How to read and write the image data void *inData in the filter plug-in?

[_fiona_guo_]

In the filter plug-in, void *inData in the struct FilterRecord is the pointer to the requested input image data. How to read and write it? In another word, how to translate it to unsigned char * data?

[qu1j0t3]

Use a cast, or assign to a pointer with your desired type.

For a large number of examples, see my source code at http://telegraphics.com.au/sw/

E.g., usage of inData in simple filters such as https://www.telegraphics.com.au/fisheye/browse/12bits/trunk/main.c?r=12#l248

You will also want to do this if you're accessing 16 bit data (unsigned short).

[_fiona_guo_]

Thanks for you help.Could you explain it more particular?
Now my code is like this:
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FILE *fp;
fp=fopen("C:\\h.bmp","w+r");
fseek(fp, 55, SEEK_SET);
fwrite((unsigned char*)gStuff->inData, 1, gStuff->bigDocumentData-> wholeSize32.v * gStuff->bigDocumentData->wholeSize32.h * gStuff->planes, fp);
fclose(fp);

-------------------------------------------
Why the image data saved is disordered?
Thanks.