Nothing has changed in the code in the past year or so with regard to converting images, so let's see if we can figure this out. I ran a test with 112 TIFFs that I converted to JPEG and checked the memory before, during, and after, and I'm not seeing any memory leaks or other problems. Unfortunately it can be complicated with TIFFs because their headers can be so complex that it's almost like running unspecified code: and that code can sometimes cause problems. This is why Fred asked where the TIFFs came from; what he meant was... what software was used to create the TIFFs? My first suspicion is that you have some TIFFs that have bad headers or have header info that Qimage can't handle for some reason (they are not compatible). See if you can narrow down the problem. That is, when you try to convert some TIFFs and you run into this problem, try splitting them into two halves: does the error only happen when one of the two batches of 20 is converted? If so, split that bad batch of 20 into 10/10 and repeat. See if you can find the problem TIFF(s): there may only be one... or a few. If you can find one, you can send it to me and I'll see if I can find what is causing the problem.
Regards,
Mike