Extend pHash interface with ph_mh_imagehash_from_buffer (#1)

ChangeLog

@@ -2,6 +2,10 @@
 ---
 GitHub release
 
+0.9.8
+---
+Extend pHash interface with ph_mh_imagehash_from_buffer
+
 0.9.7
 ---
 JNI code cleanup

libpHash.spec

@@ -1,5 +1,5 @@
 Name:           pHash
-Version:        0.9.7
+Version:        0.9.8
 Release:        1%{?dist}
 Summary:        pHash, the open source perceptual hashing library
 

src/pHash.cpp

@@ -615,8 +615,6 @@ uint8_t *ph_mh_imagehash(const char *filename, int &N, float alpha, float lvl) {
     if (filename == NULL) {
         return NULL;
     }
-    uint8_t *hash = (unsigned char *)malloc(72 * sizeof(uint8_t));
-    N = 72;
 
     CImg<uint8_t> src(filename);
     CImg<uint8_t> img;
@@ -635,6 +633,14 @@ uint8_t *ph_mh_imagehash(const char *filename, int &N, float alpha, float lvl) {
     }
     src.clear();
 
+    return ph_mh_imagehash_from_buffer(img, N, alpha, lvl);
+}
+
+uint8_t *ph_mh_imagehash_from_buffer(CImg<uint8_t> &img, int &N, float alpha,
+                                     float lvl) {
+    uint8_t *hash = (unsigned char *)malloc(72 * sizeof(uint8_t));
+    N = 72;
+
     CImg<float> *pkernel = GetMHKernel(alpha, lvl);
     CImg<float> fresp = img.get_correlate(*pkernel);
     img.clear();

src/pHash.h.cmake

@@ -254,6 +254,15 @@ int ph_hamming_distance(const ulong64 hash1,const ulong64 hash2);
 **/
 uint8_t* ph_mh_imagehash(const char *filename, int &N, float alpha=2.0f, float lvl = 1.0f);
 
+/** /brief create MH image hash from image buffer
+*   /param img - image buffer
+*   /param N - (out) int value for length of image hash returned
+*   /param alpha - int scale factor for marr wavelet (default=2)
+*   /param lvl   - int level of scale factor (default = 1)
+*   /return uint8_t array
+**/
+uint8_t* ph_mh_imagehash_from_buffer(CImg<uint8_t> &img, int &N, float alpha=2.0f, float lvl = 1.0f);
+
 /** /brief count number bits set in given byte
 *   /param val - uint8_t byte value
 *   /return int value for number of bits set