Oops, I was using the wrong terminology, What I meant was "transparent sketches", as in the syntax below; sketches on # on/off # morphed sketches Anyway, to continue...
there is no way to make a jpeg transparent. Use png instead
Yes, on reflection I think I'd worked that out previously, and promptly forgotten!
Isn't much simpler to glue pictures in Elements?
I had not considered this. I was heading in the other direction, considering cutting up the existing scanned maps into smaller portions, (and erasing passages above or below the passage of interest), so that they could be handled more flexibly with therion. A bit like the concept of scraps for drawings, but using it for the 'sketch' images. For instance I could produce a map of only the middle levels in one part of the cave if I hand smaller 'sketch' image' pieces, rather than having to always see all of the passages above and below. Also distortions due to the (very poor) loop closure on the original maps being different to the therion loop closures means that one large 'sketch' image' will be handled poorly, but small 'sketch' images' may be an improvement. To explain the background... We have a 60km (and growing) cave system that has about four plan maps (the 'sketches') that cover the bulk of the cave, each covering 10 - 20km of passages that intertwine above each other. The paper maps are clearly a dead end, and therion offers a way to manage the data and drawings into the future. As a semi-permanent stop-gap measure we are trying to enter a skeleton framework of the survey data into therion, and overlay the 'sketch' images. Currently we have two 'sketches' loaded, such that with about 25km of survey data entered we can graphically represent 30-35km of cave. Five km has been drawn with therion, the rest as described above. The current therion pdf output is about 18 MB in size, obtained with about 1.5MB of 'sketches' as input. So, should I be persevering with transparent backgrounds and possibly smaller 'sketch' images, or stitch them all together and lose some functionality? Bruce