/// <summary>
/// Constructs an empty chunk
/// </summary>
/// <param name="id"></param>
/// <param name="imgInfo"></param>
protected PngChunk(string id, ImageInfo imgInfo)
{
Id = id;
ImgInfo = imgInfo;
Crit = ChunkHelper.IsCritical(id);
Pub = ChunkHelper.IsPublic(id);
Safe = ChunkHelper.IsSafeToCopy(id);
Priority = false;
ChunkGroup = -1;
Length = -1;
Offset = 0;
}