Don't use ALIGNSPACE. The ECW format is a georeferenced image. It has the projection built into the image itself and this means you don't need a World file to georeference the image. The image can be added to your drawing using an FDO connection and this connection, when used properly, will (a) scale, (b) rotate and (c) position the image accurately. If you don't use the projection built into the ECW, then you are treating the image as though you are working in Plain Vanilla AutoCAD. The ECW image format is a step up and your workflow (your skill set) should step up with it.
Use MAPCONNECT
Instead of ALIGNSPACE, use a data connection. Add the ecw as a Feature Data Objec (FDO) using MAPCONNECT from the AutoCAD Map3D Toolset.
Use MAPWSPACE
Use Map Task Pane from MAPWSPACE to 'reduce' the image. Right click the raster layer in the task pane and use 'Resample Raster' to decrease the north-south and the east-west extents of the raster.
ROTATE UCS
Instead of ALIGNSPACE command, rotate the viewport's UCS. Rotating a UCS in one VP doesn't affect modelspace. Modelspace will still remain in World Coordinate. The UCS in one VP doesn't affect the rotation of other VPs--other VPs will remain in World Coordinates--unless of course you rotate those VPs too.
HERE'S AN EXAMPLE:
An ECW is added as an FDO. The Data Connect Palette is on the right and Map Task Pane on the left. See Image-1.
Image-1
Zoom in on the image=>Right click the ECW layer in the Map Task Pane and select Resample Raster. See Image-2
In this example, a zoom-in is performed. Only a skinny narrow portion on the eastern edge of the ECW remains displayed 'on-screen.' The Resample will effectively limit the extents of the ECW. It's not cropping the ECW (even though it behaves like a cropped image) it's just resampling the ECW to the portion that's visible on-screen. The off-screen parts are hidden or not displayed. You can get as creative as you want when displaying and hiding parts of your ECW. When you resample like this exercise you decrease the amount of pixels to be displayed and depending on the size of your resample, your performance can improve significantly despite the latency typically associated with an ECW.
Image-2
Zoom-out and you'll see the result after Resampling the ECW. See Image-3.
Image-3
Go to Layout Tab. Next, activate your Viewport then follow steps 1 through 4. See Image-4
Image-4
With the viewport still activated, rotate the viewport's UCS. In this example, step 6 entails 2 clicks: (a) at 0,0 and (b) a point that's directly on the x-axis' positive side. The red x- and y-axes don't have to be drawn, they are imaginary and have only been added for demonstration purposes. You can select any angle of rotation. See Image-5. When rotating the UCS, make sure your VP is activated and unlocked.
Image-5
When you go back to modelspace, you'll see the rotation was only applied to your viewport. The rotation didn't affect the orientation of the ECW in modelspace.
Chicagolooper
