spelling fixes

modules/gapi/include/opencv2/gapi/core.hpp

@@ -1255,7 +1255,7 @@ GAPI_EXPORTS std::tuple<GMat, GMat> integral(const GMat& src, int sdepth = -1, i
 /** @brief Applies a fixed-level threshold to each matrix element.
 
 The function applies fixed-level thresholding to a single- or multiple-channel matrix.
-The function is typically used to get a bi-level (binary) image out of a grayscale image ( cmp funtions could be also used for
+The function is typically used to get a bi-level (binary) image out of a grayscale image ( cmp functions could be also used for
 this purpose) or for removing a noise, that is, filtering out pixels with too small or too large
 values. There are several depths of thresholding supported by the function. They are determined by
 depth parameter.

modules/gapi/include/opencv2/gapi/gcomputation.hpp

@@ -123,7 +123,7 @@ public:
      *
      * This may be useful since all temporary objects (cv::GMats) and
      * namespaces can be localized to scope of lambda, without
-     * contaminating the parent scope with probably unecessary objects
+     * contaminating the parent scope with probably unnecessary objects
      * and information.
      *
      * @param gen generator function which returns a cv::GComputation,

modules/gapi/include/opencv2/gapi/gkernel.hpp

@@ -376,7 +376,7 @@ namespace gapi {
     public:
         /**
          * @brief Returns total number of kernels in the package
-         * (accross all backends included)
+         * (across all backends included)
          *
          * @return a number of kernels in the package
          */