fieldofview

The fieldofview function creates field of view image masks for fisheye images. Default field-of-view angles are derived from an illustration in the book “Beleuchtungstechnik Grundlagen“.

Usage:

mask = fieldofview(theta,rho,mode,theta_mask,rho_mask)

Where:

Parameter	Description
mask	Is the returned image mask.
theta	Is a matrix containing the polar rotation angles \vartheta in ° of the fisheye image.
rho	Is a matrix containing the tilt angles \rho in ° of the fisheye image.
mode	Defines the mask type: – 'left': left eye – 'right': right eye – 'binocular': both eyes – 'overlap': overlap of both eyes – 'user': user defined mask
theta_mask (optional)	Defines theta mask angles for 'user' mode.
rho_mask (optional)	Defines rho mask angles for 'user' mode.

Examples

Create left and right eye mask for LUMOS fisheye image:

% load hyperspectral LUMOS image
IM = readhyperspec('hyperspec.mat');
RGB = hyperspec2srgb(IM);

% create image masks
[theta, rho, omega] = fisheyeang;
left_eye = fieldofview(theta,rho,'left');
right_eye = fieldofview(theta,rho,'right');

% plot image with masks
figure(1)
imshow(RGB.*left_eye,[])
figure(2)
imshow(RGB.*right_eye,[])

See also: readhyperspec, hyperspec2srgb, fisheyeang

Result:

Create user specific field of view mask:

% load hyperspectral LUMOS image
IM = readhyperspec('hyperspec.mat');
MEL = hyperspec2unit(IM,'mel');

% create image mask
theta_mask = 0:90:360;
rho_mask = [90 90 90 60 90];
[theta,rho] = fisheyeang(500,180);
mask = fieldofview(theta,rho,'user',theta_mask,rho_mask);

% plot image mask
plotfalsecolours(mask.*MEL,'log','L_{e,mel} in W m^{-2} sr^{-1}')

See also: readhyperspec, hyperspec2unit, fisheyeang, plotfalsecolours

Result:

Reference for field of view angles:
Baehr, Barfuß and Seifert. “Beleuchtungstechnik Grundlagen”. 4th. edition. Ed.: LiTG. 2016. HUSS-MEDIEN GmbH, Verlag Technik. p.72. ISBN: 978-3-341-016343.

---