diff --git a/port/linux/package/pikascript/PikaCV.pyi b/port/linux/package/pikascript/PikaCV.pyi
index a1823f232..6c2fa362c 100644
--- a/port/linux/package/pikascript/PikaCV.pyi
+++ b/port/linux/package/pikascript/PikaCV.pyi
@@ -116,3 +116,13 @@ class Transforms(TinyObj):
     @staticmethod
     def rotateDown(image: Image):
         """Rotate the image """
+    def threshold(image:Image,thre:int,maxval:int,thresholdType:int):
+        """
+        0:THRESH_BINARY 
+        1:THRESH_BINARY_INV
+        2:THRESH_TRUNC
+        3:THRESH_TOZERO
+        4:THRESH_TOZERO_INV
+        """
+    def setROI(image:Image,x:int,y:int,w:int,h:int) :
+        """xywh"""
\ No newline at end of file
diff --git a/port/linux/package/pikascript/pikascript-lib/PikaCV/PikaCV_Transforms.c b/port/linux/package/pikascript/pikascript-lib/PikaCV/PikaCV_Transforms.c
index 693c9577f..cd8475a43 100644
--- a/port/linux/package/pikascript/pikascript-lib/PikaCV/PikaCV_Transforms.c
+++ b/port/linux/package/pikascript/pikascript-lib/PikaCV/PikaCV_Transforms.c
@@ -34,3 +34,88 @@ void PikaCV_Transforms_rotateDown(PikaObj* self, PikaObj* image) {
     img->size = size_new;
     arg_deinit(arg_data_new);
 }
+
+void PikaCV_Transforms_threshold(PikaObj *self, PikaObj* image, int maxval, int thre, int thresholdType){
+    PikaCV_Image* src = obj_getStruct(image, "image");
+    
+    if (NULL == src) {
+        pika_assert(0);
+        return;
+    }
+    if (src->format != PikaCV_ImageFormat_Type_GRAY) {
+        PikaCV_Converter_toGray(self,image);
+    }
+
+    uint8_t* src_data = _image_getData(image);
+    
+    int i;
+    if(thresholdType == 0 ){
+        for (i = 0; i < (src->size) ; i++) {
+            src_data[i] = src_data[i] > thre ? maxval : 0 ;
+        }
+    }
+    else if(thresholdType == 1 ){
+        for (i = 0; i < (src->size) ; i++) {
+            src_data[i] = src_data[i] > thre ? 0 : maxval ;
+        }
+    }
+    else if(thresholdType == 2 ){
+        for (i = 0; i < (src->size) ; i++) {
+            src_data[i] = src_data[i] > thre ? thre : src_data[i] ;
+        }
+    }
+    else if(thresholdType == 3 ){
+        for (i = 0; i < (src->size) ; i++) {
+            src_data[i] = src_data[i] > thre ? src_data[i] : 0 ;
+        }
+    }    
+    else if(thresholdType == 4 ){
+        for (i = 0; i < (src->size) ; i++) {
+            src_data[i] = src_data[i] > thre ? 0 : src_data[i] ;
+        }
+    }
+
+    obj_setBytes(image, "_data", src_data, src->size);
+}
+
+void PikaCV_Transforms_setROI(PikaObj *self, int h, PikaObj* image, int w, int x, int y){
+    PikaCV_Image* src = obj_getStruct(image, "image");
+    int width = src->width;
+    int height = src->height;
+
+    if (NULL == src) {
+        pika_assert(0);
+        return;
+    }
+    if (src->format != PikaCV_ImageFormat_Type_RGB888) {
+        PikaCV_Converter_toRGB888(self,image);
+    }
+    if( x <= 0 || y <= 0 || w <= 0 || h <= 0){
