POST base64 image to web API using Swift 4 - swift

Question

I'm trying to make a call to the OCR.space API by uploading a base 64 image but I keep getting this response:
Not a valid base64 image. The accepted base64 image format is 'data:image/;base64,'
I've checked the image many times to make sure it's encoded properly in base 64 format. Am I setting up the URLRequest properly?
Here is the code:
func extractTextFromImage(_ image: CGImage) {
let bitmapRep = NSBitmapImageRep(cgImage: image)
let imageData = bitmapRep.representation(using: NSBitmapImageRep.FileType.jpeg, properties: [:])! as Data
let imageString = imageData.base64EncodedString(options: .endLineWithCarriageReturn)
let url = URL(string: "https://api.ocr.space/parse/image")!
let session = URLSession.shared
var request = URLRequest(url: url)
request.httpMethod = "POST"
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
request.addValue("application/json", forHTTPHeaderField: "Accept")
request.addValue("6ea787d56088957", forHTTPHeaderField: "apikey")
var parameters = ["base64image": [ "content_type": "image/jpeg", "base64": imageString]]
do {
let jsonData = try JSONSerialization.data(withJSONObject: parameters, options: [])
let theJSONText = String(data: jsonData, encoding: String.Encoding.utf8)
print("JSON string = \(theJSONText)")
request.httpBody = jsonData
} catch {
print(error.localizedDescription)
print("ERROR: Could not convert dictionary to JSON")
return
}
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
request.addValue("6ea787d56088957", forHTTPHeaderField: "apikey")
let task: URLSessionDataTask = session.dataTask(with: request, completionHandler: { (data: Data?, response: URLResponse?, error: Error?) -> Void in
if let response = response {
print("RESPONSE: ", response)
} else {
print("ERROR: No response")
}
if let error = error {
print("ERROR: ", error)
} else {
print("No error")
}
do {
let dictionary = try JSONSerialization.jsonObject(with: data!, options: []) as! [String: Any]
for (key, value) in dictionary {
print("Key: ", key)
print("Value: ", value)
}
if let parsedResults = dictionary["ParsedResults"] as? [[String: Any]] {
if let parsedResult = parsedResults.first {
if let parsedText = parsedResult["ParsedText"] as? String {
print("PARSED TEXT ", parsedText)
} else {
print("ERROR: Could not read parsedText")
}
} else {
print("ERROR: Could not read first element of parsedResult")
}
} else {
print("ERROR: Could not read parsedResult")
}
} catch let error {
print("ERROR: Could not serialize jSON Data: \(error.localizedDescription)")
}
})
task.resume()
}

Answer 1

After alot of reading and searching, this is the code that I got to work:
///
/// Extracts the text from the given image by placing a call to the OCR.space web api
///
func extractText(from image: CGImage) {
let bitmapRep = NSBitmapImageRep(cgImage: image)
let imageData = bitmapRep.representation(using: NSBitmapImageRep.FileType.png, properties: [:])! as Data
let url = URL(string: "https://api.ocr.space/parse/image")!
let session = URLSession.shared
var request = URLRequest(url: url)
request.httpMethod = "POST"
let boundary = "--------69-69-69-69-69"
request.setValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")
request.addValue("application/json", forHTTPHeaderField: "Accept")
request.addValue("6ea787d56088957", forHTTPHeaderField: "apikey")
request.httpBody = createBody(parameters: nil, filePathKey: "file", imageDataKey: imageData, boundary: boundary)
let task = session.synchronousDataTask(urlrequest: request)
let data = task.0
let error = task.2
if data == nil {
print("ERROR: No response from OCR.space api call")
return
}
if error != nil {
print("ERROR: ", error!)
return
}
do {
let dictionary = try JSONSerialization.jsonObject(with: data!, options: []) as! [String: Any]
if let parsedResults = dictionary["ParsedResults"] as? [[String: Any]] {
if let parsedResult = parsedResults.first {
if let text = parsedResult["ParsedText"] as? String {
parsedText = text
return
} else {
print("ERROR: Could not read parsedText")
return
}
} else {
print("ERROR: Could not read first element of parsedResult")
return
}
} else {
print("ERROR: Could not read parsedResult")
return
}
} catch let error {
print("ERROR: Could not serialize jSON Data into dictionary: \(error.localizedDescription)")
return
}
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
///
/// Creates a the body of the url request using the given parameters
///
private func createBody(parameters: [String: String]?, filePathKey: String?, imageDataKey: Data, boundary: String) -> Data {
var body = Data();
if parameters != nil {
for (key, value) in parameters! {
body.append("--\(boundary)\r\n".data(using: String.Encoding.utf8)!)
body.append("Content-Disposition: form-data; name=\"\(key)\"\r\n\r\n".data(using: String.Encoding.utf8)!)
body.append("\(value)\r\n".data(using: String.Encoding.utf8)!)
}
}
let filename = "image.jpg"
let mimetype = "image/jpg"
body.append("--\(boundary)\r\n".data(using: String.Encoding.utf8)!)
body.append("Content-Disposition: form-data; name=\"\(filePathKey!)\"; filename=\"\(filename)\"\r\n".data(using: String.Encoding.utf8)!)
body.append("Content-Type: \(mimetype)\r\n\r\n".data(using: String.Encoding.utf8)!)
body.append(imageDataKey)
body.append("\r\n".data(using: String.Encoding.utf8)!)
body.append("--\(boundary)--\r\n".data(using: String.Encoding.utf8)!)
return body
}