5 votes

Removing Noise from Dental Radiography

As far as I understood, by image derivation you mean extracting edges. I would recommend to filter the image by a relatively large Gaussian filter. If computational cost of image derivation is ...
MimSaad's user avatar
  • 1,976
3 votes
Accepted

How to recognize speech bubbles in comic strips (Ideally OpenCV)

As said in the comments an efficient way is to first detect letters, words and text with OCR. Then try to expand each text zone to its corresponding text bubble. Depending on the text bubble design ...
Louis Lac's user avatar
  • 378
3 votes
Accepted

Multi-scale in Object detection?

Multiscale object detection generally consists in smoothing the image with larger and larger kernels, to check which objects persist across different scales. So, zoom-out, mostly. You now can have ...
Laurent Duval's user avatar
3 votes
Accepted

Algo Name: Detecting Elongated Shape in 2D Image by Convolution with Directed Lines

What you are essentially doing is a matched filter. However, thanks to Hough transform, your filter (line) is oriented and therefore I would call it an oriented matched filter. For generating the ...
Tolga Birdal's user avatar
  • 5,465
2 votes

Improving Template Matching Algorithm for OpenCV

I assume that the image have same scales in terms of sizes. With that out of the way, I would suggest try using the following: Break up your image into parts. (the template image as well as the test ...
Vinayak Daramwar's user avatar
2 votes

Algorithm for Scale Invariant Template Matching

Just wanted to give a little bit of modern answer to this question. In the 'machine learning' sense. Such matching problems are (maybe a little unfortunately) rebranded as one-shot object detection or ...
Tolga Birdal's user avatar
  • 5,465
1 vote

How to detect faint, dense grains on an image?

You want to segment the image into "grain" and "non-grain" areas. Then you want to label the "grain" areas. Segmentation is easy in principle: you process the image into ...
TimWescott's user avatar
  • 12.7k
1 vote
Accepted

Recognizing bees in a beehive

Optical Challenges I assume that to be hard, physically. At any given time, most bees in a hive are sisters – the sperm of the few drones that the queen mated with is gone through more or less in &...
Marcus Müller's user avatar
1 vote
Accepted

Video processing to detect a logo in frames

If you know where the logo is then you can detect its presence, fairly quickly, with cross-correlation...with a little bit more work. Detecting the presence of "things" using cross-correlation is a ...
A_A's user avatar
  • 10.7k
1 vote

Algorithm for Scale Invariant Template Matching

I believe Haar Cascades(used by Viola-Jones) are inherently scale-invariant. Also severely deprecated by modern Neural Networks, but I know nothing about those. It also doesn't do any OCR - if you ...
Vorac's user avatar
  • 233
1 vote
Accepted

Algorithm for Scale Invariant Template Matching

If your templates are all based on some kind of text you may use some kind of OCR to match the text itself and not only by features. Regarding features, you may read: A Comparative Analysis of SIFT, ...
Royi's user avatar
  • 19.6k
1 vote
Accepted

How to distinguish the same object entering the camera field of view

My solution would incorporate 3 different components: Detection. Recognition. Tracking. I'd train an object detector model (Look at YOLO 8 as a starting point) for detecting the insect. You could ...
Royi's user avatar
  • 19.6k
1 vote

Easiest Pattern to Recognize with Machine Vision

In case you can shoot a video of the static scene than a blinking light would be the easiest as you could easily detect it by subtracting the n - 1 frame from the <...
Royi's user avatar
  • 19.6k
1 vote

Detect non rectangular bounding box for objects

Let's label your corners like this: 1-------2 | | 3-------4 For your destination. Let, $P_1, P_2, P_3, \text{ and } P_4 $ be vectors representing the corners in pixel coordinates. For your ...
Cedron Dawg's user avatar
  • 7,560
1 vote
Accepted

Red Blood Cell Color Image Segmentation

Using Matlab: You might try converting your image to greyscale first with greycells = rgb2gray(rgbcells); where rgbcells contains the color image of your cells (...
geo's user avatar
  • 184
1 vote
Accepted

How to use optical character recognition program to read coins?

