#106 Add support for Canon PowerShot A1200

[junga]

Hello!
Here is the distortion calibration for the Canon PowerShot A1200.

[junga]

Please, add the same camera Canon PowerShot A1300.

[junga]

I apologize, found a typo in "b" for "focal = 9.06". Should be b="0.0528":

    <lens>
        <maker>Canon</maker>
        <model>Canon PowerShot A1200</model>
        <model lang="en">fixed lens</model>
        <mount>canonA1200</mount>
        <cropfactor>5.61</cropfactor>
        <aspect-ratio>4:3</aspect-ratio>
        <calibration>
            <distortion model="ptlens" focal="5" a="-0.00277" b="0.008202" c="-0.023857"/>
            <distortion model="ptlens" focal="6.36" a="0.024534" b="-0.098974" c="0.102683"/>
            <distortion model="ptlens" focal="7.41" a="0.017966" b="-0.069396" c="0.065749"/>
            <distortion model="ptlens" focal="9.06" a="-0.019176" b="0.0528" c="-0.062398"/>
            <distortion model="ptlens" focal="10.91" a="-0.014637" b="0.040343" c="-0.050821"/>
            <distortion model="ptlens" focal="13.05" a="-0.013019" b="0.031076" c="-0.034525"/>
            <distortion model="ptlens" focal="15.69" a="0.001945" b="-0.017517" c="0.020348"/>
            <distortion model="ptlens" focal="20" a="-0.011521" b="0.03586" c="-0.044143"/>
        </calibration>
    </lens>