message: doc(Image): Add note about indexing convention
  Closes
diff: title: Image
  ---
  -An `itk/Image` is the N-dimensional image data structure for *itk.js*. To visualize an `itk/Image` with *vtk.js*, use `convertItkToVtkImage` from [`vtk.js/Sources/Common/DataModel/ITKHelper`](https://kitware.github.io/vtk-js/api/Common_DataModel_ITKHelper.html). `itk/Image` is a JavaScript object with the following properties:
  +An `itk/Image` is the N-dimensional image data structure for *itk.js*. `itk/Image` is a JavaScript object with the following properties:
  **imageType**: The [ImageType](./ImageType.html) for this image.
  **name**: An optional name, a `String`, that describes this image.
  @@ -12,3 +12,11 @@ An `itk/Image` is the N-dimensional image data structure for *itk.js*. To visual
  **data**: A [TypedArray](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray) containing the pixel buffer data.
  For more information, see [the description](https://itk.org/ITKSoftwareGuide/html/Book1/ITKSoftwareGuide-Book1ch4.html#x38-490004.1) of an `itk::Image` in the ITK Software Guide.
  +
  +Note that the `origin`, `spacing`, `direction`, and `size` are indexed with an `x`, `y`, `z` convention ordering. This is the reverse indexing convention relative to other libraries such as [TensorFlow.js](https://www.tensorflow.org/js). To generate a TensorFlow tensor from an `itk/Image`, `image`:
  +
  +```
  +const tensor = tf.tensor(image.data, image.size.reverse())
  +```
  +
  +To visualize an `itk/Image` with [vtk.js](https://kitware.github.io/vtk-js) use `convertItkToVtkImage` from [`vtk.js/Sources/Common/DataModel/ITKHelper`](https://kitware.github.io/vtk-js/api/Common_DataModel_ITKHelper.html).
  