Without seeing the coins it's not easy to give a unique solution. A possibility would be: Use the Hough transform to detect circles (the coin). Then do some open/close operations to get blocks of text,...
Filipe Pinto's user avatar
1 vote

Pattern matching methods: Based on Area and Based on features

Yes, if applied properly, HOG is a good feature extractor even for OCR. I could point you towards an OpenCV sample and a MATLAB digit classification tutorial which do exactly that. However, if you ...
Tolga Birdal's user avatar
  • 5,465
1 vote

Is image processing impacted by the lens or sensor size of the camera?

Is image processing impacted by the lens or sensor size of the camera? Yes, since both affect the image that is processed. That was easy :) For the purposes of object detection and tracking, does ...
Marcus Müller's user avatar
1 vote
Accepted

Best reference for object size estimation in an image

The usual way to do this is to form a calibration plate. One way to form a calibration plate is to place known-shaped "fiducials" in a known-sized array on the surface where you want to do the ...
Peter K.'s user avatar
  • 25.7k
1 vote

How to find a noisy line in a picture

What about an algorithm in image domain? For every pixel, check into the direction you desire to know (up-down in your images above, I guess) if there is a pixel with "the same" value (i.e. a value ...
M529's user avatar
  • 1,736
1 vote

What is the ideal type of barcode for paper tickets?

PDF417 and Aztec code appear to be the most popular barcode symbologies for printed paper tickets and similar applications… PDF417 is used in many applications by both commercial and government ...
Dan Lenski's user avatar
1 vote

Object detection versus object recognition

late, but here is the answer. source: https://www.learnopencv.com/selective-search-for-object-detection-cpp-python/ An object recognition algorithm identifies which objects are present in an image. ...
Asif Mohammed's user avatar
1 vote

What is a good distance measure for matching SIFT descriptors depending on the distribution of their noise?

For obtaining distributions or modes in your, a basic approach is to cluster the data. That will of course bias the distribution towards the metric, or in other words the distribution will be tied to ...
Tolga Birdal's user avatar
  • 5,465
1 vote

Scale and Rotation invariant feature descriptors

If you remap a local patch around a feature point to log–polar coordinates (with the origin in the point of interest), scale changes correspond to a translation along the log–radial axis, while ...
HelloGoodbye's user avatar
1 vote

How to recognize an object from a small training set of images?

Few reasons i could think of are: Size of your training set is very small. Larger training sets have always been the key for accuracy. Each algorithm will have some drawback like SURF is not good at ...
Navin Prashath's user avatar
1 vote

Summed-area table vs Integral image?

The Sum-area table (SAT) was introduced in computer graphics, and as far as I know, was popularized in computer vision and image processing under the name Integral image. Apart from a larger ...
Laurent Duval's user avatar
1 vote

Can I use standard computer vision techniques for images taken in the NIR spectral range?

if it is possible to employ standard stereo matching algorithms like block-matching to images taken in the NIR spectrum and if so would it be possible (of course depending on the conditions) to obtain ...
A_A's user avatar
  • 10.7k
1 vote

Can I use standard computer vision techniques for images taken in the NIR spectral range?

I have a collection of 170 reflectance spectra of various "materials" (such as ripe brown banana and asphalt) attributed to Ron Gershon of Eastman Kodak. I believe they are diffuse reflectance, which ...
Olli Niemitalo's user avatar
1 vote

Can I use standard computer vision techniques for images taken in the NIR spectral range?

As far as I know, it is a common practice to use regular image processing techniques in this field. In fact I have recently finished a project in this field. if it is possible to employ standard ...
MimSaad's user avatar
  • 1,976
1 vote

Detecting objects in real world video feed?

There is no straight-forward answer to this. But I can tell you the things you need to consider to choose a method. Before getting into the methods to detect the object in the reference image, let me ...
harshkn's user avatar
  • 241

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