- From: Dr. Olaf Hoffmann <Dr.O.Hoffmann@gmx.de>
- Date: Sun, 13 Jun 2010 15:05:36 +0200
- To: www-svg@w3.org
Hello www-svg, within the definition of the attribute type for the elements feFunc* http://www.w3.org/TR/SVG11/filters.html#feComponentTransferTypeAttribute there seem to be some variables in the formulas undefined. Is my interpretation correct, that C and C' correspond to the relative channel value the subelement represents? Between 0 and 1? Colors have to be transformed to this range? C before, C' after transformation? For example for feFuncR this means the relative value of the red channel? And what exactly is N? My assumption is, that it is N = n. Is this correct? At least the formulas for table and discrete look useful for C from the interval [0;1) For C = 1 the formulas have the problem, that the v(n+1) for table does not exist and v(n) not for discrete. k is one too large, there is a need to provide another formula for C=1 - something like: use formulas for [0;1) and v(n) for C=1 for table and v(n-1) for C=1 for discrete. For the table type this is only a formal problem, because (C-k/N) = 0 anyway, whatever v(n+1) might be; the result is C' = v(n). Nevertheless the formula should not contain the undefined v(n+1). For the discrete type C'=v(n) for C=1 resulting in k=N is a problem, because the v(i) are defined in such a way, that the last value is v(n-1). Best wishes Olaf
Received on Sunday, 13 June 2010 13:18:57 UTC