Thanks for your answer ! Imager and PDL are nice modules. I did not know them up to now. Really worth to invest some time.

It took me a while to install Imager. The problem was that the libpng was missing ..... But now its running.

$data =~ tr/\0\377/01/;

can be removed, if the ascii code is already used in the "if" of transform2:

49 48 if

I could not manage to install PDL yet. Prerequisite 'Module::Compile' is not passing for WIN 10 (report). Only one test is failing.(data1_t). Any idea what I could do here ? Force install ?

I saw also minor differences in the output of my code and yours. I guess that the decoding of the PNG is done minor differently in the different modules. I have to read more about png coding if this idea can be true or compare the color at some dedicated pixels.

In reply to Re^2: working with png data by Anonymous Monk
in thread working with png data by Anonymous Monk

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