Please someone could explain me why some rar files containing jpg images opens in sumatra and other files generated with jpg images do not open.
What is needed in the winrar setup so that it opens perfectly in sumatra.
Thank you very much
Gerson
Some Rar files are different formats and there have been some recent changes with cbr version handling that requires an external dll for support of some Rar V5 files.
Sumatra is not a .RAR wrapper opener as such it expects .CBR files to be well structured in conformance with earlier version 4 however it can attempt to use an adjacent alternative Version 5 unrar.dll
There are some open (and closed) issues since the last formal 3.1.2 so it is always worth testing the latest pre-release however note that the extra unrar.dll may be unpacked to an unfamiliar location see https://github.com/sumatrapdfreader/sumatrapdf/issues/1116
The contents of the .cbr should for lossless quality be png or at worst standard lossy jpg any higher proprietary compression such as wavelets or jbig 2000 are likely to cause problems on decompression (it makes no sense to compress documents heavily since it impacts reading performance) compression is really only of value for transmittal or archive uses.