add support for RVL depth image compression (#1409)

* add rvl_codec * add support for RVL deep image compression * DBViewer: edit depth re-using same compression format than the one in database. * Fixing windows ci * 💄 * missing dll export (windows) * typo --------- Co-authored-by: matlabbe <[email protected]>
2026-10-06 01:57:45 +08:00 · 2024-12-15 18:35:05 -08:00
parent 02e30ffc69
commit 89849ae245
16 changed files with 325 additions and 52 deletions
@@ -0,0 +1,102 @@
+// The following code is a C++ wrapper of the code presented by
+// Andrew D. Wilson in "Fast Lossless Depth Image Compression" at SIGCHI'17.
+// The original code is licensed under the MIT License.
+
+#include <rtabmap/core/rvl_codec.h>
+
+namespace rtabmap
+{
+
+RvlCodec::RvlCodec() {}
+
+void RvlCodec::EncodeVLE(int value)
+{
+    do
+    {
+        int nibble = value & 0x7;  // lower 3 bits
+        if (value >>= 3)
+            nibble |= 0x8;  // more to come
+        word_ <<= 4;
+        word_ |= nibble;
+        if (++nibblesWritten_ == 8)  // output word
+        {
+            *pBuffer_++ = word_;
+            nibblesWritten_ = 0;
+            word_ = 0;
+        }
+    } while (value);
+}
+
+int RvlCodec::DecodeVLE()
+{
+    unsigned int nibble;
+    int value = 0, bits = 29;
+    do
+    {
+        if (!nibblesWritten_)
+        {
+            word_ = *pBuffer_++;  // load word
+            nibblesWritten_ = 8;
+        }
+        nibble = word_ & 0xf0000000;
+        value |= (nibble << 1) >> bits;
+        word_ <<= 4;
+        nibblesWritten_--;
+        bits -= 3;
+    } while (nibble & 0x80000000);
+    return value;
+}
+
+int RvlCodec::CompressRVL(const uint16_t * input, unsigned char * output, int numPixels)
+{
+    buffer_ = pBuffer_ = reinterpret_cast<int *>(output);
+    nibblesWritten_ = 0;
+    const uint16_t * end = input + numPixels;
+    uint16_t previous = 0;
+    while (input != end)
+    {
+        int zeros = 0, nonzeros = 0;
+        for (; (input != end) && !*input; input++, zeros++) {}
+        EncodeVLE(zeros);  // number of zeros
+        for (const uint16_t * p = input; (p != end) && *p++; nonzeros++) {}
+        EncodeVLE(nonzeros);  // number of nonzeros
+        for (int i = 0; i < nonzeros; i++)
+        {
+            uint16_t current = *input++;
+            int delta = current - previous;
+            int positive = (delta << 1) ^ (delta >> 31);
+            EncodeVLE(positive);  // nonzero value
+            previous = current;
+        }
+    }
+    if (nibblesWritten_)  // last few values
+        *pBuffer_++ = word_ << 4 * (8 - nibblesWritten_);
+    return static_cast<int>((unsigned char *)pBuffer_ - (unsigned char *)buffer_);  // num bytes
+}
+
+void RvlCodec::DecompressRVL(const unsigned char * input, uint16_t * output, int numPixels)
+{
+    buffer_ = pBuffer_ = const_cast<int *>(reinterpret_cast<const int *>(input));
+    nibblesWritten_ = 0;
+    uint16_t current, previous = 0;
+    int numPixelsToDecode = numPixels;
+    while (numPixelsToDecode)
+    {
+        int zeros = DecodeVLE();  // number of zeros
+        numPixelsToDecode -= zeros;
+        for (; zeros; zeros--) 
+            *output++ = 0;
+        int nonzeros = DecodeVLE();  // number of nonzeros
+        numPixelsToDecode -= nonzeros;
+        for (; nonzeros; nonzeros--)
+        {
+            int positive = DecodeVLE();  // nonzero value
+            int delta = (positive >> 1) ^ -(positive & 1);
+            current = previous + delta;
+            *output++ = current;
+            previous = current;
+        }
+    }
+}
+
+}  // namespace rtabmap