Questions tagged [filtering]
The filtering tag has no usage guidance.
16
questions with no upvoted or accepted answers
6
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OpenGL texelFetch causes black stripes
THE SHORT VERSION
In my fragment shader I'm reading (using texelFetch) multiple times the same texel from a texture (created by another fragment shader) and write it to the output render buffer. ...
- 313
2
votes
2
answers
232
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Properties of the image reconstruction filter in rendering
Let $f$ denote the measurement contribution function for paths of length $k\in\mathbb N$, i.e. $$f(x)=g(x_0\leftrightarrow x_1)W_{\text e}(x_1\to x_0)t_k(x_0,\ldots,x_k)L_{\text e}(x_k\to x_{k-1}),$$ ...
- 193
2
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0
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730
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how to overcome tracking jitter
I'm working with a object tracking project.
Steps:
Preprocessing the image and achieve some candidates regions of interest.
For each region, test if it is the target by ORB/BF.
After the target ...
- 121
2
votes
0
answers
145
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Image Laplacian incomprehension
I am reading and trying to implement a research paper.
It uses openGL to define which part of an image to use in order to reconstitute a big image composited of several images.
In order to do so, I ...
- 141
1
vote
0
answers
61
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What denoising filter gives highest quality for indirect light image?
Some background of my scenario: I have two images of indirect radiance, both are from an animation. I will reproject an pixel from the previous frame to current frame, and I want to do comparisons ...
- 51
1
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0
answers
455
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What is the difference between post-/pre- sampling, aliasing, filtering and processing?
What is the difference between post-/pre- sampling, aliasing, filtering and processing?
How do the terms post-/pre-aliasing, post-/pre-processing, post-/pre-sampling and post-/pre-filtering relate to ...
- 121
1
vote
0
answers
33
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Image contribution function and reconstruction using filters
So I've been reading Physicall Based Rendering which in section 16.4.3 defines the "image contribution function" to be the following
$$I_j = \int_\Omega h_j(X)L(X)d\Omega$$
where the variables are ...
- 205
1
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0
answers
68
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Why don't discretization errors occur with compute-shaded kernel filters?
An efficient compute-shaded image filter would be emitted with (screenX / [kernel width], screenY / [kernel height], 1) groups and one kernel in each group, allowing texels to pass into groupshared ...
- 447
1
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0
answers
1k
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YUV (NV12) Chroma subsampling while converting from RGB image
I convert RGB input to YUV 420 semi-planar output using compute shader.Luma plane is straightforward as it maps 1:1 with RGB dimensions. As we know, NV12 packs Cb and Cr into one plane, which means ...
- 259
1
vote
0
answers
107
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Why does this edge detect show different results for the same color combinations?
I'm researching highlighting accessible color contrast via filter operations. I have a test screenshot of SRGB hex values compared with WCAG's official contrast algorithm:
I converted it to its ...
- 111
1
vote
0
answers
52
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Removing a darkened caption with text on it in an image
Alright so I'm a complete n00b at image processing so forgive me if my question sounds vague. I'll try to supplement it with what I have learnt until now and also a couple of images.
See the caption ...
- 111
0
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0
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57
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How to retrieve RGBA mask used to transform image1 into image2
Let image1 be:
And RGBA mask be:
(45, 78, 251, 102)
Apply mask on top of ...
- 101
0
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0
answers
94
views
Relation between camera sensor responsivity and image reconstruction filter associated with a pixel
Let $W_{\text e}$ denote the camera sensor responsivity (i.e. importance) and $h_j$ and $W_{\text e}^{(j)}$ denote the image reconstruction filter and sensor response associated with the $j$th pixel, ...
- 193
0
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64
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Convolution of multiple gaussian filters with different sizes
What is the size of the final filter after implement convolution of multiple gaussian filters with different sizes?
0
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0
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547
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Lanczos filter implementation issue
I tried to follow Nathan Reed post Antialiasing: To Splat Or Not to implement splat method. The image I am getting thorugh the Lanczos filter is very different than Nathan. I do not understand where ...
- 710
0
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80
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Baked anisotropic filtering using spherical harmonics
I want to learn is it good or bad idea.
Let's assume video RAM is not a problem.
For source texture create a texture of texels: spherical functions. Spherical functions defined by small arrays of ...
- 241