The original stereo pair was 3603x2736 pixels (provided by my good friend Mike). I chose to reduce it by 50% (for convenience) to end up with a stereo pair of size 1802x1368 pixels. First step is to rectify the images in order to end up with matching pixels on horizontal lines, a requirement for most automatic depth map generators. Here, I am using ER9b but it's probably ok to rectify/align with StereoPhoto Maker.
ER9b gives:
min disparity = -53
max disparity = 1
We are gonna use those as input to the automatic depth map generator. The min and max disparities may also be obtained manually with DF2.
We are gonna use DMAG5 (first using a large radius and then using a small radius) followed by DMAG9b to get the depth map. I could have used other automatic depth map generators but I kinda like DMAG5 because it's fast and usually pretty good.
Let's start by using a large radius (equal to 32). Parameters used in DMAG5 (Note that I use a downsampling factor equal to 2 instead of 1 to speed things up.):
radius = 32
alpha = 0.9
truncation (color) = 30
truncation (gradient) = 10
epsilon = 255^2*10^-4
disparity tolerance = 0
radius to smooth occlusions = 9
sigma_space = 9
sigma_color = 25.5
downsampling factor = 2
Let's follow up with DMAG9b to improve the depth map. Parameters used in DMAG9b:
sample_rate_spatial = 16
sample_rate_range = 8
lambda = 0.25
hash_table_size = 100000
nbr of iterations (linear solver) = 25
sigma_gm = 1
nbr of iterations (irls) = 32
radius (confidence map) = 12
gamma proximity (confidence map) = 12
gamma color similarity (confidence map) = 12
sigma (confidence map) = 4
It's time now to use a small radius in DMAG5 (equal to 4). Parameters used in DMAG5:
radius = 4
alpha = 0.9
truncation (color) = 30
truncation (gradient) = 10
epsilon = 255^2*10^-4
disparity tolerance = 0
radius to smooth occlusions = 9
sigma_space = 9
sigma_color = 25.5
downsampling factor = 2
Let's follow up with DMAG9b to improve the depth map. Parameters used in DMAG9b (same as before):
sample_rate_spatial = 16
sample_rate_range = 8
lambda = 0.25
hash_table_size = 100000
nbr of iterations (linear solver) = 25
sigma_gm = 1
nbr of iterations (irls) = 32
radius (confidence map) = 12
gamma proximity (confidence map) = 12
gamma color similarity (confidence map) = 12
sigma (confidence map) = 4
I am gonna go with the depth map obtained using the small radius. Is it the best depth map that could be obtained automatically? Probably not because one could have tweaked further the parameters used in DMAG5 and DMAG9b. Also, one could have tried using DMAG2, DMAG3, DMAG5b, DMAG5c, DMAG6, or DMAG7 instead of DMAG5 to get the initial depth map. That's a whole lot of variables to worry about. Anyways, now is time to generate synthetic frames with FSG4 using the left image and the left depth map (and going on either side).
Parameters used for FSG4:
stereo window (grayscale value) = 128
stereo effect = 5
number of frames = 12
radius = 2
gamma proximity = 12
maximum number iterations = 200
Inpainting is typically done by applying a Gaussian blur, which explains why inpainted areas look blurry. FSG6 produces synthetic frames of better quality because the right image and depth map are also used to inpaint. However, with FSG6, the synthetic frames are limited to be between the left and right images.
Now, if the object of the game was to create a lenticular, those synthetic views would be now fed to either SuperFlip or LIC (Lenticular Image Creator) to create an interlaced image. The fun would not stop here however as this interlaced image would have to be printed on paper and then glued to a lenticular lens. Yes, it is indeed a whole lot of work!
Automatic depth map generation, stereo matching, multi-view stereo, Structure from Motion (SfM), photogrammetry, 2d to 3d conversion, etc. Check the "3D Software" tab for my free 3d software. Turn photos into paintings like impasto oil paintings, cel shaded cartoons, or watercolors. Check the "Painting Software" tab for my image-based painting software. Problems running my software? Send me your input data and I will do it for you.
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what are the differences between right and left images
ReplyDeletethe left image was taken by left lens of a stereo camera and the right image by the right lens, so the point of view is slightly different.
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