OCRTEXT([Your Image Column]) - the text from the value of your image column
The OCRTEXT function allows you to access the text that appears in an image. Currently, the OCRTEXT function has the following limitations:
It requires an internet connection
It can only be used as an initial value or app formula
It cannot be nested inside of another formula. If you need to further process the output of the OCRTEXT function, you can use OCRTEXT([Image]) in a hidden column and then use that hidden column in your formulas (see the example below).
See this sample app for an example of OCRTEXT in action: https://www.appsheet.com/samples/How-to-grab-the-text-from-an-image-using-OCR?appGuidString=e6b13b43-6967-4d61-ab72-530c0d00004b
To extract specific fields from an image, see this article: https://help.appsheet.com/en/articles/3121758-optical-character-recognition-ocr