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Questions tagged [image-processing]

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Is there a difference between training with multiple objects in a single image and multiple objects in a different images?

I'm trying to generate data for my object detection network (which will be used for TensorFlow: ResNet). What I'm currently curious about is this: if I have the same total amount of data (each data ...
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15 views

How can i compare lossy image compression techniques?

I need to find which lossy image compression technique is the best. I chose to test JPEG, WebP and BPG. Which criteria can I choose for comparison apart from quality and speed of compression and how ...
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9 views

Deep Learning Technique for Image to Video Conversion

I'm trying to build an engine for the following task: I have n videos, from which I've taken 1 snapshot each. I am trying to train a classification algorithm on these n snapshots. Till now I have ...
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10 views

Image quantization for grayscale images with alpha channel

I am looking for algorithm that quantize grayscale image that contains alpha to 4-bits (16 colors). I quite like the effect that is used in IrfanView to decrease color depth, however, I dont know the ...
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1answer
31 views

Fitting a polynomial to a set of points or to a skeleton

Available data Available to me is a set of points which can be represented as shown in image 1: Also available to me is a non-continuous path derived from this data. It is not important how this non-...
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37 views

Do image artefacts reveal the original image orientation?

An image is taken and then rotated by an arbitrary angle and cropped. Let us assume that the original image is rather meaningless and is not aligned in any way. Given the rotated image, is it ...
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8 views

Calculating spatial “orderedness” at each position in a binary image: entropy? lacunarity?

Let's say I have image where all pixel values are either 0 or 1. What I'd like to do is to be able to generate a new image with the same dimensions where each pixel represents how "ordered" the area ...
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20 views

How are image processing and computer vision related to artificial intelligence.?

We have often heard both terms image processing and computer vision in AI sessions But i am confused, how they both are related to artificial intelligence?
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1answer
69 views

Minimum Bounding Quadrilateral

In an image processing project (using opencv with python), I am trying to detect as precisely as possible the location of a rectangular object in a photograph. My final goal is to output the 4 corners ...
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34 views

Modifying the JPEG compression to use custom block patterns

recently, while watching a video about machine learning, I had an idea about creating an image compression algorithm, that works similar to JPEG, but is based on arbitrary bitmaps as blocks. I should ...
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Does the illumination color (red/blue/green) has any effect over the disparity map generated from a stereo image?

I have a working model that creates a disparity map using stereoscopic image processing using opencv. I am thinking of improving the disparity map by using illumination and stuck with different ...
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1answer
28 views

How to jump directly from level 0 to level 5 in a Gaussian pyramid without having the levels 1, 2, 3, and 4?

I am current studying the Laplacian Pyramid as a compact image code by Peter J Burt and Edawrd Hudson. I understood all the concepts but I am having trouble with the equivalent weighting function. I ...
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7 views

Constructing a 3D virtual map from 2D Depth Maps and $x, y, z, \theta$ coordinates

Context: I intend on building a quadrotor which can generate a 3D virtual map of an area of which it captures photos with a 2D camera. I plan on first training a Convulational NN to return a depth ...
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27 views

Training of two 3x3 convolution layers vs training one 5x5 convolution layer

I'm not 100% sure this is the right stackexchange, please feel free to redirect me to another one. I know that two 3x3 convolution layers can be equivalent to one 5x5 convolution layer. I also know ...
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19 views

Correct way to downsample a high-res image with jitter?

I'm new to image processing and I'm trying learn about image AA and upsampling algorithms such as those used in game engines. Engines tend to use jitter in order to get multiple samples from the same ...
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1answer
230 views

Efficient Algorithms for Destroyed Document Reconstruction

I am not certain this is the proper site for this question however I am mainly looking for resources on this topic (perhaps code). I was watching TV and one of the characters had a lawyer who ...
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21 views

How to do mathematical morphology manually? Erosion, dilation, open, close

How do you do mathematical morphology manually? If you have a kernel or structuring element B1 do you move the origin of B1 to every pixel in the matrix A1 and see if it is a perfect match, partial ...
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15 views

impact of the single pixel in disparity

Disparity essentially means the distance of a corresponding pixel in another image ( in pixels). This is clear and understood. When I looked after how the depth is related to disparity, then I found ...
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13 views

Similarity of images with tree shape drawn objects

I'm trying to find the best algorithm for my task. I have images looking like this one: I want to find the most similar ones from a set of such images. I tried several algorithms to compute the ...
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1answer
28 views

Image segmentation generates inclusions and is not smooth

I am performing segmentation using opencv, but the segmented image has regions with breaks and also the border isn't smooth. How can I handle this problems?
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1answer
715 views

How does a predictive coding aid in lossless compression?

I'm working on this lab where we need to apply a lossless predictive coding to an image before compressing it (with Huffman, or some other lossless compression algorithm). From the example seen ...
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1answer
29 views

Given two data feeds, find out if they capture the same information

Say, there are two camera feeds, how can I establish if they were filming the same scene? It seems plausible that there are algorithms that somehow calculate mutual information and detect "causality ...
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19 views

Maximum response filter

I am new to the field of Image processing. I recently came across MR8 filter and it is available in this link but I could not find well written expressions for mathematical treatment of the filter. ...
2
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1answer
124 views

Image convolution - image darkens

I'm using kernel convolution in python to blur an image, but in addition to blurring it also turns the image darker. Could someone explain why it happens? ...
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1answer
44 views

what is meant by support of a filter?

what is meant by support of a filter in context of image processing? In the attached link of a short tutorial for detecting bar in an image by gabor filter,it is said that γ=1 helps in finding the ...
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42 views

Why is sparsity useful in dictionary learning?

