1

Arc Desktop 10.5.1

Background

I am converting an Arc Grid raster to a tif using the Raster To Other Format (multiple) tool.

In the tool's Environments... settings, I am snapping the output tif to a different tif raster.

All rasters involved have identical cell sizes (three feet), and all have the same horizontal and vertical CRS/projections.

My question:

The Environments... help implies that only an x/y shift occurs with raster snapping, without any sort of transformation (such as in a reprojection).

However, the Environments... help also states, within the Raster Storage section:

“Resampling is the process of interpolating the pixel values while transforming your raster dataset. This is used when the input and output do not line up exactly, when the pixel size changes, when the data is shifted, or a combination of these.” My emphasis.

My understanding has long been that a snap by itself would not invoke a transform (and thus resampling). But after a closer look at the above help (IMHO ambiguous) I'm not so sure! I need to know if it does so that I can then decide what resampling technique I want to use, so I'm asking for assistance: does a raster snap involve transforming, and thus resampling?

  • I think you want to use Shift, which just tweaks the metadata. – Vince May 10 '18 at 23:05
  • Thanks @Vince - Interesting! The Shift tool's help specifically states that it "...does not perform any resampling or warping." Great! But how does one determine what X and Y shift values to enter in the tool so that it aligns with a snap raster? Surely not a screen measurement!!! I tried using both blank and zero shift values along with my snap raster as tool inputs, figuring that would shift to the snap raster but no joy. And while we're at it, the idea of including both shift values AND a snap raster seem at odds with each other. Sigh, so close, yet so far... – Stu Smith May 11 '18 at 3:15
  • But I digress from the OP. I really would like to know if an Environments raster snap involves transforming, and thus resampling! – Stu Smith May 11 '18 at 3:17
  • I always described the rasters and calculated a delta, in AML back when, but Python now. I suspect the answer to the question is "It depends" but I'm unlikely to use that environment myself. – Vince May 11 '18 at 3:43

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.