Update applyColorMap document

modules/imgproc/include/opencv2/imgproc.hpp

@@ -4470,7 +4470,7 @@ An example using applyColorMap function
 
 /** @brief Applies a GNU Octave/MATLAB equivalent colormap on a given image.
 
-@param src The source image, grayscale or colored of type CV_8UC1 or CV_8UC3.
+@param src The source image, grayscale or colored of type CV_8UC1 or CV_8UC3. If CV_8UC3, then the CV_8UC1 image is generated internally using cv::COLOR_BGR2GRAY.
 @param dst The result is the colormapped source image. Note: Mat::create is called on dst.
 @param colormap The colormap to apply, see #ColormapTypes
 */
@@ -4478,8 +4478,8 @@ CV_EXPORTS_W void applyColorMap(InputArray src, OutputArray dst, int colormap);
 
 /** @brief Applies a user colormap on a given image.
 
-@param src The source image, grayscale or colored of type CV_8UC1 or CV_8UC3.
-@param dst The result is the colormapped source image. Note: Mat::create is called on dst.
+@param src The source image, grayscale or colored of type CV_8UC1 or CV_8UC3. If CV_8UC3, then the CV_8UC1 image is generated internally using cv::COLOR_BGR2GRAY.
+@param dst The result is the colormapped source image of the same number of channels as userColor. Note: Mat::create is called on dst.
 @param userColor The colormap to apply of type CV_8UC1 or CV_8UC3 and size 256
 */
 CV_EXPORTS_W void applyColorMap(InputArray src, OutputArray dst, InputArray userColor);