add opencv resize

tools/im2rec.cc

@@ -5,35 +5,49 @@
  *  Image Record Format: zeropad[64bit] imid[64bit] img-binary-content
  *  The 64bit zero pad was reserved for future purposes
  *
- *  Image List Format: unique-image-index label path-to-image
+ *  Image List Format: unique-image-index label[s] path-to-image
  * \sa dmlc/recordio.h
  */
 #include <cctype>
+#include <cstring>
+#include <vector>
 #include <dmlc/base.h>
 #include <dmlc/io.h>
 #include <dmlc/timer.h>
 #include <dmlc/logging.h>
 #include <dmlc/recordio.h>
+#include <opencv2/opencv.hpp>
 #include "../src/io/image_recordio.h"
 
 int main(int argc, char *argv[]) {
   if (argc < 4) {
-    fprintf(stderr, "Usage: <image.lst> <image_root_dir> <output_file> [label_width=1]\n");
+    fprintf(stderr, "Usage: <image.lst> <image_root_dir> <output_file> <new_img_size/-1(do nothing)]> [label_width=1]\n");
     return 0;
   }
   int label_width = 1;
-  if (argc > 4) label_width = atoi(argv[4]);
+  int new_size = atoi(argv[4]);
+  if (new_size > 0) {
+    LOG(INFO) << "New Image Size: " << new_size << "x" << new_size;
+  } else {
+    LOG(INFO) << "Keep origin image size";
+  }
+  if (argc > 5) label_width = atoi(argv[5]);
   using namespace dmlc;
   const static size_t kBufferSize = 1 << 20UL;
   std::string root = argv[2];
   cxxnet::ImageRecordIO rec;
   size_t imcnt = 0;
-  double tstart = dmlc::GetTime();  
+  double tstart = dmlc::GetTime();
   dmlc::Stream *flist = dmlc::Stream::Create(argv[1], "r");
   dmlc::istream is(flist);
   dmlc::Stream *fo = dmlc::Stream::Create(argv[3], "w");
   dmlc::RecordIOWriter writer(fo);
   std::string fname, path, blob;
+  std::vector<unsigned char> decode_buf;
+  std::vector<unsigned char> encode_buf;
+  std::vector<int> encode_params;
+  encode_params.push_back(CV_IMWRITE_JPEG_QUALITY);
+  encode_params.push_back(100);
   while (is >> rec.header.image_id[0] >> rec.header.label) {
     for (int k = 1; k < label_width; ++ k) {
       float tmp;
@@ -44,21 +58,33 @@ int main(int argc, char *argv[]) {
     const char *p = fname.c_str();
     while (isspace(*p)) ++p;
     path = root + p;
-    dmlc::Stream *fi = dmlc::Stream::Create(path.c_str(), "r");
+    dmlc::Stream *fi = dmlc::Stream::Create(path.c_str(), "rb");
     rec.SaveHeader(&blob);
     size_t size = blob.length();
     while (true) {
-      blob.resize(size + kBufferSize);
-      size_t nread = fi->Read(BeginPtr(blob) + size, kBufferSize);
-      size += nread;
+      decode_buf.clear();
+      decode_buf.resize(kBufferSize);
+      size_t nread = fi->Read(BeginPtr(decode_buf), kBufferSize);
+      decode_buf.resize(nread);
+      cv::Mat img = cv::imdecode(decode_buf, CV_LOAD_IMAGE_COLOR);
+      cv::Mat res;
+      if (new_size > 0) {
+        cv::resize(img, res, cv::Size(new_size, new_size), 0, 0, CV_INTER_CUBIC);
+      } else {
+        res = img;
+      }
+      encode_buf.clear();
+      CHECK(cv::imencode(".jpg", res, encode_buf, encode_params));
+      blob.resize(size + encode_buf.size());
+      memcpy(BeginPtr(blob) + size, BeginPtr(encode_buf), encode_buf.size());
       if (nread != kBufferSize)  break;
     }
     delete fi;
-    writer.WriteRecord(BeginPtr(blob), size);
+    writer.WriteRecord(BeginPtr(blob), blob.size());
     // write header
     ++imcnt;
     if (imcnt % 1000 == 0) {
-      LOG(INFO) << imcnt << " images processed, " << GetTime() - tstart << " sec elapsed"; 
+      LOG(INFO) << imcnt << " images processed, " << GetTime() - tstart << " sec elapsed";
     }
   }
   delete fo;