2015.01.01 20:24 "Re: [Tiff] Fast TIFF Reading on Windows", by Aaron Boxer

2015.01.05 13:47 "[Tiff] Fwd: Fast TIFF Reading on Windows", by Aaron Boxer

---------- Forwarded message ----------

On Sun, Jan 4, 2015 at 11:49 PM, Bob Friesenhahn < bfriesen@simple.dallas.tx.us> wrote:

> On Sun, 4 Jan 2015, Aaron Boxer wrote:
>
> Another finding: reading files with four threads (I have a quad core i7)
>> is about twice as fast as single threaded
>> reads.
>>
>

> With this approach do you have one thread calling libtiff APIs at a time?

With the threaded approach, I have a thread safe list of files in a directory, and each thread gets the next file name in the list and loads with libtiff. So, yes, I haven't changes the library, just calling it from multiple threads.

What would be interesting is to use multiple threads to read a single TIFF image. This would be particularly advantageous for BigTIFF. My library is using C++11, so threading support is baked in. Its quite easy, keeping in mind that threads are evil.

For libtiff, one would need to find a good cross platform C threading library.

For a single file, the approach could be similar: a thread safe list of strips, and each thread gets the next strip and reads it in.

Aaron