Added randomly_color_image()

dlib/image_transforms.h

@@ -13,6 +13,7 @@
 #include "image_transforms/integral_image.h"
 #include "image_transforms/image_pyramid.h"
 #include "image_transforms/label_connected_blobs.h"
+#include "image_transforms/randomly_color_image.h"
 
 #endif // DLIB_IMAGE_TRANSFORMs_
 

dlib/image_transforms/randomly_color_image.h

+// Copyright (C) 2011  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#ifndef DLIB_RANDOMLY_COlOR_IMAGE_H__
+#define DLIB_RANDOMLY_COlOR_IMAGE_H__
+
+#include "randomly_color_image_abstract.h"
+#include "../hash.h"
+#include "../pixel.h"
+#include "../matrix.h"
+
+namespace dlib
+{
+
+// ----------------------------------------------------------------------------------------
+
+    template <typename T>
+    struct op_randomly_color_image : does_not_alias 
+    {
+        op_randomly_color_image( const T& img_) : img(img_){}
+
+        const T& img;
+
+        const static long cost = 7;
+        const static long NR = 0;
+        const static long NC = 0;
+        typedef rgb_pixel type;
+        typedef const rgb_pixel const_ret_type;
+        typedef typename T::mem_manager_type mem_manager_type;
+        typedef row_major_layout layout_type;
+
+        const_ret_type apply (long r, long c ) const 
+        { 
+            const unsigned long gray = get_pixel_intensity(img[r][c]);
+            if (gray != 0)
+            {
+                const uint32 h = murmur_hash3(&gray, sizeof(gray));
+                rgb_pixel pix;
+                pix.red   = static_cast<unsigned char>(h)%200 + 55;
+                pix.green = static_cast<unsigned char>(h>>8)%200 + 55;
+                pix.blue  = static_cast<unsigned char>(h>>16)%200 + 55;
+                return pix;
+            }
+            else
+            {
+                // keep black pixels black
+                return rgb_pixel(0,0,0);
+            }
+        }
+
+        long nr () const { return img.nr(); }
+        long nc () const { return img.nc(); }
+    }; 
+
+    template <
+        typename image_type
+        >
+    const matrix_op<op_randomly_color_image<image_type> >  
+    randomly_color_image (
+        const image_type& img
+    )
+    {
+        typedef op_randomly_color_image<image_type> op;
+        return matrix_op<op>(op(img));
+    }
+
+// ----------------------------------------------------------------------------------------
+
+}
+
+#endif // DLIB_RANDOMLY_COlOR_IMAGE_H__
+

dlib/image_transforms/randomly_color_image_abstract.h

+// Copyright (C) 2011  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#undef DLIB_RANDOMLY_COlOR_IMAGE_ABSTRACT_H__
+#ifdef DLIB_RANDOMLY_COlOR_IMAGE_ABSTRACT_H__
+
+#include "randomly_color_image_abstract.h"
+#include "../hash.h"
+#include "../pixel.h"
+#include "../matrix.h"
+
+namespace dlib
+{
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename image_type
+        >
+    const matrix_exp randomly_color_image (
+        const image_type& img
+    );
+    /*!
+        requires
+            - image_type is an implementation of array2d/array2d_kernel_abstract.h
+            - pixel_traits<image_type::type> must be defined
+        ensures
+            - randomly generates a mapping from gray level pixel values
+              to the RGB pixel space and then uses this mapping to create
+              a colored version of img.  Returns a matrix which represents
+              this colored version of img.
+            - black pixels in img will remain black in the output image.  
+            - The returned matrix will have the same dimensions as img.
+    !*/
+
+// ----------------------------------------------------------------------------------------
+
+}
+
+#endif // DLIB_RANDOMLY_COlOR_IMAGE_ABSTRACT_H__
+
+