.. _`Overlay Images List`:

.. _`syip.overlay_list`:

Overlay Images List
~~~~~~~~~~~~~~~~~~~

.. 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, one at a time.

    **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


  - *median*

    Takes the median 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



*Input ports*:
    **images** : [image]

        Input images

*Output ports*:
    **result** : image

        result after filtering



*Configuration*:
    **Algorithm** (algorithm)
        (no description)
    **use alpha channel** (use alpha channel)
        (no description)
    **alpha** (alpha)
        (no description)

.. automodule:: node_layers

.. class:: OverlayImagesList