Hallöchen! Helmut Jarausch writes:
> I wonder why lensfun uses a set parameters - in case of my > Panasonic DMC-FZ1000 > > <distortion model="ptlens" focal="9.1" a="0.01858" b="-0.05809" > c="-0.06581" /> > <distortion model="ptlens" focal="10.1" a="0.01914" b="-0.06488" > c="-0.03567" /> > <distortion model="ptlens" focal="12.6" a="0.01159" b="-0.0477" > c="-0.00043" /> > <distortion model="ptlens" focal="18.2" a="0" b="-0.00914" c="0" > /> > <distortion model="ptlens" focal="26.3" a="0" b="-0.00224" c="0" > /> > <distortion model="ptlens" focal="65.8" a="0" b="0.00035" c="0" /> > <distortion model="ptlens" focal="109.3" a="0" b="0.00049" c="0" > /> > <distortion model="ptlens" focal="146" a="0" b="-0.00305" c="0" /> > <tca model="poly3" focal="9.1" vr="1.0004262" vb="1.0003030" /> > <tca model="poly3" focal="9.1" vr="1.0004371" vb="1.0003172" /> > <tca model="poly3" focal="10.1" vr="1.0003178" vb="1.0001682" /> > <tca model="poly3" focal="12.6" vr="1.0003066" vb="1.0001788" /> > <tca model="poly3" focal="18.2" vr="1.0002344" vb="1.0002283" /> > <tca model="poly3" focal="18.2" vr="1.0002353" vb="1.0002221" /> > <tca model="poly3" focal="18.2" vr="1.0002476" vb="1.0002138" /> > <tca model="poly3" focal="26.3" vr="1.0001965" vb="1.0001175" /> > <tca model="poly3" focal="65.8" vr="1.0000103" vb="0.9999799" /> > <tca model="poly3" focal="109.3" vr="0.9999002" vb="0.9999031" /> > <tca model="poly3" focal="146" vr="0.9997527" vb="0.9998454" /> > > Aren't the lens correction data recorded in the .rw2 raw file > suffucient for lens correction? The RAW converters that use Lensfun (e.g. Darktable) cannot read the correction data embedded into the RAW file. Neither can Lensfun itself. > Following http://syscall.eu and applying the data extracted from an image of > mine, > I get, e.g., for an image with focal="9.1" > > scale = 1.0/(1.0+(data[5]/32768.0)); 1.0 > a = data[8]/32768.0; 0.19561767578125 > b = data[4]/32768.0; 0.145965576171875 > c = data[11]/32768.0; -0.14434814453125 > > Ru = scale*(Rd + a*Rd^3 + b*Rd^5 + c*Rd^7) > > How are these releated to the parameters for focal 9.1 above? I am aware of this reverse engineering, but I haven't had time to investigate this yet. > In this case the image processed by Silkypix differs significantly > from that produced by darktable which uses lensfun. If I crop the > image produced by darktable to pixels 173 .. 5299 x 115 .. 3533 > and rescale the image to 5472 x 3648 pixels I get a very similar > result to that produced by Silkypix. So, only the scaling was different? Tschö, Torsten. -- Torsten Bronger Jabber ID: [email protected] ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140 _______________________________________________ Lensfun-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/lensfun-users
