Sending PDF for recognition
To extract a text from a scanned PDF, send a POST request to the https://api.aspose.cloud/v5.0/ocr/RecognizePdf
Aspose.OCR Cloud REST API endpoint. To authorize the request, pass the access token in Authorization header (Bearer authentication).
The PDF file and recognition parameters are provided in JSON format in the request body.
{
"image": "PDF as Base64 string",
"settings": {
"language": "English",
"makeSkewCorrect": true,
"rotate": 0,
"makeBinarization": false,
"makeContrastCorrection": true,
"makeUpsampling": false,
"makeSpellCheck": false,
"dsrMode": "Regions",
"dsrConfidence": "Default",
"resultType": "Text"
}
}
Providing an scanned PDF
The PDF file is provided in a value of image
property as a Base64 encoded string.
getconf ARG_MAX
command to check the maximum length of the command arguments (in bytes).
Recognition settings
Property | Type | Default value | Description |
---|---|---|---|
language |
string | English |
Specify a language for recognition. |
makeSkewCorrect |
boolean | true |
Automatically correct page tilt (deskew) before proceeding to recognition. Automatic deskew works for pages rotated 15 degrees or less. If the page is rotated by a larger degree or upside down, you must manually specify the rotation angle. |
rotate |
integer | 0 |
Rotate a page by the specified degree. Should be used when the page is rotated at a significant angle, such as landscape or upside down. |
makeBinarization |
boolean | false |
Automatically convert page content to black and white before proceeding to recognition. |
makeContrastCorrection |
boolean | true |
Automatically increase the contrast of images on a page before proceeding to recognition. |
makeUpsampling |
boolean | false |
Intellectually upscale page content to improve small font recognition and detection of dense lines. |
makeSpellCheck |
boolean | false |
Automatically replace commonly misspelled words in recognition results with the correct ones. The dictionary is based on the selected recognition language. |
dsrMode |
string | Regions |
Document structure analysis algorithm. |
dsrConfidence |
string | Default |
Threshold for filtering content blocks detected by the selected structure analysis algorithm. |
resultType |
string | Text |
Recognition result format. |
Return value
If successful, this method returns a string with a unique identifier (GUID) of the PDF recognition request in the queue.
Otherwise, it returns a HTTP status code corresponding to the error.
What’s next
Recognition will take a few seconds, depending on the size of the PDF document and the current Aspose.Cloud load. See the article Fetching PDF recognition result for information on how to get a recognition result from the server.