What is the particular reason for which we use sparse matrix X in dictionary learning equation Y=DX where Y is the signal matrix, D is dictionary and X is the coefficient matrix?
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2answers
39 views

identify abrupt frame changes in a video

The frames of live streams or videos, in general, do not flow smoothly. A sports game would have multiple cameras recording the game and hence, there will be camera switches in the stream. I am ...
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1answer
50 views

what the mean and median filters with an n x n kernel (neighborhood) do to the grey-levels of the image? [closed]

sorry i haven't found a good title for these three questions i'm wondering if someone could give me explaination with proof (if possible ) of these three questions : Given a grey-level image stored ...
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10 views

Conventional triangularization approach in computer vision?

m new in learning image processing in openCV concepts ;can somebody help me to understand "Conventional triangularization approach " in computer vision ?
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1answer
31 views

How do we fix area of detectors in object detection?

I have gone through various articles on medium and also some from other sites trying to understand SSD. I am able to figure out most of the things from articles except this one. They always say that ...
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0answers
60 views

Transform Image Point to Azimuth and Elevation

I'm working on an object tracker where I need to report the azimuth and elevation of targets. Both values should be scaled from degrees to unsigned 32-bit integers. For now I can ignore lens ...
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0answers
49 views

How to find corresponding points between two photos when there's a repeated pattern?

Suppose that I have two photos, I1 and I2 and I want to find a set of corresponding points between the two photos to define a homography between them. There are many algorithms for this purpose, ...
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1answer
98 views

(OCR ) How to Recognise Handwritten fractional numbers using Neural networks

I want to be able to recognise handwritten math numbers using images of the numbers , i was able to do create a ANN model for recognising simple decimal numbers , but i have no idea on how to ...
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3answers
50 views

How to prove that the erosion of a convex set by a convex set will result in a convex set?

How to prove that given convex sets A and B, the erosion of A by B will result in C - a convex set, too? I was given this question as a test-preparation, and I think it shuold be a proof, but I don't ...
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1answer
37 views

Matching/finding mathematical plot images

I'm trying to come up with a method to match a given mathematical plot against a database of other plots. To make it more specific: plots are generated in R as PNG and might have different dimensions. ...
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0answers
22 views

Evolving zero level set in images

I'm trying to implement a simple image segmentation application that accepts an initial contour and evolves it to compute a refined contour in successive iterations. I'm taking some inspiration from ...
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1answer
52 views

Comparing variable image to static image

What are Levenshtein distance algorithms, but for images? I will have one static image (the target: what it should look like) and one variable image (actual: what the user has created) For example, ...
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1answer
71 views

Data structures that store efficiently detected features of an image

I struggle to find this, suppose I apply any feature detection algorithm. From my references it seems to me it's not usually explained what kind of data structures would be suitable for storing such ...
2
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1answer
46 views

The task of recognizing game units in the screenshot

I'm new to computer vision and I want to solve the task of recognizing the game units of the game Clash Royale in the screenshot. Briefly, there are about 70 different types of gaming units belonging ...
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1answer
62 views

Sample K representative frames within a video

I have an image-based processing module that takes photos for some computer vision processing. I have many videos, but I need to sample representative frames as its inputs, preferably those frames ...
1
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1answer
69 views

calculting distance between a person and the object in the image

Let's say a person took an image like this I have access to all image attributes (like for example image format, resolution and so on), and I know the location of the person - basically the place ...
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0answers
20 views

Multiphase levelset Chan Vese algorithm

I am implementing the multiphase level Chan Vese algorithm. I am using IPOL document as reference (http://www.ipol.im/pub/art/2012/g-cv/article.pdf) Everything is clear for me, except the stopping ...
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1answer
2k views

What is the difference between luma and luminance?

I understand the following (correct me if I'm wrong): Statements Luma as the weighted sum of RGB gamma corrected components, but luminance is the weighted sum of RGB linear components. The gamma ...
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346 views

Backward mapping with bilinear sampler

I have some experiences with Convolutional Neural Networks before. I have a question regarding the Bilinear Sampler used in "Unsupervised Monocular Depth Estimation With Left-Right Consistency" (the ...
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290 views

How to recognize digits in water meter image

I need to read the digits of images like the one below: From what I understand, this will involve: Registering and segmenting the image into each individual digit Hand labeling a bunch of these ...
4
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1answer
83 views

Interpreting camera matrix

I'm having some trouble interpreting the camera matrix $K = \begin{bmatrix} f_x & s & x_0 \\ 0 & f_y & y_0 \\ 0 & 0 & 1 \end{bmatrix}$ after it multiplies some 3D vector. ...
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48 views

3-SAT reduction to image matching problem

I have a research paper, Elastic image matching is NP-complete by Daniel Keysers and Walter Unger, that illustrates the reduction from 3-SAT to an image matching problem in order to prove that this ...
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0answers
28 views

Accept something with probability

I am reading the following paper https://pdfs.semanticscholar.org/5e86/db52119d2d691af0365cdba7bb27dc0dc303.pdf and trying to implement the tabu search algorithm they describe for image segmentation. ...
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0answers
20 views

How to find the matched SIFT features that are spatially consistent?

I have extracted DenseSIFT from the query and database image and quantized by kmeans. The challenge is to find those SIFT features that quantized to the same visual ...
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32 views

Open source implementation of Multiscale Combinatorial Grouping [closed]

I would like to use Multiscale Combinatorial Grouping for my PhD research. However, I am restricted to use open-source implementations and this one runs on Matlab. Does anyone know of an equivalent ...