Subtract Gaussian blur for normal black & white conversion as well

cbits/simplecv.c

@@ -285,7 +285,7 @@ unsigned char const * const single_to_multichannel(
   *
   * @param width Width of the image.
   * @param height Height of the image.
-  * @param use_double_threshold Use double thresholding.
+  * @param use_double_threshold Whether to use double thresholding.
   * @param data Pointer to the pixel data.
   * @return Pointer to the monochrome image data.
   */
@@ -492,9 +492,10 @@ unsigned char const * const apply_gaussian_blur(
   * @param data Pointer to the pixel data.
   * @return Pointer to the blurred image data.
   */
-unsigned char const * const bw_smooth_smart(
+unsigned char const * const bw_smart(
   unsigned int width,
   unsigned int height,
+  bool use_double_threshold,
   unsigned char const * const data
 ) {
   unsigned char const * const grayscale_data = grayscale(width, height, data);
@@ -534,7 +535,7 @@ unsigned char const * const bw_smooth_smart(
   free((void *)blurred_data);
 
   unsigned char const * const final_data = otsu_threshold_rgba(
-    width, height, true, high_freq_data
+    width, height, use_double_threshold, high_freq_data
   );
 
   free(high_freq_data);

cbits/simplecv.h

@@ -34,8 +34,9 @@ unsigned char const * const otsu_threshold_rgba(
   unsigned char const * const data
 );
 
-unsigned char const * const bw_smooth_smart(
+unsigned char const * const bw_smart(
   unsigned int width,
   unsigned int height,
+  bool use_double_threshold,
   unsigned char const * const data
 );

source/Lib.hs

@@ -929,13 +929,13 @@ correctAndWrite transformBackend inPath outPath ((bl, _), (tl, _), (tr, _), (br,
                 savePngImage outPath (ImageRGBA8 grayImg)
               --
               BlackWhiteExport -> do
-                bwImgPtr <- SCV.otsu_threshold_rgba width height False resutlImg
+                bwImgPtr <- SCV.bwSmart width height False resutlImg
                 bwImgForeignPtr <- newForeignPtr_ (castPtr bwImgPtr)
                 let bwImg = imageFromUnsafePtr width height bwImgForeignPtr
                 savePngImage outPath (ImageRGBA8 bwImg)
               --
               BlackWhiteSmoothExport -> do
-                bwImgPtr <- SCV.bwSmoothSmart width height resutlImg
+                bwImgPtr <- SCV.bwSmart width height True resutlImg
                 bwImgForeignPtr <- newForeignPtr_ (castPtr bwImgPtr)
                 let bwImg = imageFromUnsafePtr width height bwImgForeignPtr
                 savePngImage outPath (ImageRGBA8 bwImg)

source/SimpleCV.chs

@@ -141,9 +141,10 @@ instance Storable Matrix3x3 where
   } -> `Ptr CUChar' castPtr -- ^ Transformed image data
 #}
 
-{#fun bw_smooth_smart as ^
+{#fun bw_smart as ^
   {               `Int'        -- ^ width
   ,               `Int'        -- ^ height
+  ,               `Bool'       -- ^ whether to use double thresholding
   , identity      `Ptr CUChar' -- ^ Original image data
   } -> `Ptr CUChar' castPtr    -- ^ Anti-aliased black and white image data
 #}