diff options
Diffstat (limited to 'ml/dlib/dlib/image_transforms/thresholding_abstract.h')
| -rw-r--r-- | ml/dlib/dlib/image_transforms/thresholding_abstract.h | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/ml/dlib/dlib/image_transforms/thresholding_abstract.h b/ml/dlib/dlib/image_transforms/thresholding_abstract.h new file mode 100644 index 000000000..e7c1e8826 --- /dev/null +++ b/ml/dlib/dlib/image_transforms/thresholding_abstract.h @@ -0,0 +1,139 @@ +// Copyright (C) 2006 Davis E. King (davis@dlib.net) +// License: Boost Software License See LICENSE.txt for the full license. +#undef DLIB_THRESHOLDINg_ABSTRACT_ +#ifdef DLIB_THRESHOLDINg_ABSTRACT_ + +#include "../pixel.h" + +namespace dlib +{ + +// ---------------------------------------------------------------------------------------- + + const unsigned char on_pixel = 255; + const unsigned char off_pixel = 0; + +// ---------------------------------------------------------------------------------------- + + template < + typename in_image_type, + typename out_image_type + > + void threshold_image ( + const in_image_type& in_img, + out_image_type& out_img, + typename pixel_traits<typename image_traits<in_image_type>::pixel_type>::basic_pixel_type thresh + ); + /*! + requires + - in_image_type == is an implementation of array2d/array2d_kernel_abstract.h + - out_image_type == is an implementation of array2d/array2d_kernel_abstract.h + - pixel_traits<typename image_traits<out_image_type>::pixel_type>::grayscale == true + - pixel_traits<typename image_traits<in_image_type>::pixel_type>::has_alpha == false + - pixel_traits<typename image_traits<out_image_type>::pixel_type>::has_alpha == false + ensures + - #out_img == the thresholded version of in_img (in_img is converted to a grayscale + intensity image if it is color). Pixels in in_img with grayscale values >= thresh + have an output value of on_pixel and all others have a value of off_pixel. + - #out_img.nc() == in_img.nc() + - #out_img.nr() == in_img.nr() + !*/ + + template < + typename image_type + > + void threshold_image ( + image_type& img, + typename pixel_traits<typename image_traits<image_type>::pixel_type>::basic_pixel_type thresh + ); + /*! + requires + - it is valid to call threshold_image(img,img,thresh); + ensures + - calls threshold_image(img,img,thresh); + !*/ + +// ---------------------------------------------------------------------------------------- + + template < + typename in_image_type, + typename out_image_type + > + void auto_threshold_image ( + const in_image_type& in_img, + out_image_type& out_img + ); + /*! + requires + - in_image_type == is an implementation of array2d/array2d_kernel_abstract.h + - out_image_type == is an implementation of array2d/array2d_kernel_abstract.h + - pixel_traits<typename image_traits<in_image_type>::pixel_type>::max() <= 65535 + - pixel_traits<typename image_traits<in_image_type>::pixel_type>::has_alpha == false + - pixel_traits<typename image_traits<in_image_type>::pixel_type>::is_unsigned == true + - pixel_traits<typename image_traits<out_image_type>::pixel_type>::grayscale == true + - pixel_traits<typename image_traits<out_image_type>::pixel_type>::has_alpha == false + - pixel_traits<typename image_traits<out_image_type>::pixel_type>::is_unsigned == true + ensures + - #out_img == the thresholded version of in_img (in_img is converted to a grayscale + intensity image if it is color). Pixels in in_img with grayscale values >= thresh + have an output value of on_pixel and all others have a value of off_pixel. + - The thresh value used is determined by performing a k-means clustering + on the input image histogram with a k of 2. The point between the two + means found is used as the thresh value. + - #out_img.nc() == in_img.nc() + - #out_img.nr() == in_img.nr() + !*/ + + template < + typename image_type + > + void auto_threshold_image ( + image_type& img + ); + /*! + requires + - it is valid to call auto_threshold_image(img,img); + ensures + - calls auto_threshold_image(img,img); + !*/ + +// ---------------------------------------------------------------------------------------- + + template < + typename in_image_type, + typename out_image_type + > + void hysteresis_threshold ( + const in_image_type& in_img, + out_image_type& out_img, + typename pixel_traits<typename image_traits<in_image_type>::pixel_type>::basic_pixel_type lower_thresh, + typename pixel_traits<typename image_traits<in_image_type>::pixel_type>::basic_pixel_type upper_thresh + ); + /*! + requires + - in_image_type == is an implementation of array2d/array2d_kernel_abstract.h + - out_image_type == is an implementation of array2d/array2d_kernel_abstract.h + - pixel_traits<typename image_traits<out_image_type>::pixel_type>::grayscale == true + - pixel_traits<typename image_traits<in_image_type>::pixel_type>::has_alpha == false + - pixel_traits<typename image_traits<out_image_type>::pixel_type>::has_alpha == false + - lower_thresh <= upper_thresh + - is_same_object(in_img, out_img) == false + ensures + - #out_img == the hysteresis thresholded version of in_img (in_img is converted to a + grayscale intensity image if it is color). Pixels in in_img with grayscale + values >= upper_thresh have an output value of on_pixel and all others have a + value of off_pixel unless they are >= lower_thresh and are connected to a pixel + with a value >= upper_thresh, in which case they have a value of on_pixel. Here + pixels are connected if there is a path between them composed of pixels that + would receive an output of on_pixel. + - #out_img.nc() == in_img.nc() + - #out_img.nr() == in_img.nr() + !*/ + +// ---------------------------------------------------------------------------------------- + +} + +#endif // DLIB_THRESHOLDINg_ABSTRACT_ + + |