diff --git a/image_converter/image_converter.cpp b/image_converter/image_converter.cpp
index f0974c2..de6716b 100644
--- a/image_converter/image_converter.cpp
+++ b/image_converter/image_converter.cpp
@@ -8,7 +8,7 @@
 #include <algorithm>
 #include <stdlib.h>
 
-#define USE_OCV 1
+#define USE_OCV 0
 
 #if USE_OCV == 1
 #include <opencv2/opencv.hpp>
@@ -293,9 +293,9 @@ void visualize_track_bufs2(bit_array track_data0, bit_array track_data1, size_t
 void stitch_track_auto(disk_image *input_image, bool verbose) {
     disk_image_base_properties prop = input_image->get_property();
 
-    const size_t search_range_bfr = 512;         // search range before the 2nd index hole         
-    const size_t search_range_aft = 512;         // search range after the 2nd index hole
-    const size_t compare_byte_count = 256;      // bytes ((IBM(168): Gap4=80, SYNC=12, IAM=4, Gap1=50, Sync=12, IDAM=4, CHRN=4, CRC=2), (ISO(54): Gap1=32, SYNC=12, IDAM=4, CHRN=4, CRC=2))
+    const size_t search_range_bfr = 256;         // search range before the 2nd index hole         
+    const size_t search_range_aft = 256;         // search range after the 2nd index hole
+    const size_t compare_byte_count = 200;      // bytes ((IBM(168): Gap4=80, SYNC=12, IAM=4, Gap1=50, Sync=12, IDAM=4, CHRN=4, CRC=2), (ISO(54): Gap1=32, SYNC=12, IDAM=4, CHRN=4, CRC=2))
     const size_t bit_rate_2d = 500e3;
     const size_t samples_per_byte = (prop.m_sampling_rate/prop.m_data_bit_rate) * 8;
 
@@ -363,8 +363,6 @@ void stitch_track_auto(disk_image *input_image, bool verbose) {
                 }
             }
 
-            std::cout << dist_buf_ref.size() << ", " << dist_buf.size() << std::endl;
-
             if(verbose) {
                 std::cout << "Min error=" << min_error << ", Stitch pos=" << min_offset << ", Top of 2nd spin=" << pos_top_of_2nd_spin <<std::endl;
             }
@@ -383,6 +381,12 @@ void stitch_track_auto(disk_image *input_image, bool verbose) {
                 }
                 min_offset = pos_top_of_2nd_spin;
             }
+#else
+            if(min_error > dist_buf.size() * 6) {  // reference: when compare_byte_count==180, min_error is around 500~800 when stitching succeeded.
+                if(verbose) {
+                    std::cout << "*** Calculated error is very large." << std::endl;
+                }
+            }
 #endif
             tmp_track_data = bit_array{track_data};
             track_data.resize(min_offset);                       // perform track data trimming
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index f2c8af5..eeb5c14 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -1,55 +1,55 @@
-set(TEST_IMAGE_DIR ${CMAKE_SOURCE_DIR}/../fdc_bitstream_test)
-
-
-add_library(testutil util.cpp)
-target_include_directories(testutil PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
-target_link_libraries(testutil disk_image)
-
-
-
-add_executable(testRaw2d77 raw2d77.cpp)
-target_link_libraries(testRaw2d77 disk_image testutil)
-
-add_test(
-	NAME TEST_RAW_4MHz_TO_D77
-	COMMAND
-		testRaw2d77
-		"${CMAKE_SOURCE_DIR}/test_data/2019FM77AVDemo-4MHz.raw"
-		"${CMAKE_SOURCE_DIR}/test_data/2019FM77AVDemo.d77"
-		"${CMAKE_BINARY_DIR}"
-)
-add_test(
-	NAME TEST_RAW_8MHz_TO_D77
-	COMMAND
-		testRaw2d77
-		"${CMAKE_SOURCE_DIR}/test_data/2019FM77AVDemo-8MHz.raw"
-		"${CMAKE_SOURCE_DIR}/test_data/2019FM77AVDemo.d77"
-		"${CMAKE_BINARY_DIR}"
-)
-
-
-
-add_executable(testFormat format.cpp)
-target_link_libraries(testFormat disk_image testutil)
-add_test(
-	NAME TEST_FORMAT
-	COMMAND
-		testFormat
-)
-
-
-
-add_executable(testCompare compare.cpp)
-target_link_libraries(testCompare disk_image testutil)
-
-
-file(GLOB RAW_IMAGES "${TEST_IMAGE_DIR}/*.raw")
-
-foreach(RAW_IMAGE IN LISTS RAW_IMAGES)
- get_filename_component(RAW_IMAGE_BASE ${RAW_IMAGE} NAME_WE)
- message("FILE=${RAW_IMAGE_BASE}")
- add_test(
-  NAME "COMPARE_${RAW_IMAGE_BASE}"
-  COMMAND testCompare ${TEST_IMAGE_DIR}/${RAW_IMAGE_BASE}.d77 ${TEST_IMAGE_DIR}/${RAW_IMAGE_BASE}.raw ${TEST_IMAGE_DIR}/${RAW_IMAGE_BASE}.opt
- ) # Memo-to-myself:  Put D77 first.  RAW may have extra broken sector from overlap read.
-endforeach()
+set(TEST_IMAGE_DIR ${CMAKE_SOURCE_DIR}/../fdc_bitstream_test)
+
+
+add_library(testutil util.cpp)
+target_include_directories(testutil PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
+target_link_libraries(testutil disk_image)
+
+
+
+add_executable(testRaw2d77 raw2d77.cpp)
+target_link_libraries(testRaw2d77 disk_image testutil)
+
+add_test(
+	NAME TEST_RAW_4MHz_TO_D77
+	COMMAND
+		testRaw2d77
+		"${CMAKE_SOURCE_DIR}/test_data/2019FM77AVDemo-4MHz.raw"
+		"${CMAKE_SOURCE_DIR}/test_data/2019FM77AVDemo.d77"
+		"${CMAKE_BINARY_DIR}"
+)
+add_test(
+	NAME TEST_RAW_8MHz_TO_D77
+	COMMAND
+		testRaw2d77
+		"${CMAKE_SOURCE_DIR}/test_data/2019FM77AVDemo-8MHz.raw"
+		"${CMAKE_SOURCE_DIR}/test_data/2019FM77AVDemo.d77"
+		"${CMAKE_BINARY_DIR}"
+)
+
+
+
+add_executable(testFormat format.cpp)
+target_link_libraries(testFormat disk_image testutil)
+add_test(
+	NAME TEST_FORMAT
+	COMMAND
+		testFormat
+)
+
+
+
+add_executable(testCompare compare.cpp)
+target_link_libraries(testCompare disk_image testutil)
+
+
+file(GLOB RAW_IMAGES "${TEST_IMAGE_DIR}/*.raw")
+
+foreach(RAW_IMAGE IN LISTS RAW_IMAGES)
+ get_filename_component(RAW_IMAGE_BASE ${RAW_IMAGE} NAME_WE)
+ #message("FILE=${RAW_IMAGE_BASE}")
+ add_test(
+  NAME "COMPARE_${RAW_IMAGE_BASE}"
+  COMMAND testCompare ${TEST_IMAGE_DIR}/${RAW_IMAGE_BASE}.d77 ${TEST_IMAGE_DIR}/${RAW_IMAGE_BASE}.raw ${TEST_IMAGE_DIR}/${RAW_IMAGE_BASE}.opt
+ ) # Memo-to-myself:  Put D77 first.  RAW may have extra broken sector from overlap read.
+endforeach()