feat: add DetectOrientationScript method

all_test.go

@@ -321,6 +321,16 @@ func TestClient_HTML(t *testing.T) {
 	})
 }
 
+func TestClient_DetectOrientationScript(t *testing.T) {
+	client := NewClient()
+	defer client.Close()
+	client.SetImage("./test/data/004-rotated-text.png")
+	deg, _, script_name, _, err := client.DetectOrientationScript()
+	Expect(t, err).ToBe(nil)
+	Expect(t, deg).ToBe(180)
+	Expect(t, script_name).ToBe("Latin")
+}
+
 func TestGetAvailableLangs(t *testing.T) {
 	t.Skip("TODO")
 	// langs, err := GetAvailableLanguages()

client.go

@@ -312,14 +312,42 @@
 	return nil
 }
 
+// Initialize tesseract::TessBaseAPI for OSD (Orientation and Script Detection)
+func (client *Client) initOsd() error {
+	var tessdataPrefix *C.char
+	if client.TessdataPrefix != "" {
+		tessdataPrefix = C.CString(client.TessdataPrefix)
+	}
+	defer C.free(unsafe.Pointer(tessdataPrefix))
+
+	res := C.Init(client.api, tessdataPrefix, C.CString("osd"), nil, nil)
+	if res != 0 {
+		return fmt.Errorf("failed to initialize TessBaseAPI with code %d", res)
+	}
+
+	if err := client.setVariablesToInitializedAPI(); err != nil {
+		return err
+	}
+
+	if client.pixImage == nil {
+		return fmt.Errorf("PixImage is not set, use SetImage or SetImageFromBytes before DetectOrientationScript")
+	}
+
+	C.SetPixImage(client.api, client.pixImage)
+
+	client.shouldInit = true
+
+	return nil
+}
+
 // This method flag the current instance to be initialized again on the next call to a function that
 // requires a gosseract API initialized: when user change the config file or the languages
 // the instance needs to init a new gosseract api
 func (client *Client) flagForInit() {
 	client.shouldInit = true
 }
 
-// This method sets all the sspecified variables to TessBaseAPI structure.
+// This method sets all the specified variables to TessBaseAPI structure.
 // Because `api->SetVariable` must be called after `api->Init()`,
 // gosseract.Client.SetVariable cannot call `api->SetVariable` directly.
 // See https://zdenop.github.io/tesseract-doc/classtesseract_1_1_tess_base_a_p_i.html#a2e09259c558c6d8e0f7e523cbaf5adf5
@@ -376,6 +404,25 @@
 	return
 }
 
+func (client *Client) DetectOrientationScript() (int, float32, string, float32, error) {
+	if err := client.initOsd(); err != nil {
+		return 0, 0, "", 0, err
+	}
+	var (
+		orient_deg  C.int
+		orient_conf C.float
+		script_name *C.char
+		script_conf C.float
+	)
+	defer C.free(unsafe.Pointer(script_name))
+	C.DetectOrientationScript(client.api, &orient_deg, &orient_conf, &script_name, &script_conf)
+	if script_name == nil {
+		return int(orient_deg), float32(orient_conf), "", float32(script_conf), fmt.Errorf("script name is null")
+	}
+
+	return int(orient_deg), float32(orient_conf), C.GoString(script_name), float32(script_conf), nil
+}
+
 // BoundingBox contains the position, confidence and UTF8 text of the recognized word
 type BoundingBox struct {
 	Box                                image.Rectangle

tessbridge.cpp

@@ -105,6 +105,11 @@ char* HOCRText(TessBaseAPI a) {
     return api->GetHOCRText(0);
 }
 
+void DetectOrientationScript(TessBaseAPI a, int* orient_deg, float* orient_conf, const char** script_name, float* script_conf) {
+    tesseract::TessBaseAPI* api = (tesseract::TessBaseAPI*)a;
+    api->DetectOrientationScript(orient_deg, orient_conf, script_name, script_conf);
+}
+
 bounding_boxes* GetBoundingBoxesVerbose(TessBaseAPI a) {
     using namespace tesseract;
     tesseract::TessBaseAPI* api = (tesseract::TessBaseAPI*)a;

tessbridge.h

@@ -31,6 +31,7 @@ void SetPageSegMode(TessBaseAPI, int);
 int GetPageSegMode(TessBaseAPI);
 char* UTF8Text(TessBaseAPI);
 char* HOCRText(TessBaseAPI);
+void DetectOrientationScript(TessBaseAPI, int*, float*, const char**, float*);
 const char* Version(TessBaseAPI);
 const char* GetDataPath();
 

test/runtimes/alpine.Dockerfile

@@ -7,7 +7,7 @@ RUN apk add \
   musl-dev \
   go \
   tesseract-ocr-dev
-RUN apk add tesseract-ocr-data-eng
+RUN apk add tesseract-ocr-data-osd tesseract-ocr-data-eng
 
 ENV GOPATH=/root/go