OCR Recognize Screen Region

OCR Recognize Screen Region

Type: ocr-recognize-region  ·  Package: OCR Activities v1.2.5  ·  Output: string

Captures a rectangular area of the screen and recognizes the text it contains. Useful to read data from an application that does not expose its text in an accessible way (an image viewer, a custom control, drawn content) when Desktop selectors can’t reach it.

How it works

Captures the region defined by x, y (top-left corner) and width, height (size), in screen pixels, and runs it through OCR. It requires an interactive desktop session: it captures what is visible at that moment, so the window must be in front with no other windows over it.

• Coordinates are counted from the top-left corner of the primary screen; with several monitors, screens to the left of or above the primary one have negative coordinates.
• This activity has no preprocessing. If the capture comes out with errors, save an image with Win Screenshot and read it with OCR Recognize File and preprocess = "auto".

Required parameters

Parameter	Type	Default	Description
x	int	—	Left coordinate of the area (px).
y	int	—	Top coordinate of the area (px).
width	int	—	Width of the area (px). Must be greater than zero.
height	int	—	Height of the area (px). Must be greater than zero.

Optional parameters

Parameter	Type	Default	Description
language	string	"eng"	Text language: Tesseract code (eng, spa, eng+spa) or regional tag (es-CO, en-US). See language.

Output

Returns a string with the text recognized in that region. If there is no readable text, it returns an empty string or one with only line breaks.

Example

OCR Recognize Screen Region   x = 100   y = 250   width = 400   height = 60   language = "spa"   → output: balance
Set Variable   name = balanceNumber   value = regexFind(balance, "[\d.,]+")

Fixed coordinates = fragile

Reading by screen coordinates depends on the resolution and on the window always being in the same place. Whenever the control is accessible, prefer Win Get Text (Desktop), which is much more robust. Use screen OCR only when there is no alternative.

Common errors

Message	Cause and fix
'width' and 'height' must be greater than zero.	The area size is 0 or negative.
'x' is required. (same for y, width, height)	One of the coordinates is missing.
Tesseract language '…' not found at '…'. Available: [eng, spa].	The language code is not installed.
Screen capture error	There is no interactive desktop (locked session or no user signed in). Run the robot in a session with an active desktop.

Related activities

• OCR Screenshot — read the whole screen.
• OCR Find Text — find the position of a text on screen.
• Win Get Text — robust alternative via UIA.