> For the complete documentation index, see [llms.txt](https://astra-image.gitbook.io/astra-image-6.0/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://astra-image.gitbook.io/astra-image-6.0/python-scripts/function-reference.md).

# Function Reference

**getPixel(x, y)**\
Gets the value of the pixel and the x,y coordinate and returns an RGB value as a tuple.

Example:

<mark style="color:orange;">p = ai.getPixel(100,100)</mark>

<mark style="color:orange;">print(p)</mark>

The result will display the RGB values of the pixel at 100, 100, with values between 0.0 and 1.0:

<mark style="color:orange;">(0.30588236451148987, 0.5372549295425415, 0.843137264251709)</mark>

**setPixel(x, y, r, g, b)**\
Sets the pixel at the x,y coordinate to the RGB value. The RGB values must be between 0.0 and 1.0. The setPixel function can be slow, so for processing a large image, it is recommended to use numpy where possible.

Example:

<mark style="color:orange;">ai.setPixel(100, 100, 1.0, 0.0, 0.0)</mark> \ <mark style="color:orange;">ai.updateImage()</mark>

This will set the pixel at 100,100 to pure red.

**updateImage()**\
When modifying the pixel values, use updateImage to see the changes.

**getWidth()**\
Returns the width of the image in pixels.

**getHeight()**\
Returns the height of the image in pixels.

**newImage(width, height)**\
Creates a new, empty image with the dimensions of width and height.

Example:

<mark style="color:orange;">ai.newImage(256,256)</mark>

<mark style="color:orange;">for y in range(0, 256):</mark>\
&#x20;  <mark style="color:orange;">for x in range(0, 256):</mark>\
&#x20;    <mark style="color:orange;">ai.setPixel(x, y, 1.0, 0, 0)</mark>

<mark style="color:orange;">ai.updateImage()</mark>

This will create a new 256 by 256 pixel image and set all the pixels to red.

**openImage(filename)**\
Opens a file from disk. At the moment, this function **does not support Unicode** characters. Please note that on Windows you cannot directly pass the path as a string.

Examples the successfully open an image:

<mark style="color:orange;">ai.openImage('c:/users/public/pictures/image.jpg')</mark> \ <mark style="color:orange;">ai.openImage(r'c:\users\public\pictures\image.jpg')</mark> <br>

Example that will **not** work on Windows (will result in a Python error):

<mark style="color:orange;">ai.openImage('c:\users\public\pictures\image.jpg')</mark>

Result:

<mark style="color:orange;">File "", line 3 ai.openImage('c:\users\public\pictures\image.jpg') ^ SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position 2-3: truncated \uXXXX escape</mark>

**getImageDataFloat()**\
Gets the image data from Astra Image for use in numpy.

Example:

<mark style="color:orange;">data = np.frombuffer(ai.getImageDataFloat(), dtype=np.float32)</mark>

The variable data is now a 1-dimensional numpy array that contains the image data.

If you want to have an array with the width, height, channels format, you can do this:

<mark style="color:orange;">data.shape = (ai.getWidth(), ai.getHeight(), 3)</mark>

setImageDataFloat()\
Updates the image data in Astra Image from a numpy array.

Example:

<mark style="color:orange;">ai.setImageDataFloat(data.tobytes(), ai.getWidth(), ai.getHeight())</mark>

In this case, the information in the variable 'data' will be loaded into Astra Image. The image data should be in 32-bit floating point with a range of 0.0 to 1.0.

**getROI()** \
Gets the current region of interest as a tuple. If no region is defined, the result will be -1.

The result format for a rectangular region is: (left, top, right, bottom). When the line tool is being used the format will be(x, y, x1, y1), where x,y are the starting coordinates and x1,y1 are the ending coordinates of the line.

Example:

<mark style="color:orange;">roi = ai.getROI()</mark>

<mark style="color:orange;">print(roi)</mark>

If there is a valid region or line, the result will look like:

<mark style="color:orange;">(962, 622, 1624, 1362)</mark>

If there is no region or line, the result will look like this:

<mark style="color:orange;">(-1, -1, -1, -1)</mark>

**getCurrentFilename()**\
Gets the fully qualified filename of the current image.

Example:

<mark style="color:orange;">fn = ai.getCurrentFilename()</mark>

<mark style="color:orange;">print(fn)</mark>

Result:

<mark style="color:orange;">c:\users\public\pictures\image.jpg</mark>