REST API - Send Images to PEKAT
- Kristyna Janku
Image processing through API works on the principle of sending the image via HTTP request and getting a response with the result (contains Context by default, but there are also other response types available). Only one image can be sent per request.
Enable Process
User must enable ‘Process’ on the left of the panel in Camera tab to be able to process the image sent through API.
Request
The sending address consists of IP address, port, type and optionally further query parameters. The request method must be of ‘POST’ type, and the content type of ‘application/octet-stream’ type.
Find a practical API demonstration in Python at GitHub Image Analyze API.
IP Address
If the project runs on a local computer, the address is 127.0.0.1. If a remote computer is accessed, then you need to use the IP address of the remote computer.
Port
This is selected when starting the project.
API Key
If the project is running with “Secure image analyze” option enabled, each request in the parameter query must contain the API key that is generated after you enable this option.
'http://127.0.0.1:8000/analyze_image?api_key=553d7790-827c-11ec-978b-6da1176c0b00'Data
You can add extra information to the request. This string will be added to the context (key is data). It is available only in the Code module (context variable).
'http://127.0.0.1:8000/analyze_image?data=SomeInfo'In Code module you can access this string using:
context['data']Types
analyze_raw_image
Used for sending the image as raw data. For example, the numpy array in Python is converted to binary format.
You need to send the image dimensions in query parameters width and height.
Example of a 1920x1024 image:
If you are sending Bayer RG 8 data, it is necessary to add an argument bayer.
Example of a Python code sending requests with raw images from camera:
analyze_image
Is used for sending an image in ‘jpg’ or ‘png’ formats.
Basic example
Example with API key
Example Python code which sends images from a folder to Pekat project with API key:
Response type
Query parameter ‘response_type’ determines what content will be sent in the response that is returned from PEKAT VISION after processing the request. The request url changes in the following way (example for annotated_image response type):
If there are multiple query parameters, connect with '&', e.g. with API key:
Context
context – a serialized context in JSON format. The contents are explained on the Context page. You can access the context json from response using:
Images
Further options return a PNG image in binary form in the response. It needs to be decoded afterwards to further work with it as an image.
Example of decoding and showing the image with PIL library:
Example of decoding and showing the image with OpenCV library:
image – processed image - output image that passed through the flow, but without any heatmaps or rectangles (e.g. if the image is scaled during the flow, it returns scaled image).
annotated_image – processed image with annotations - heatmaps over the image
heatmap - response contains only the heat maps over the image (without the image!)…….
For all those image response types, the serialized context is added to the headers with the header title 'ContextBase64utf'. To get it to json form, you can use this code: