in tools/im2rec.cc [70:340]
int main(int argc, char* argv[]) {
if (argc < 4) {
printf(
"Usage: <image.lst> <image_root_dir> <output.rec> [additional parameters in form "
"key=value]\n"
"Possible additional parameters:\n"
"\tcolor=USE_COLOR[default=1] Force color (1), gray image (0) or keep source unchanged "
"(-1).\n"
"\tresize=newsize resize the shorter edge of image to the newsize, original images will be "
"packed by default\n"
"\tlabel_width=WIDTH[default=1] specify the label_width in the list, by default set to 1\n"
"\tpack_label=PACK_LABEL[default=0] whether to also pack multi dimenional label in the "
"record file\n"
"\tnsplit=NSPLIT[default=1] used for part generation, logically split the image.list to "
"NSPLIT parts by position\n"
"\tpart=PART[default=0] used for part generation, pack the images from the specific part "
"in image.list\n"
"\tcenter_crop=CENTER_CROP[default=0] specify whether to crop the center image to make it "
"square.\n"
"\tquality=QUALITY[default=95] JPEG quality for encoding (1-100, default: 95) or PNG "
"compression for encoding (1-9, default: 3).\n"
"\tencoding=ENCODING[default='.jpg'] Encoding type. Can be '.jpg' or '.png'\n"
"\tinter_method=INTER_METHOD[default=1] NN(0) BILINEAR(1) CUBIC(2) AREA(3) LANCZOS4(4) "
"AUTO(9) RAND(10).\n"
"\tunchanged=UNCHANGED[default=0] Keep the original image encoding, size and color. If set "
"to 1, it will ignore the others parameters.\n");
return 0;
}
int label_width = 1;
int pack_label = 0;
int new_size = -1;
int nsplit = 1;
int partid = 0;
int center_crop = 0;
int quality = 95;
int color_mode = CV_LOAD_IMAGE_COLOR;
int unchanged = 0;
int inter_method = CV_INTER_LINEAR;
std::string encoding(".jpg");
for (int i = 4; i < argc; ++i) {
char key[128], val[128];
int effct_len = 0;
#ifdef _MSC_VER
effct_len = sscanf_s(argv[i], "%[^=]=%s", key, sizeof(key), val, sizeof(val));
#else
effct_len = sscanf(argv[i], "%[^=]=%s", key, val);
#endif
if (effct_len == 2) {
if (!strcmp(key, "resize"))
new_size = atoi(val);
if (!strcmp(key, "label_width"))
label_width = atoi(val);
if (!strcmp(key, "pack_label"))
pack_label = atoi(val);
if (!strcmp(key, "nsplit"))
nsplit = atoi(val);
if (!strcmp(key, "part"))
partid = atoi(val);
if (!strcmp(key, "center_crop"))
center_crop = atoi(val);
if (!strcmp(key, "quality"))
quality = atoi(val);
if (!strcmp(key, "color"))
color_mode = atoi(val);
if (!strcmp(key, "encoding"))
encoding = std::string(val);
if (!strcmp(key, "unchanged"))
unchanged = atoi(val);
if (!strcmp(key, "inter_method"))
inter_method = atoi(val);
}
}
// Check parameters ranges
if (color_mode != -1 && color_mode != 0 && color_mode != 1) {
LOG(FATAL) << "Color mode must be -1, 0 or 1.";
}
if (encoding != std::string(".jpg") && encoding != std::string(".png")) {
LOG(FATAL) << "Encoding mode must be .jpg or .png.";
}
if (label_width <= 1 && pack_label) {
LOG(FATAL) << "pack_label can only be used when label_width > 1";
}
if (new_size > 0) {
LOG(INFO) << "New Image Size: Short Edge " << new_size;
} else {
LOG(INFO) << "Keep origin image size";
}
if (center_crop) {
LOG(INFO) << "Center cropping to square";
}
if (color_mode == 0) {
LOG(INFO) << "Use gray images";
}
if (color_mode == -1) {
LOG(INFO) << "Keep original color mode";
}
LOG(INFO) << "Encoding is " << encoding;
if (encoding == std::string(".png") && quality > 9) {
quality = 3;
}
if (inter_method != 1) {
switch (inter_method) {
case 0:
LOG(INFO) << "Use inter_method CV_INTER_NN";
break;
case 2:
LOG(INFO) << "Use inter_method CV_INTER_CUBIC";
break;
case 3:
LOG(INFO) << "Use inter_method CV_INTER_AREA";
break;
case 4:
LOG(INFO) << "Use inter_method CV_INTER_LANCZOS4";
break;
case 9:
LOG(INFO) << "Use inter_method mod auto(cubic for enlarge, area for shrink)";
break;
case 10:
LOG(INFO) << "Use inter_method mod rand(nn/bilinear/cubic/area/lanczos4)";
break;
default:
LOG(INFO) << "Unkown inter_method";
return 0;
}
}
std::random_device rd;
std::mt19937 prnd(rd());
