For the past couple of years Photomerge in PS3 and PS4 has been sufficient for 95 percent of my stitches which are generally simply 2x flat stitches from shifting a T/S lens. These are all building interiors and exteriors with plenty of common points and overlap. This is an important part of my workflow and I do a few of these a week for clients. Up till recently they merged flawlessly. All of a sudden Photomerge can't seem to align any images giving me the error message "some images could not be automatically aligned". This happens under all the different merge modes. This also happens from Bridge or from open files in PS. It literally cannot merge any set of images. This is with the camera always on a tripod and exposure and WB locked down. The only thing that has changed is I have been playing with memory usage and cache levels trying to improve performance, but even after returning them to the original settings Photomerge will not complete a merge. It matters not what merge mode you use or whether you are working from raw files or tiffs or from Bridge or open files. I am having to do every stitch in Autopano Pro which slows down my workflow considerably and frankly does not work as well on keeping the lines straight. Widows XP with a huge scatch disk dedicated just to PS. Any thoughts. A reinstall?
A few people never need to reset preferences. My computer, with Vista 64, runs PsCS4 very well. However, I need to reset preferences fairly often. I have no idea why. I keep a folder called "PsCS4 PREFS" on my desktop. In that folder I keep two files. One is a Word document that contains (C:\Users\owner\AppData\Roaming\Adobe\Adobe Photoshop CS4\Adobe Photoshop CS4 Settings). This is a link that I paste into Windows Explorer which takes me to where the preferences are located. I then place a ~ at the beginning of the file called (Adobe Photoshop X64 Prefs.psp). This is the preferences file and is not recognized by Photoshop after adding the ~. Of course, it could simply be deleted.
The other file in my desktop folder is a good copy of my preferences that I then control drop & drag into the folder where the old preferences are located. THIS IS ALL DONE WITH PHOTOSHOP CLOSED. This only takes a couple of minutes to do and saves having to reset each individual setting.
The following probably only applies to my computer. If I suspect bad preferences I go to the Diffuse Filter and try to apply it to a photo. If, in the preview, everything that should be whiter is black I know my prefs are bad. I then use the above steps to repair them.
"Reset Preferences" refers to returning many of Photoshop's settings to the defaults you started with when you first installed it.
After having done so, you'll want to check every setting and change it to what you prefer. Many of them are in the Edit - Preferences dialog, but there are also preferences that you may have set up in individual panels that will have been set back to default.
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