert the file into another format isn't the same thing as making it usable as a bump map by Poser. ;) BTW: If you have Paint Shop Pro you don't have to change the extension to bmp to open it. PSP seems to recognize the file data as being the same as .bmp even though .bum isn't in its list of supported formats.

Thank you for the confirmation. Aside from the disk-space savings, I wanted to be able to modify some of the bumpmaps for specific uses, such as adding a scar to a specific character. However, I suppose it's better practice to make my own from scratch in those cases, since I need to learn to use Painter better anyway. (Not to mention less likely to violate copyright laws.) Thanks again. - Katoran

Interesting. I tried it out of curiosity from reading this thread and Photoshop wouldn't open the file no matter what I called it.

scifiguy, I don't want to brag too much... but my "GreyBump" filter *does* convert it back, and I'm terribly proud about this little thing... :-) If you look at the pictures (A, B, C from left to right): A is a snippet of a real Poser bump template, B is the .bum conversion of A, and C is the result from GreyBump applied to B. If you compare A with C than you can see some minor loss (the contrast is weaker and it is slightly blurred), but it is seriously better than nothing.