How about a concrete example? For some reason I once did a little program to convert between RGB and HSB. It's on my home site, and every now and again I get a query like this one:
> Hello, > I just found your web page with the Java [Javascript, actually. TG] applet that converts between > RGB and HSI. I am very curious about which equations you used for the HSI > to RGB transformation. It seems to me that there is an error or at least > something misleading in the equations given in Digital Image Processing, > second ed., by Rafael Gonzalez -- it's been my main reference, and it > seems that most people on the web have copied the text verbatim without > noticing the mistakes. There is an erratta to the text on the book > website, but even with the fixes there still seems to be trouble. > > Can you point me in the right direction? I looked for the posting by > Roger Jones you reference, but I can't find it. I am developing > an application that needs to produce RGB colors based on hue for a GUI > element, so these equations would be useful to me. > > My main problem with the equations I find in the web is that although they > claim to given normalized RGB values between 0 and 1, the term with the > cosines often gives values greater than 1 (or greater than 1/3, depending > on where multiplication by 3I happens...) Well, I did my little script by finding someone else's and translating it. I don't know how to help this guy. This seems a good example of where fluency with algebra (not even very advanced algebra, I suspect) would be useful, and is therefore an example in support of some mathematical know-how. But what I think it illustrates is that the discussion is rather too high level so far. Some domains need a lot of maths, some not very much. And BTW, does anybody know what I should tell my enquirer? Thomas Green - Automatic footer for [EMAIL PROTECTED] ---------------------------------- To unsubscribe from this list, mail [EMAIL PROTECTED] unsubscribe discuss To join the announcements list, mail [EMAIL PROTECTED] subscribe announce To receive a help file, mail [EMAIL PROTECTED] help This list is archived at http://www.mail-archive.com/discuss%40ppig.org/ If you have any problems or questions, please mail [EMAIL PROTECTED]