using namespace dmlc;
const static size_t kBufferSize = 1 << 20UL;
std::string root = argv[2];
mxnet::io::ImageRecordIO rec;
size_t imcnt = 0;
double tstart = dmlc::GetTime();
dmlc::InputSplit* flist = dmlc::InputSplit::Create(argv[1], partid, nsplit, "text");
std::ostringstream os;
if (nsplit == 1) {
os << argv[3];
} else {
os << argv[3] << ".part" << std::setw(3) << std::setfill('0') << partid;
}
LOG(INFO) << "Write to output: " << os.str();
dmlc::Stream* fo = dmlc::Stream::Create(os.str().c_str(), "w");
LOG(INFO) << "Output: " << os.str();
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;
if (encoding == std::string(".png")) {
encode_params.push_back(CV_IMWRITE_PNG_COMPRESSION);
encode_params.push_back(quality);
LOG(INFO) << "PNG encoding compression: " << quality;
} else {
encode_params.push_back(CV_IMWRITE_JPEG_QUALITY);
encode_params.push_back(quality);
LOG(INFO) << "JPEG encoding quality: " << quality;
}
dmlc::InputSplit::Blob line;
std::vector<float> label_buf(label_width, 0.f);
while (flist->NextRecord(&line)) {
std::string sline(static_cast<char*>(line.dptr), line.size);
std::istringstream is(sline);
if (!(is >> rec.header.image_id[0] >> rec.header.label))
continue;
label_buf[0] = rec.header.label;
for (int k = 1; k < label_width; ++k) {
CHECK(is >> label_buf[k]) << "Invalid ImageList, did you provide the correct label_width?";
}
if (pack_label)
rec.header.flag = label_width;
rec.SaveHeader(&blob);
if (pack_label) {
size_t bsize = blob.size();
blob.resize(bsize + label_buf.size() * sizeof(float));
memcpy(BeginPtr(blob) + bsize, BeginPtr(label_buf), label_buf.size() * sizeof(float));
}
CHECK(std::getline(is, fname));
// eliminate invalid chars in the end
while (fname.length() != 0 && (isspace(*fname.rbegin()) || !isprint(*fname.rbegin()))) {
fname.resize(fname.length() - 1);
}
// eliminate invalid chars in beginning.
const char* p = fname.c_str();
while (isspace(*p))
++p;
path = root + p;
// use "r" is equal to rb in dmlc::Stream
dmlc::Stream* fi = dmlc::Stream::Create(path.c_str(), "r");
decode_buf.clear();
size_t imsize = 0;
while (true) {
decode_buf.resize(imsize + kBufferSize);
size_t nread = fi->Read(BeginPtr(decode_buf) + imsize, kBufferSize);
imsize += nread;
decode_buf.resize(imsize);
if (nread != kBufferSize)
break;
}
delete fi;
if (unchanged != 1) {
cv::Mat img = cv::imdecode(decode_buf, color_mode);
CHECK(img.data != nullptr) << "OpenCV decode fail:" << path;
cv::Mat res = img;
if (new_size > 0) {
if (center_crop) {
if (img.rows > img.cols) {
int margin = (img.rows - img.cols) / 2;
img = img(cv::Range(margin, margin + img.cols), cv::Range(0, img.cols));
} else {
int margin = (img.cols - img.rows) / 2;
img = img(cv::Range(0, img.rows), cv::Range(margin, margin + img.rows));
}
}
int interpolation_method = 1;
if (img.rows > img.cols) {
if (img.cols != new_size) {
interpolation_method = GetInterMethod(
inter_method, img.cols, img.rows, new_size, img.rows * new_size / img.cols, prnd);
cv::resize(img,
res,
cv::Size(new_size, img.rows * new_size / img.cols),
0,
0,
interpolation_method);
} else {
res = img.clone();
}
} else {
if (img.rows != new_size) {
interpolation_method = GetInterMethod(
inter_method, img.cols, img.rows, new_size * img.cols / img.rows, new_size, prnd);
cv::resize(img,
res,
cv::Size(new_size * img.cols / img.rows, new_size),
0,
0,
interpolation_method);
} else {
res = img.clone();
}
}
}
encode_buf.clear();
CHECK(cv::imencode(encoding, res, encode_buf, encode_params));
// write buffer
size_t bsize = blob.size();
blob.resize(bsize + encode_buf.size());
memcpy(BeginPtr(blob) + bsize, BeginPtr(encode_buf), encode_buf.size());
} else {
size_t bsize = blob.size();
blob.resize(bsize + decode_buf.size());
memcpy(BeginPtr(blob) + bsize, BeginPtr(decode_buf), decode_buf.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) << "Total: " << imcnt << " images processed, " << GetTime() - tstart << " sec elapsed";
delete fo;
delete flist;
return 0;
}