+        pika_assert(0);
+        return;
+    }
+    if( x + w > width || y + h > height ){
+        pika_assert(0);
+        return;
+    }
+
+    int size_new = h * w * 3;
+    Arg* arg_data_new = arg_setBytes(NULL, "", NULL, size_new);
+    uint8_t* data = _image_getData(image);
+    uint8_t* data_new = arg_getBytes(arg_data_new);
+
+    for(int i = 0 ; i < h ; i++){
+        for(int j = 0 ; j < w ; j++){
+            data_new[i * 3 * w + j * 3] = data[ (i + y-1) * width * 3 + (j + x - 1 ) * 3 ];
+            data_new[i * 3 * w + j * 3 + 1] = data[ (i + y-1) * width * 3 + ( j + x - 1 ) * 3 + 1];
+            data_new[i * 3 * w + j * 3 + 2] = data[ (i + y-1) * width * 3 + ( j + x - 1 ) * 3 + 2];
+        }
+    }
+    src->height=h;
+    src->width=w;
+    src->size = size_new;
+    
+    obj_setBytes(image, "_data", data_new, size_new);
+    arg_deinit(arg_data_new);
+
+}
\ No newline at end of file
diff --git a/port/linux/test/PikaCV-test.cpp b/port/linux/test/PikaCV-test.cpp
index 5d66f1e56..915afc50c 100644
--- a/port/linux/test/PikaCV-test.cpp
+++ b/port/linux/test/PikaCV-test.cpp
@@ -42,5 +42,35 @@ TEST(PikaCV, test3) {
     /* deinit */
     obj_deinit(pikaMain);
 
+    EXPECT_EQ(pikaMemNow(), 0);
+}
+
+TEST(PikaCV, test4) {
+    /* init */
+    pikaMemInfo.heapUsedMax = 0;
+    PikaObj* pikaMain = newRootObj("pikaMain", New_PikaMain);
+    /* run */
+    __platform_printf("BEGIN\r\n");
+    pikaVM_runSingleFile(pikaMain, "test/python/PikaCV/PikaCV_test4.py");
+    /* collect */
+    /* assert */
+    /* deinit */
+    obj_deinit(pikaMain);
+
+    EXPECT_EQ(pikaMemNow(), 0);
+}
+
+TEST(PikaCV, test5) {
+    /* init */
+    pikaMemInfo.heapUsedMax = 0;
+    PikaObj* pikaMain = newRootObj("pikaMain", New_PikaMain);
+    /* run */
+    __platform_printf("BEGIN\r\n");
+    pikaVM_runSingleFile(pikaMain, "test/python/PikaCV/PikaCV_test5.py");
+    /* collect */
+    /* assert */
+    /* deinit */
+    obj_deinit(pikaMain);
+
     EXPECT_EQ(pikaMemNow(), 0);
 }
\ No newline at end of file
diff --git a/port/linux/test/python/PikaCV/PikaCV_test4.py b/port/linux/test/python/PikaCV/PikaCV_test4.py
new file mode 100644
index 000000000..e77ce787c
--- /dev/null
+++ b/port/linux/test/python/PikaCV/PikaCV_test4.py
@@ -0,0 +1,9 @@
+import PikaCV as cv
+img = cv.Image()
+img.read("test/assets/test.jpg")
+
+cv.Converter.toGray(img)
+cv.Transforms.threshold(img,120,255,0)
+cv.Converter.toBMP(img)
+img.write("test/out/test.bmp")
+
diff --git a/port/linux/test/python/PikaCV/PikaCV_test5.py b/port/linux/test/python/PikaCV/PikaCV_test5.py
new file mode 100644
index 000000000..16dfd6763
--- /dev/null
+++ b/port/linux/test/python/PikaCV/PikaCV_test5.py
@@ -0,0 +1,7 @@
+import PikaCV as cv
+img = cv.Image()
+img.read("test/assets/test.jpg")
+cv.Converter.toRGB888(img)
+cv.Transforms.setROI(img,5,5,5,5)
+cv.Converter.toBMP(img)
+img.write("test/out/test1.bmp")