# How to extract the x,y coordinated otf the center of pixel 200, 300 of a Rasters.Raster object?
**URL:** https://discourse.julialang.org/t/how-to-extract-the-x-y-coordinated-otf-the-center-of-pixel-200-300-of-a-rasters-raster-object/131936
**Category:** Geo
**Created:** [August 29, 2025, 9:50am UTC](https://discourse.julialang.org/t/how-to-extract-the-x-y-coordinated-otf-the-center-of-pixel-200-300-of-a-rasters-raster-object/131936 "2025-08-29T09:50:38Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)
#### Post date: [August 29, 2025, 9:50am UTC](https://discourse.julialang.org/t/how-to-extract-the-x-y-coordinated-otf-the-center-of-pixel-200-300-of-a-rasters-raster-object/131936/1 "2025-08-29T09:50:38Z")
Provided I have a Rasters.Raster object `foo`, how can I extract the coordinated at the centre of a given pixel, in the raster coordinates system ?
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### Author:  [@Raf](https://discourse.julialang.org/u/Raf)
#### Post date: [August 29, 2025, 11:02am UTC](https://discourse.julialang.org/t/how-to-extract-the-x-y-coordinated-otf-the-center-of-pixel-200-300-of-a-rasters-raster-object/131936/2 "2025-08-29T11:02:16Z")
Getting the center isn’t that straightforward as e.g. GDAL gives values in the corners. So you need to shift them.
You could manually do this:
```julia
using Rasters.Lookups
x, y = lookup(maybeshiftlocus(Center(), rast), (X, Y))
centerpoint = x[size(rast, X) ÷ 2], x[size(rast, Y) ÷ 2]
```
Or use `DimPoints` from DimensionalData which is like a lazy array over all the points made from the lookup values (coordinates in a spatial context):
```julia
centerpoint = DimPoints(maybeshiftlocus(Center(), rast))[(size(rast) .÷ 2)...]
```
(maybe adding a `locus` keyword to `DimPoints` would make this even cleaner)
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### Author:  [@alex-s-gardner](https://discourse.julialang.org/u/alex-s-gardner)
#### Post date: [August 29, 2025, 5:14pm UTC](https://discourse.julialang.org/t/how-to-extract-the-x-y-coordinated-otf-the-center-of-pixel-200-300-of-a-rasters-raster-object/131936/3 "2025-08-29T17:14:33Z")
@Raf these solutions look very convoluted for what I would consider a common operation (i.e. requesting grid centroids). Is there an argument to be made for a gridcentroid function?
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### Author:  [@Raf](https://discourse.julialang.org/u/Raf)
#### Post date: [August 30, 2025, 1:25am UTC](https://discourse.julialang.org/t/how-to-extract-the-x-y-coordinated-otf-the-center-of-pixel-200-300-of-a-rasters-raster-object/131936/4 "2025-08-30T01:25:59Z")
Do other similar packages have a function like that?
Do you mean just a wrapper that gives you a `DimPoints` objects?
```julia
centroids(rast::Raster) = DimPoints(maybeshiftlocus(Center(), dims(rast, (X(), Y())))
```
Feel free to write/document/PR that if you think so
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### Author:  [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)
#### Post date: [August 30, 2025, 8:32am UTC](https://discourse.julialang.org/t/how-to-extract-the-x-y-coordinated-otf-the-center-of-pixel-200-300-of-a-rasters-raster-object/131936/5 "2025-08-30T08:32:13Z")
In general, as a “casual” gis user, I find very useful in this package the “raster as a matrix” concept, it facilitates a lot the raster treatment, but I find complicated to pass from the (xid,yid) space to the coordinates space and vice versa (see also [my other post](https://discourse.julialang.org/t/how-to-get-value-and-matrix-index-at-a-given-x-y-point/129692/9)). Perhaps an API that facilitates these passages would be useful…
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### Author:  [@joa-quim](https://discourse.julialang.org/u/joa-quim)
#### Post date: [August 30, 2025, 10:03am UTC](https://discourse.julialang.org/t/how-to-extract-the-x-y-coordinated-otf-the-center-of-pixel-200-300-of-a-rasters-raster-object/131936/6 "2025-08-30T10:03:42Z")
I think you are talking about the Matlab’s [axes2pix](https://www.mathworks.com/help/images/ref/axes2pix.html) and pix2axes pair. GMT has them as well, though I never needed them as a user. Only for code developing.