.. _PixelValue: 

PixelValue
==========





Get the value of a pixel.

Description
-----------

This application gives the value of a selected pixel. There are three ways to designate a pixel, with its index, its physical coordinate (in the physical space attached to the image), and with geographical coordinate system. Coordinates will be interpreted differently depending on which mode is chosen.



Parameters
----------

.. contents:: :local:

.. |br| raw:: html

   <br />

.. |em| raw:: html

   &emsp;

**Input Image** :code:`-in image` *Mandatory* |br|
Input image

**X coordinate** :code:`-coordx float` *Mandatory* |br|
This will be the X coordinate interpreted depending on the chosen mode

**Y coordinate** :code:`-coordy float` *Mandatory* |br|
This will be the Y coordinate interpreted depending on the chosen mode

**Coordinate system used to designate the pixel** :code:`-mode [index|physical|epsg]` *Default value: index* |br|
Different modes can be selected, default mode is Index.

* **Index** |br| This mode uses the given coordinates as index to locate the pixel.

* **Image physical space** |br| This mode interprets the given coordinates in the image physical space.

* **EPSG coordinates** |br| This mode interprets the given coordinates in the specified geographical coordinate system by the EPSG code.



EPSG coordinates options
^^^^^^^^^^^^^^^^^^^^^^^^

**EPSG code** :code:`-mode.epsg.code int` |br|
This code is used to define a geographical coordinate system. If no system is specified, WGS84 (EPSG: 4326) is used by default.



------------

**Channels** :code:`-cl string1 string2...` |br|
Displayed channels

**Pixel Value** :code:`-value string` *Mandatory* |br|
Pixel radiometric value



Examples
--------

From the command-line:

.. code-block:: bash

    otbcli_PixelValue -in QB_Toulouse_Ortho_XS.tif -coordx 50 -coordy 100 -cl Channel1


From Python:

.. code-block:: python

	import otbApplication

	app = otbApplication.Registry.CreateApplication("PixelValue")

	app.SetParameterString("in", "QB_Toulouse_Ortho_XS.tif")
	app.SetParameterFloat("coordx", 50)
	app.SetParameterFloat("coordy", 100)
	app.SetParameterStringList("cl", ['Channel1'])

	app.ExecuteAndWriteOutput()