.. _`Overlay Images`:

.. _`syip.overlay`:

Overlay Images
~~~~~~~~~~~~~~

.. image:: image_overlay.svg
   :width: 48


Combines two images by layering the first (top port) image on top of the other (bottom port) image
, with choice for combining operator. Images must have the same number of channels

:Algorithms:


  - *additive*

    Adds the two images together where they overlap.

    **use alpha channel:**
      Use last channel of source images as alpha channel

    **alpha:**
      Alpha value used when no alpha channel is given


  - *divide*

    Divides bottom image by all other images.

    **use alpha channel:**
      Use last channel of source images as alpha channel

    **alpha:**
      Alpha value used when no alpha channel is given


  - *layer*

    Layers on image on top of the other, alpha channel (if any) determines transparency. Otherwise alpha value below

    **use alpha channel:**
      Use last channel of source images as alpha channel

    **alpha:**
      Alpha value used when no alpha channel is given


  - *max*

    Takes the maximum value of the images.

    **use alpha channel:**
      Use last channel of source images as alpha channel

    **alpha:**
      Alpha value used when no alpha channel is given


  - *min*

    Takes the minimum value of the images.

    **use alpha channel:**
      Use last channel of source images as alpha channel

    **alpha:**
      Alpha value used when no alpha channel is given


  - *multiplicative*

    Multiplies images where they overlap.

    **use alpha channel:**
      Use last channel of source images as alpha channel

    **alpha:**
      Alpha value used when no alpha channel is given


  - *subtract*

    Subtracts top image from bottom.

    **use alpha channel:**
      Use last channel of source images as alpha channel

    **alpha:**
      Alpha value used when no alpha channel is given



:Inputs:
    **images** : image

        Input images

:Outputs:
    **result** : image

        result after filtering

*Ports*:

    **Inputs**:

        :images: image

            Input images

    **Outputs**:

        :result: image

            result after filtering

*Configuration*:

    **algorithm**
        (no description)
    **use alpha channel**
        (no description)
    **alpha**
        (no description)

.. automodule:: node_layers

.. class:: OverlayImages