P: Printing to roll paper "auto roll length"

I would love to have this implemented.  Not hard for me to do manually, but seems like a task that LR could do for me.  It's all about ease of use.

Thanks, Johan. Very informative.

Jeremy

If QImage can do it, why not LR?

By @Jeremy Roussak

If Lightroom can stitch panoramas, why can't QImage? Lightroom can't do it because it wasn't implemented, that's all. Maybe Adobe felt it did not have priority, because calculating the size is no big deal. And so you filed a feature request to implement it. 

I wasn't suggesting that any guesswork was needed; and yes, of course it is usually easy to calculate. But why should I have to do arithmetic, with the possibility of error, when the computer which is about to send the data to the printer can do it for me? Why do I need a calculator to make a print? There's also the issue of more complex layouts, which are trickier to deal with and more prone to error. 

If QImage can do it, why not LR?

Isn't this pretty easy to calculate?  Using you Width/Height terminoligy the formula should be"

(Printer Width MMs / Number of Image Width Pixels) X Number of Image Height Pixels) = Printer Height MMs

Using your 610 mm width and an example 1830 X 6000 Pixel photo it should be:

(610/1830)X6000=2000 so roll length is 2000MM

NO guessing should be required.