### Difference: LZ77 vs. LZ4 vs. LZ4HC (compression algorithms)?

I understand the LZ77 and LZ78 algorithms. I read about LZ4 here and here and found code for it.Those links described the LZ4 block format. But it would be great if someone could explain (or direct me to some resource explaining):How LZ4 is different from LZ77?How is LZ4HC different from LZ4? What idea makes the LZ4HC algorithm so fast?...Read more

### Lossless compressed JPEG gstreamer element?

The pipeline below works fine for saving compressed JPEG images but is there a way to save lossless compressed JPEG images using gstreamer? gst-launch v4l2src always-copy=false num-buffers=1 chain-ipipe=true ! 'video/x-raw-yuv,format=(fourcc)NV12, width=2176, height=1944' ! dmaiaccel ! dm365facedetect draw-square=true ! dmaienc_jpeg ! filesink location=\$FILE_NAME...Read more

### Huffman coding for Lossless Compression

I really need help with Huffman Coding for Lossless compression. I have an exam coming up and need to understand this, does anyone know of easy tutorials made to understand this, or could someone explain. The questions in the exam are likely to be: Suppose the alphabet is [A, B, C], and the known probability distribution is P(A)=0.6, P(B)=0.2 and P(C)=0.2. For simplicity, let’s also assume that both encoder and decoder know that the length of the messages is always 3, so there is no need for a terminator.How many bits are needed to encode the m...Read more

### array data compression that is holding 13268 bits(1.66kBytes)

i.e array is having 100*125 bits of data for each aircraft+8 ascii messages each of 12 characters what compression technique should i apply to such data...Read more

### Compression or encrypt data

I have two bytes and I want to compress them into a single byte using a key( key length can be up to 64 bits).And further I want to be able to retrieve the two bytes by using the compressed byte and the same key.Someone has an idea how to do that?Thanks....Read more

### Lossless data compression for extremely large data - Planetary artificial intelligence

I want to create an environment for artificial intelligence, with planetary size. It will simulate underground life on a very large world. According to Wikipedia, planet Earth has a surface area of 510,072,000 Km^2, I want to create a square of similar proportions, maybe bigger. I will store one meter on each bit, where 0 means dirt and 1 means wall of dirt.Let's first calculate how to store a single line of this square. One line would be 510072000000m and each byte can store 8 meters, so one line would be 59.38GB and the entire world would be ...Read more