Hi all,<div><br></div><div>Johannes & I were discussing how the speed of the Bio-Formats TIFF reader could be improved in common cases. Two main ideas:</div><div><br></div><div>1) If the data was written by either ImageJ or Bio-Formats (either which can be detected by examining the first IFD), we could make assumptions about the structure of the pixel data. ImageJ itself does this when reading TIFF files (assumes planes are written in contiguous order) which allows it to read in TIFFs very quickly. Unfortunately, ImageJ fails to handle TIFFs that do not meet these assumptions. But Bio-Formats could fall back to its more general parsing logic.</div>
<div><br></div><div>2) Parse IFDs only lazily per plane as each plane is requested, rather than fully populating them all up front. AFAIK, the first IFD is really the only important one for detecting whether a file should be classified as a particular subtype of TIFF. Also AFAIK, we would still need to walk the IFD linked list just to count the total number of image planes (unless we could obtain that information in some other format-specific way), but it would probably be faster than parsing all IFDs fully up-front.</div>
<div><br></div><div>We think that Bio-Formats could deliver the best of both worlds (correctness and performance), if we added some heuristics along these lines in common cases. It could make a big difference in usability.</div>
<div><br></div><div>Do other Bio-Formats devs agree? If so, I can file a ticket on the OME Trac for it, if one doesn't already exist.</div><div><br></div><div>Regards,</div><div>Curtis</div><div><br></div>