I know nothing about stitching frames together but am wondering about a couple of things.
Can one use some dedicated fiducials, perhaps stuck on the glass film mounting plate - tiny enough so they can be cloned out in Photoshop in the assembled image?
Could the use of such fiducials reduce the overlap required from frame to frame - say to less than 10% of frame length and width?
Nate Potter, Austin TX.
I've read an account where someone did exactly that, i.e. using fiducials, and it was effective. 10% overlap should be ok in that situation. The sticking point might be how well the software can blend the tiles tonally with so little overlap. Just for reference, my last series had 24.6 % overlap vertically and 20% horizontally.
Software that allows homographic positioning seems like a better way forward than using software that expects frames to be captured through rotation. Hopefully, PTgui Pro's multiple viewpoint feature is another way of saying 'homographic'.
“You often feel tired, not because you've done too much, but because you've done too little of what sparks a light in you.”
― Alexander Den Heijer, Nothing You Don't Already Know
I just played around a bit in Phototshop with the light house files. Photomerge, in the "reposition only" mode, did a good job of merging the bottom two rows individually, and then it merged them together. It didn't work on the other areas, but I manually brought them in a row at a time, and using difference mode it was quite easy to put the tiles in place. After that, I ran "auto blend layers", and the file looked good. There's no need for these files to be warped to fit together. Repositioning is fine.
“You often feel tired, not because you've done too much, but because you've done too little of what sparks a light in you.”
― Alexander Den Heijer, Nothing You Don't Already Know
That's exactly the approach I was planning as a first effort. I hope it's practical in use, because I can't even afford a hundred bucks for new stitching software.
But I may bring in my computer imaging professor buddy at this point, and see if he's willing to assign a project to one of his classes. If we could write an appropriate set of user needs and requirements, there might be a GNU solution that is possible. More later, if there's anything positive to report.
Rick "who just paid bills--ugly" Denney
Alignment without correction of any kind did not strike me as a possible solution, a lens with no distortion?? I'm not knocking it, far from it, this is very good news. Better than one could have hoped for.
I'll have to test the idea on a number of other negatives. Another option is to use ICE and then manually add and edit only the problem areas. There shouldn't be very many.
Was there any benefit to using multiple viewpoints in PTgui Pro?
“You often feel tired, not because you've done too much, but because you've done too little of what sparks a light in you.”
― Alexander Den Heijer, Nothing You Don't Already Know
Here's another option if you have Photoshop CS5. http://blogs.adobe.com/jnack/2010/05...photoshop.html Download and install Photomerge Interactive Layout plug-in. This will bring back the "interactive" option in the Photomerge dialogue. Basically, this is an option that lets you drag options into place. You can choose reposition only, and there's a snap-to feature, which works pretty well. I just did this, and I was able to get a very nice stitch. The downside is that it is slow to load with 25 images, as in go get a sandwich slow. It might be quicker to do a row at a time and then use the automatic reposition to merge the rows. I'll give that a try.
“You often feel tired, not because you've done too much, but because you've done too little of what sparks a light in you.”
― Alexander Den Heijer, Nothing You Don't Already Know
Have yet to try viewpoints in the pro version..
I have been in touch with a friend of mine who teaches computer science at a university, and who has assigned our problem to one of his students to see if there is a configuration of ImageJ that can work and maybe even make the problem easier. To facilitate that effort, and to correct a large deficiency in the needs and requirements I posted here, I'll attempt some needs and requirements for the stitching portion of this effort in this post. This is a quickie effort to do a bit of systems engineering, and may miss some critical point. But I think all such documentation activity helps keep us from getting distracted, particularly as we seek assistance from people who haven't been following along.
User Needs
The user will make photographs of the negative being scanned in a tiled arrangement. These photographs may be stored as 8-bit JPEG, 8 or 16-bit TIFF, and RGB or monochrome. The photographs will provide the overlap needed to support accurate stitching. The position of each tile will not be more precise than +/- 2 mm, however. The planarity and parallelism between the negative and the DSLR's sensor plane is covered by other requirements, which, if fulfilled, should ensure lateral and geometric distortion less than one pixel over the length or height of each tile.
The user will take the resulting tiled images, run them through a batch process to correct for systematic variation in illumination provided by the light source. This batch process may use a calibration photo made by the user with no negative in the stage, as a means of recording light-source variability. The tile images will be exposed so that the histogram falls entirely within the dynamic range of the camera, and all tiles will use identical exposures.
