Remove Dcraw binary usage

Removes dependence on the dcraw binary in order to produce a more portable binary that can be moved into other directories without errors about the location of the dcraw binary.

README.md

@@ -4,7 +4,7 @@ Note: The user "Titaniumtown" is now the primary maintainer of this repository;
 Original Document on the subject (by Timothy Brooks): http://timothybrooks.com/tech/hdr-plus
 
 ### Compilation instructions:
-1. Install libraw¹, libpng, and libjpeg.²
+1. Install libraw, libpng, and libjpeg.¹
 2. Download and compile llvm 3.9
 3. Download the "2017-05-03" source of Halide from https://github.com/halide/Halide_old_history/releases
 4. Compile Halide according to the README.md file included with the source file zip of halide.
@@ -32,9 +32,5 @@ Usage: ./hdrplus [-c comp -g gain (optional)] dir_path out_img raw_img1 raw_img2
 The -c and -g flags change the amount of dynamic range compression and gain respectively. Although they are optional because they both have default values. 
 
 ### Footnotes:
-
-¹ If you are on macOS the included dcraw binary will not work so I included the macos version in the same directory. If you are on macOS change the following "../tools/dcraw" to "../tools/dcraw_macos" in the files below before compiling:
-  - batch_dcraw.py
-  - halide_load_raw.h
 
-² Also to install libraw, libpng, and libjpeg on macOS run ```brew install libraw libpng libjpeg```
+¹Also to install libraw, libpng, and libjpeg on macOS run ```brew install libraw libpng libjpeg```

src/halide_load_raw.h

@@ -45,50 +45,19 @@ inline void swap_endian_16(uint16_t &value) {
 
 template<Internal::CheckFunc check = Internal::CheckFail>
 bool load_raw(const std::string &filename, uint16_t* data, int width, int height) {
-
-    Internal::PipeOpener f(("../tools/dcraw -c -D -6 -W -g 1 1 " + filename).c_str(), "r");
-    if (!check(f.f != nullptr, "File could not be opened for reading\n"))
-        return false;
-
-    int in_width, in_height, maxval;
-    char header[256];
-    char buf[1024];
-    bool fmt_binary = false;
-
-    f.readLine(buf, 1024);
-    if (!check(sscanf(buf, "%255s", header) == 1, "Could not read PGM header\n")) return false;
-    if (header == std::string("P5") || header == std::string("p5"))
-        fmt_binary = true;
-    if (!check(fmt_binary, "Input is not binary PGM\n")) return false;
-
-    f.readLine(buf, 1024);
-    if (!check(sscanf(buf, "%d %d\n", &in_width, &in_height) == 2, "Could not read PGM width and height\n")) return false;
-
-    if (!check(in_width == width, "Input image has width %d, but must must have width of %d\n")) return false;
-
-    if (!check(in_height == height, "Input image '%s' has height %d, but must must have height of %d\n")) return false;
-
-    f.readLine(buf, 1024);
-    if (!check(sscanf(buf, "%d", &maxval) == 1, "Could not read PGM max value\n")) return false;
-
-    if (!check(maxval == 65535, "Invalid bit depth (not 16 bits) in PGM\n")) return false;
-
-    if (!check(fread((void *) data, sizeof(uint16_t), width*height, f.f) == (size_t) (width*height), "Could not read PGM 16-bit data\n")) return false;
-
-    if (is_little_endian()) {
-
-        for (int y = 0; y < height; y++) {
-            for (int x = 0; x < width; x++) {
-
-                swap_endian_16(data[y * width + x]);
-            }
-        }
+    LibRaw RawProcessor;
+    int ret = RawProcessor.dcraw_process();
+
+    if (LIBRAW_SUCCESS != ret)
+    {
+        fprintf(stderr, "Cannot open %s: %s\n", filename, libraw_strerror(ret));
+        return ret;
     }
-
+    
     return true;
 }
 
 } // namespace Tools
 } // namespace Halide
 
-#endif
+#endif