Well if there are 4x 8 bit values (RGB+alpha) =32 bits trying to be encoded/decoded into a single precision float, there will be loss of fidelity.
It amazes me that it works for encoding 24 bit values (I tested it for RGB only and can send a demo patch, or check the one Katja posted here: http://lists.puredata.info/pipermail/pd-list/2015-12/112694.html )
Check out Katja's page and video about "Pd Double" for the best explanation of this problem.
I personally wish there was a 32 bit integer data type in Pd for counters and binary registers and such, which I know will never get converted into floats, and risk strange rounding errors or noise in the Least Significant Bits.
On Thursday, December 31, 2015, João Pais jmmmpais@gmail.com wrote:
Ok. Do you know what should be done to convert to Pd's rgb format?
I'm pretty sure the 4th value is alpha
Sent from my iPhone
On Dec 31, 2015, at 7:53 AM, João Pais jmmmpais@gmail.com wrote:
Hello list,
I'm trying to use [pix_data] to get the RGB values from an image, and
color a canvas using them. But the results come out a bit weird, as not all colors match.
I can try to some a more detailed patch in a couple of days, but wanted
to ask first the there is any example of how to use the values coming out of [pix_data]:
- should the gray value be used?
- the middle outlet should send a list of RGB values, but I noticed
that instead a list of 4 values comes out. This isn't documented, what is the 4th value?
Attached are 2 pictures that should exemplifiy the issue:
- rgb.tif - a rgb palette
- rgb-conv.tif - the result after my interpretation of the data
Best,
Joao <rgb.tif> <rgb-conv.tif> _______________________________________________ Pd-list@lists.iem.at mailing list UNSUBSCRIBE and account-management ->
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