public MnistImage [] Read(int batchSize)
{
var result = new MnistImage [batchSize];
if (start + batchSize < source.Length)
{
Array.Copy(source, start, result, 0, batchSize);
start += batchSize;
}
else
{
var firstLength = source.Length - start;
Array.Copy(source, start, result, 0, firstLength);
Array.Copy(source, 0, result, firstLength, batchSize - firstLength);
start = firstLength;
}
return(result);
}
MnistImage [] ExtractImages(Stream input, string file)
{
using (var gz = new GZipStream(input, CompressionMode.Decompress)) {
if (Read32(gz) != 2051)
{
throw new Exception("Invalid magic number found on the MNIST " + file);
}
var count = Read32(gz);
var rows = Read32(gz);
var cols = Read32(gz);
var result = new MnistImage [count];
for (int i = 0; i < count; i++)
{
var size = rows * cols;
var data = new byte [size];
gz.Read(data, 0, size);
result [i] = new MnistImage(cols, rows, data);
}
return(result);
}
}