Questions tagged [computer-vision]

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Is it possible to add new concept to ImageContents

I was hoping to use ImageContents to locate some specific objects in a series of images with a bounding box. However, ...
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2 votes
0 answers
125 views

Find the best place to overlay text on an image?

I need to put text over a background image to make a nice looking banner. In order to find the best place to put it, I'd like to know the "focus points" of the image (basically the centers ...
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5 votes
1 answer
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Noisy and vague shape recognition

Consider the following image: Imagine I have several images (let's say 40), that look like this one but with slightly different cloud shapes, pixel count intensities and distances between the clouds. ...
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Displacing / warping an image using a pre-existing optical flow image

ImageDisplacements provides a way to calculate the displacements between two images (e.g for optical flow purposes) and return a two channel image containing the dx,...
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2 votes
1 answer
138 views

Robust method to find vertical lines in image

Consider the following images with vertical grid lines. They can be loaded in mathematica by the following code: ...
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2 votes
0 answers
78 views

Detect pentagon in image

Problem: Given a UK Energy Performance Certificate (EPC) image, detect the pentagons containing integers between 1 and 100. (these are isosceles right pentagons) Example EPC image 1: ...
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1 vote
0 answers
37 views

ImageCorrespondingPoints[] using my own lists of unmatched points

ImageCorrespondingPoints[] finds a set of matching interest points in two images and returns their pixel coordinates. The doc says it "uses ...
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2 votes
0 answers
121 views

Shape-from-shading algorithms?

Before I go to the effort of writing my own code, I was wondering if there is code available for shape-from-shading algorithms. These take an image (such as a black-and-white image, such as this) and ...
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2 votes
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40 views

Faster alternative to ImageCorrespondingPoints?

I'm trying to use ImageCorrespondingPoints to register frames in a video sequence. Computational speed is an important consideration for the application I am ...
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4 votes
0 answers
206 views

Find nearest crop of image within another image

ImageAlign[ref, i] works well when image i is fully contained within the reference image ref,...
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1 vote
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ImageContents not working on Wolfram Cloud iOS app

I tried using the experimental ImageContents[] function, introduced in MMA 12, on my PC (using Mathematica) as well as on my iPad (using Wolfram Cloud app). On my ...
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  • 1,504
0 votes
1 answer
593 views

Best laptop specs for a better and faster numerical simulations [closed]

Hope all is well! I am planning to buy a laptop (Windows) and looking for your help to decide the specs that we need to speed up the numerical simulations using Mathematica. The Mathemtica code I used ...
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  • 313
8 votes
1 answer
263 views

How to detect rectangles with certain colors in an image?

I'd like to find the red bordered rectangles in this image: Here are my example images: ...
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4 votes
2 answers
276 views

Extract partitions of images after edge detection

Given a edge detected image like this: I would like to extract each character into a sub-image, i.e so that each new picture only have one character. Is there a simple way of doing this in ...
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6 votes
1 answer
223 views

How to track a deformable rod in video?

I have a video of nanotubes in solution taken with a confocal laser microscope. I typically track these nanotubes with Fiesta or Fiji, but in this case, there is variation in brightness that is ...
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0 votes
0 answers
127 views

Use FacialFeatures in Python Web API?

Under the hood, FacialFeatures uses the net-model ResNet-101 Trained on Augmented Casia WebFace Data. I would like to see a tutorial-style answer on how one would ...
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6 votes
0 answers
143 views

How to extend ImageCases?

I was very excited to see ImageCases being documented in version 12. But I immediately desired a mechanism for adding more entities to ...
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0 votes
1 answer
135 views

Robust face detection

FindFaces doesn't work when people are far away from the camera. I'm looking for a single accurate method of detecting one or more people in an images, at all ...
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10 votes
2 answers
241 views

Efficient multicolor search

I'm hoping someone can help me improve the following fun code-snippet, which takes a target color and searches through a set of images to find the ones that most closely match: ...
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16 votes
2 answers
764 views

How to TextRecognize a screenshot of code?

Are there any specific tricks or options to help TextRecognize work on a screenshot of an Input Cell or code in general? For example, here's a screenshot that ...
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3 votes
1 answer
273 views

Extract names from a document [closed]

If I have a document, any document, it can be a book, an article, etc, how could I extract people's names from there? For example, if the input is an article, the output of the function would be the ...
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3 votes
0 answers
196 views

Fourier image correlation is likely to be wrong [closed]

I have images of two identical ellipses, which differ by the orientation. I want to obtain the difference angle between them by means of phase corelation method (https://en.wikipedia.org/wiki/...
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1 vote
0 answers
120 views

Performance of ImageCorrelate with a masked kernel (via custom distance function)

Context For an image in-painting task (filling in missing regions in an image, see image below; missing region printed red) I'd like to try a template matching approach. The idea is to use parts of ...
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  • 8,259
3 votes
0 answers
570 views

Accessing advanced ZXing settings for BarcodeRecognize

Usual algorithms for detecting the presence of a QR-code in an image seem to have trouble detecting a code when it is tilted (especially at 45°). This is dependent on the resolution as well. The ...
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1 vote
2 answers
191 views

