Add recycle() method

Author: yushulx

README.md

@@ -289,6 +289,7 @@ $ scandocument -c 1 -l <license-key>
     ```python
     normalized_image.save(<filename>)
     ```
+- `normalized_image.recycle()` # release the memory of the normalized image
 
 ## C/C++ API
 To customize Python API based on C/C++, please refer to the

docscanner/scripts.py

@@ -39,6 +39,7 @@ def process_file(filename, scanner):
 
     normalized_image.save(str(time.time()) + '.png')
     print('Image saved')
+    normalized_image.recycle()
 
 def process_video(scanner):
     scanner.addAsyncListener(callback)
@@ -74,8 +75,7 @@ def process_video(scanner):
                 cv2.destroyWindow(data[0])
                 data[1].save(str(time.time()) + '.png')
                 print('Image saved')
-                
-            g_normalized_images = []
+                data[1].recycle()
 
         if image is not None:
             scanner.detectMatAsync(image)
@@ -98,6 +98,10 @@ def process_video(scanner):
         cv2.putText(image, 'Press "ESC" to exit', (10, 90), cv2.FONT_HERSHEY_SIMPLEX, 0.8, (0, 0, 255), 2)
         cv2.imshow('Document Scanner', image)
 
+    for data in g_normalized_images:
+        data[1].recycle()
+
+
 def scandocument():
     """
     Command-line script for scanning documents from a given image or camera video stream.

examples/camera/test.py

@@ -51,9 +51,8 @@ def process_video(scanner):
                 cv2.destroyWindow(data[0])
                 data[1].save(str(time.time()) + '.png')
                 print('Image saved')
+                data[1].recycle()
 
-            g_normalized_images = []
-            
         if image is not None:
             scanner.detectMatAsync(image)
 
@@ -74,6 +73,9 @@ def process_video(scanner):
         cv2.putText(image, 'Press "s" to save image', (10, 60), cv2.FONT_HERSHEY_SIMPLEX, 0.8, (0, 0, 255), 2)
         cv2.putText(image, 'Press "ESC" to exit', (10, 90), cv2.FONT_HERSHEY_SIMPLEX, 0.8, (0, 0, 255), 2)
         cv2.imshow('Document Scanner', image)
+        
+    for data in g_normalized_images:
+        data[1].recycle()
 
 def scandocument():
     """

examples/file/test.py

@@ -32,6 +32,7 @@ def process_file(filename, scanner):
 
     normalized_image.save(str(time.time()) + '.png')
     print('Image saved')
+    normalized_image.recycle()
 
 def scandocument():
     """

src/document_scanner.h

@@ -444,6 +444,7 @@ static PyObject *normalizeFile(PyObject *obj, PyObject *args)
     quad.points[3].coordinate[1] = y4;
 
     NormalizedImageResult* normalizedResult = NULL;
+    
     int errorCode = DDN_NormalizeFile(self->handler, pFileName, "", &quad, &normalizedResult);
     if (errorCode != DM_OK)
         printf("%s\r\n", DC_GetErrorString(errorCode));

src/normalized_image.h

@@ -58,6 +58,19 @@ static PyObject *save(PyObject *obj, PyObject *args)
     return Py_BuildValue("i", -1);
 }
 
+static PyObject *recycle(PyObject *obj, PyObject *args)
+{
+    NormalizedImage *self = (NormalizedImage *)obj;
+
+    if (self->normalizedResult)
+    {
+        DDN_FreeNormalizedImageResult(&self->normalizedResult);
+        self->normalizedResult = NULL;
+    }
+
+    return Py_BuildValue("i", 0);
+}
+
 static PyMemberDef NormalizedImage_members[] = {
     {"bytearray", T_OBJECT_EX, offsetof(NormalizedImage, bytearray), 0, "bytearray"},
     {"length", T_OBJECT_EX, offsetof(NormalizedImage, length), 0, "length"},
@@ -70,6 +83,7 @@ static PyMemberDef NormalizedImage_members[] = {
 
 static PyMethodDef ni_instance_methods[] = {
     {"save", save, METH_VARARGS, NULL},
+    {"recycle", recycle, METH_VARARGS, NULL},
     {NULL, NULL, 0, NULL}
 };
 

test.py

@@ -35,6 +35,7 @@ def showNormalizedImage(name, normalized_image):
     print(x1, y1, x2, y2, x3, y3, x4, y4)
 
     normalized_image = scanner.normalizeFile("images/1.png", x1, y1, x2, y2, x3, y3, x4, y4)
+    normalized_image.recycle()
     # showNormalizedImage("Normalized Image", normalized_image)
     # cv2.drawContours(image, [np.int0([(x1, y1), (x2, y2), (x3, y3), (x4, y4)])], 0, (0, 255, 0), 2)
 
@@ -60,6 +61,7 @@ def showNormalizedImage(name, normalized_image):
 
 #     normalized_image = scanner.normalizeBuffer(image, x1, y1, x2, y2, x3, y3, x4, y4)
 #     showNormalizedImage("Normalized Image", normalized_image)
+#     normalized_image.recycle()
 #     cv2.drawContours(image, [np.int0([(x1, y1), (x2, y2), (x3, y3), (x4, y4)])], 0, (0, 255, 0), 2)
 
 # cv2.imshow('Document Image', image)
@@ -130,6 +132,7 @@ def showNormalizedImage(name, normalized_image):
 #             cv2.destroyWindow(data[0])
 #             data[1].save(str(time.time()) + '.png')
 #             print('Image saved')
+#             data[1].recycle()
 
 #         g_normalized_images = []