Image Conversion on Multiple Threads

[sibo]

Hello,

I am trying to use several threads to convert images from Nikon's NEF format to TIFF using ImgSource v5 and SARAW 2.2 (both are the latest versions), but the resulting images are corrupt. This works if I convert a single image at a time, but not when I run multiple threads...

I initialise the libraries once using:

is5_Initialize();
SARAW_Initialize();

Then on each thread I set the hooks using:

if (HISEXTHK hHk = is5_GetExtHook(0))
{

SARAW_SetImgSourceHooks(hHk);
GlobalFree(hHk);

}

and then convert the NEF image to TIFF using:

if (HISSRC hSrc = is5_OpenFileSourceW(pNefFile))
{

UINT32 uiW = 0;
UINT32 uiH = 0;
if (HGLOBAL hImg = SARAW_ReadRAW(hSrc, &uiW, &uiH, 24, 1.0, 3, -1, 0, 0, 0, 0, (1<< 9)))
{

if (HISDEST hDest = is5_OpenFileDestW(pTiffFile, FALSE))
{

is5_WriteTIFF(hDest, (BYTE*) hImg, uiW, uiH, 24, uiW*3, 0, 1, 0, 0);
is5_CloseDest(hDest);

}
GlobalFree(hImg);

}
is5_CloseSource(hSrc);

}

Can anyone see what I have done wrong please?

[Admin]

i don't see anything obviously wrong with your code.

just as an experiment, do you get good output files if you convert JPG or BMP to TIFF (ex. replace that SARAW call with is5_ReadJPG, or is5_ReadBMP) ? just wondering if the problem is in SARAW...

[sibo]

Hi there,

I've just tried your suggestion of converting JPG and BMP images into TIFF on 2 parallel threads within the same process - both of these work correctly. So this would suggest that there seems to be a problem with SARAW.

Do you have any suggestions?

Regards,
sibo

[sibo]

Hi,

I've just tried to reply, but my post has disappeared, so I'll try again.

I tried to convert JPG and BMP images into TIFF format on 2 concurrent threads within the same process and I got the correct results. So does this suggest that there is indeed a problem with SARAW?

Do you have any suggestions to fix the situation

Regards,
sibo

[Admin]

i'm going to have to take a look at the SARAW code to see what's going on. AFAIK, the code is thread-safe. but obviously it might not be.

[Admin]

also... do you know which camera(s) your RAW files came from ?
(helps to know which decoder to focus on)

[Admin]

hi,
we've just uploaded a new SARAW package (v2.2.6.2). this should fix the problem you're seeing.

[sibo]

It was taken from a D90.

[sibo]

Great thank you very much - now that's good service!

[sibo]

Hi,

I can confirm that this fix works in my application - many thanks for your prompt attention.

Regards,
sibo