After this batch process to correct for systematic variation in illumination, the tiles will be assembled by the user in the stitching software. The user will drag and drop image tiles into an assembly. The user prefers to create a single assembly for all the tiles, rather than creating intermediate sub-assemblies. After the arrangement of the tiles has been assembled, the stitching software will perform the stitch. If the stitching algorithm is unable to find the correct stitch line, the user will use manual location methods to precisely locate that tile with respect to its neighbors by moving the misaligned tile or group of tiles. The movements may be large--some multiple of the tile size--or as little as one pixel. The user will need to look at various parts of the stitch area of that tile at 100% actual pixels, and be able to quickly refer to different portions of the stitch line, when performing this manual positioning. The user would prefer some aid in highlighting when the correct stitch has been found, such as some display that shows the one image subtracted from the other or some other mechanism.
The use may also name the tiled files in such a way that the position of each tile can be determined from the file name. The user will then identify a range of files to the stitching software interface to define the assembly arrangement. Using this approach, however, the user will still perform manual alignments in case an automatic stitch cannot be found.
Once the user is satisfied with the position of all the tiles, the user will direct the stitching software to complete the assembly.
The user will use a DSLR to scan up to 8x10 film. The user may use magnifications of 2:1, and may do so using as small as an APS-C sensor DSLR.
As a bonus, the user may incorporate the stitching process into a larger process that directs the movements of the negative stage, etc. Integration with these other process will be done by others. The integrator may use some form of scripting control to direct the stitching software as an embedded process, though the user will still provide manual positioning as necessary and confirm the final assembly.
Requirements
-The stitching system shall accommodate a range of input files
.... -The stitching system shall accommodate tile files in 8-bit JPEG.
.... -The stitching system shall accommodate tile files in 8-bit TIFF.
.... -The stitching system shall accommodate tile files in 16-bit TIFF.
.... -The stitching system shall accommodate RGB tile files.
.... -The stitching system shall accommodate monochrome tile files.
-The stitching system shall be able to assemble at least 240 image tiles.
-The stitching system shall provide a GUI for graphically arranging the tiles.
-The stitching system shall provide a batch assembly method using file names.
-The stitching system shall position each tile within the assembly by evaluating overlapping image information.
-The stitching system shall complete the entire assembly regardless of the inability to locate one or more individual tiles.
.... -The stitching software shall position individual tiles that cannot be located approximately, according to the arrangement plan.
-The stitching system shall identify tiles that could not be assembled algorithmically.
-The stitching system shall keep each tile separated until the assembly has been confirmed by the user.
-The stitching system shall allow manual positioning of any tile or group of tiles.
.... -The manual positioning shall accommodate dragging the tile anywhere within the entire assembly.
.... -The manual positioning shall accommodate precise single-pixel movements.
.... -The stitching system shall provide a display of overlapping tiles during manual movements
........ -The display shall provide up to six locations for viewing overlapping tiles during positioning
........ -The display shall highlight the overlapped area in such a way as to clearly identify when an accurate overlap has been obtained
........ -The display shall be zoomable from the entire assembly down to 100% (one file pixel equals one screen pixels)
-The stitching system shall allow the user to confirm that all tiles are correctly positioned.
-The stitching system shall create a TIFF file of the final assembly
.... -The final TIFF shall be 48-bit RGB for RGB tiles
.... -The final TIFF shall be 16-bit monochrome for monochrome tiles
Bonus:
-The stitching system shall provide script control.
.... -The script control shall define the assembly of tiles
.... -The script control shall provide manual positioning
.... -The script control shall allow the user to confirm the positioning of all tiles before final assembly
(Edit: The filtering of a few spaces by the forum software really does make clean formatting of lists like this far more difficult.)
Rick "respectfully submitted" Denney
ImageJ: patchwork
Detailed explanation of the purpose of patchwork_ program
When we want to examine an object (e.g. cell) with a microscope, we
prefer to zoom in in certain areas of this object to get better
resolution, but we also want to have the whole picture. So we create
a mosaic by capturing parts of the object and getting images that
overlap (we need the overlap to reconstruct the object again).
Reconstructing the whole image from some smaller ones is the purpose
of this program.
from this: http://rsbweb.nih.gov/ij/plugins/patchwork.html
HtH with the homework
Posting Permissions
Reply With Quote
Bookmarks