I am attaching a Dropbox link containing one of the SID files. This image should be roughly centered at lat. 47.7922 and long. -122.2008. Local scale should be for both X and Y. Local offset should be 0 for both X and Y. False northing should be 0 and false easting should be 1640416.6666732284.
There seem to be some mistakes in your report here. Suggested corrections:
Local scale should be 0.25 US survey feet for both X and Y. (Added missing value, from .sdw worldfile.)
Local offset should be
0 for both X and Y 1305000 for X and 282000 for Y. (Corrected from .sdw with translation.)
False northing should be 0 (correct) and false easting should be
1640416.6666732284 1640416.667 (corrected from EPSG definition).
The problem is that M9 does not seem to be using any of the metadata from the SID file or the world file...
Manifold 9 is picking up metadata--but it may be incorrect (more on that below).
First though, you might be misunderstanding the import/link workflow for images. I have said a couple of times that I think the UI sets some traps here. Have a look at this thread (for a different projection) for basic workflow and some warnings.
For your image, try this.
- Import 27891.sid from a folder where the .sid, .sdw and .sid.aux.xml are present.
- Open the image 27891_Image.
- Go to Contents > Component.
- Click the set of calipers at the bottom, hover over Repair Initial Coordinate System, and crucially don't choose a projection from your favourites (a natural instinct, but incorrect for image data). Instead choose Edit Coordinate System at the top.
- Now you see the EPSG tab selected, EPSG:2926 highlighted in the list, a string of coordinate system parameters in JSON below that (as you say, the figures here are in metres), and at the bottom, a list of Metrics.
It is the metrics that are crucial.
- Click on the XY (Metrics) button at bottom right, then choose Edit Metrics.
Manifold initially has the XY metrics as follows (in US Survey Feet):
Local scale X 0.8202083333333332
Local scale Y 0.8202083333333332
Local offset X 4281487.499999999
Local offset Y 925194.9999999999
So yes, Manifold has picked up metadata for the image. But the values don't seem to be right (AFAIK). We can come back to why that might be, but for now, try correcting the XY metrics to:
Local scale X 0.25
Local scale Y 0.25
Local offset X 1305000
Local offset Y 282000
After pressing OK of the Metrics dialog you'll see the new metrics summarised in the panel at the bottom.
How does that line up?