How to do the "Sketch colorization" like Project Scribbler using Mathematica? [closed]

Recently, the Adobe release the Project Scribbler Adobe Max 2017. The picture is from the P. Sangkloy, J. Lu, C. Fang, F. Yu and J. Hays. Scribbler: Controlling Deep Image Synthesis with Sketch and ...
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0 votes
1 answer
123 views

Removal Background with Shadows on HUE

I have an image of a leaf on a poorly white screen and need to find out just the leaf: The problem is that it contains greenish shadows, so simple color-based methods are not enough. Thus, I need ...
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4 votes
1 answer
159 views

Speeding up ImageCorrespondingPoints

I have the following problem: I am taking free-handedly photographs from the same scene during e.g. hiking, because sometimes I don't want to lug around a tripod. The goal is e.g. to create later on ...
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1 vote
0 answers
230 views

Rectangular object boundary detection

I would like to find the boundaries of an object: I have looked that the YOLO algorithm but it looks like the results cut off parts of the object a lot. What kind of algorithm can I use to achieve ...
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  • 111
1 vote
0 answers
476 views

Apply a four-point transform crop to an image

I am attempting to straighten and crop an image by using Edge Detection. The original image looks like this. By using edge detection and finding the max and min values for the points regarding the ...
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9 votes
1 answer
228 views

Adding computer vision datasets?

I find having ResourceData/Objects for machine learning datasets to be extremely useful, with their "TrainingData", "TestData" properties: Right now there's only a handful: And even fewer for ...
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  • 30.3k
46 votes
2 answers
8k views

Object detection and localization using neural network

Four important computer vision tasks are classification, localization, object detection and instance segmentation (image taken from cs224d course): These four tasks are all built on top of the deep ...
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2 votes
1 answer
468 views

How to import Robinhood screenshots?

I use an iPhone app called Robinhood to trade stocks and I wanted to play with the portfolio with Mathematica's finance tools. So I took some screenshots of the app and I'm trying to import the ...
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  • 30.3k
0 votes
0 answers
62 views

Improved version of FindFaces [duplicate]

The built-in function FindFaces seems to miss faces a lot, for example ...
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  • 30.3k
5 votes
1 answer
257 views

How to write a RCNN (region-cnn)?

Has anyone end-to-end trained a single net that can find the location of objects in an image (with v11.1)? Here's an example of a region-cnn in action, and this is a good description of the approach.
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5 votes
0 answers
468 views

How to train a visual attention model?

In version 11.1 there is a new layer type SequenceAttentionLayer[]. I'm interested in how might this be used to train a recurrent visual attention model (see the ...
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1 vote
2 answers
106 views

What is the algorithm applied by ImageAdjust[image,{c,b,gamma}]

I want to know how ImageAdjust work to change the pixel values by specifying all parameters b,c and gamma. In openCV, the transformation is linear ...
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6 votes
0 answers
545 views

How to recognize multiple objects in an image

I'm trying to do multi-object detection and recognition using Mathematica. For example, in this image: img = Import["https://i.stack.imgur.com/lbSwV.jpg"]; the ...
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  • 156
14 votes
3 answers
6k views

Nontrivial background removal

I have an image of a product on a poorly made green screen and need to segment out just the product: The problem is that it contains a mirror, so simple color-based methods are not enough. I tried ...
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  • 30.3k
18 votes
3 answers
1k views

Find lane lines

A crucial step in self-driving car is to detect lane lines. I'm wondering whether this can be achieved robustly using Mathematica's rich image processing tools. For example how can I take camera ...
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1 vote
0 answers
93 views

List of all valid categories for ImageIdentify? [closed]

Can anyone give me a list of valid categories for the second argument of ImageIdentify?
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  • 30.3k
16 votes
3 answers
1k views

How to place path lines on an image

I have a "sugarcane crop" image taken from above (with a Drone) which was pre-processed with the MorphologicalPerimeter and EdgeDetection functions of Mathematica, resulting in binary image with a ...
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  • 424
8 votes
2 answers
340 views

How to detect discolorations in an image?

I'm evaluating the technical quality of an images and I'd like to scan it for defects from dirty sensors. Are there any filters to quickly detect a blob of discoloration? Here are a few examples:
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24 votes
1 answer
1k views

How can I detect locations of Go (aka Baduk, Weiqi) stones on a board?

The Goal There are a couple apps that score a Go board from a photo. I was wondering if something like that would be possible with Mathematica. The key step is to detect the positions of the stones ...
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  • 1,113
2 votes
1 answer
425 views

How to get a full closed contour image [closed]

In this program, I need to select the point on the contour image that has the same abscissa as the center of the contour and has the highest ordinate. However, since the contour is not full closed, ...
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1 vote
0 answers
109 views

Using Classifier with NearestNeighbors methods

I am using a Machine learning toolbox on mathematica. I have 8 classes. Training data: for each class, there 100 samples with size 160. I used this code. ...
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4 votes
1 answer
1k views

How to label my training images?

I'm switching over Matlab, but I have a problem. Matlab has a GUI tool called the "Training Image Labeler" (shown below) that I use all the time to label my training data for my computer vision ...
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