#
vcm

## Fisheye

the script call for Fisheye is

## vcm.Fisheye(clip[, int method = 3 ][, int xo = frame width / 2][,int yo = frame height / 2][, int frad = half of smaller of width and height][,int sqr = 1][,float rix = 1.2][,float fov = 120.0 ][,int q = 1][,int test = 0][,float dim = 0.25][, int dots = 2])

clip: input clip RGB, YUV444 or GRAY constant format.A plane if present is ignored.(may get rubbish)
method 1 to 5. 1. orthoganal, 2.linear , 3.equisolid 4.panoramic and 5 radial .
sqr: If not zero, the fisheye image if fully within input frame, the corrected image is fitted in superscribing square.
xo:X center coordinate of fish eye image.can be out of frame
yo:Y center coordinate of fish eye image. can be out of frame
frad: Radius of fish Eye image. Minimum 64. Make sure that at least part of fisheye image is in the input frame.
rix: Similar to refractive index. value be in range of 1.0 to 1.5.
fov: field of view. 40 to 170 degrees.
q: Type of interpolation. 1 to 4. 1. Manipal , 2. bilinear 2x2, 3. bicubic 4x4 and 4 lanczos 6X6. In test mode ignored.
test: If set to 1 a pattern of dots on dimmed input showing the area which will be used for transforming. If zero normal processing is carried out.
dim: input is dimmed by this factor to ensure the white dots are visible clearly on image. Used by test only.
dots: 1 to 4. Density of dots per some arbitrary square area.Used by test only.

Imaging by pin hole camera is almost without any distortion. Due to various reasons cameras with lens are used. The images produced will have distortions due to overall geometry and refractive indicies. Terms Barrel, pin cushion and fish eye are generally used for describing the distortions. In test mode effect of parameters used can be visualized for precise adjustments. The output frame size is changed suitably in methods 1 to 5 provided the Fish eye image is wholly within input frame. sqr works if the fisheye image is fully in input frame. As transforming fisheye image into normal image expands the size, usage of AddBorders may be required if part of fish eye image is outside input frame..

Circles function is an useful tool to specify radius.