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2015-04-16 13:34:39 -0600 asked a question I need help about the values psnr and mse obtained.

Best range of desirable values for PSNR and MSE. Guys, good night.

I am creating an application for similarity test between two images using PSNR and MSE, however, need to know how to interpret the values and whether these values are acceptable. For this, I need to understand how to interpret the data PSNR and MSE. How do I know what the best desirable value for PSNR and MSE?

3 processed images in my program and found the following values for PSNR and MSE:

Image 1 PSNR 11.87 MSE 4223.802679

Image 2 PSNR 26.02 MSE 162.57

Image 3 MSE PSNR 29.95 65.72

How do I interpret these values and know which track is desirable for a good similarity between images using the MSE and PSNR.

Thank you.
2015-04-16 07:57:16 -0600 commented question I need help about psnr and mse values obtained

I need help.
2015-04-16 07:56:17 -0600 commented answer I don't understand this values found in my results.

My image resolution is 8 bits. tomnjerry, do you think the values I found to PSNR and MSE are acceptable?
2015-04-15 21:22:34 -0600 asked a question I need help about psnr and mse values obtained

Best range of desirable values for PSNR and MSE. Guys, good night.

I am creating an application for similarity test between two images using PSNR and MSE, however, need to know how to interpret the values and whether these values are acceptable. For this, I need to understand how to interpret the data PSNR and MSE. How do I know what the best desirable value for PSNR and MSE?

3 processed images in my program and found the following values for PSNR and MSE:

Image 1 PSNR 11.87 MSE 4223.802679

Image 2 PSNR 26.02 MSE 162.57

Image 3 MSE PSNR 29.95 65.72

How do I interpret these values and know which track is desirable for a good similarity between images using the MSE and PSNR.

Thank you.
2015-04-15 10:59:03 -0600 commented answer I don't understand this values found in my results.

How to know what the best value found? How to know if the found values determine that the image has less noise and determining that they are similar? There is a range of minimum and maximum values for these metrics? Thank you.
2015-04-14 09:19:30 -0600 received badge ● Editor (source)
2015-04-14 09:18:09 -0600 asked a question I don't understand this values found in my results.

I processed two images for comparate and for obtained the PSNR and MSE values for generate results for my work of similarity between two images, but, i don't understand the generates results.

When i processing my images, i found the following results:

Image 1 PSNR 11.87 MSE 4223.802679

Image 2 PSNR 26.02 MSE 162.57

Image 3 PSNR 29.95 MSE 65.72

I need to understand the results. I don't understand the results. Thank you.
2015-03-27 12:24:38 -0600 asked a question What is a FlannBasedMatcher ?

I don't understand what is the FlannBasedMatcher ? Someone can explain me ?

Thanks!
2015-03-09 14:16:00 -0600 commented answer How to access multiple imagens in a vector of opencv

Thank you for help me!
2015-03-09 13:07:58 -0600 asked a question How to access multiple imagens in a vector of opencv

I need to add multiple images in an image in opencv vector. Can anyone explain me how to access each image in this vector. I need to learn this. Thank you.

2015-03-07 17:04:42 -0600 commented question How to copy a color image another coordinate mat.

I need copy my original image another different coordinate. For example, i want move my image for initial coordinate (30,30) another differente image. Help me!
2015-03-06 11:56:05 -0600 asked a question How to copy a color image another coordinate mat.

I want copy a color image another coodinate mate. I have to mats (src and dst) and need copy src for another coodinate in dst.

How i do this ?
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2015-02-28 15:12:46 -0600 commented answer How to create a vector of images in opencv ?

Sorry! I answer wrong. I need access the image of a vector. How to access ?
2015-02-28 15:06:43 -0600 commented answer How to create a vector of images in opencv ?

Steven how to access the elements of a vector ? Do you know ?
2015-02-28 14:42:49 -0600 asked a question How to create a vector of images in opencv ?

i need store various images in a vector using opencv ? How to make this ?

2015-02-21 13:22:11 -0600 commented question Doubt about how to access a pixel in cvMat structure

Thank you!
2015-02-21 13:21:20 -0600 received badge ● Enthusiast
2015-02-20 10:13:14 -0600 asked a question Doubt about how to access a pixel in cvMat structure

Hi,

How to access the value of pixel in structure cvMat ? I need access the pixels in a image with 3 channels. Can you help me ?

Thank you.
2015-02-09 20:50:25 -0600 asked a question How to discover my coordinate (0,0) after to apply warpperspective

Hi everyone,

How can i discover my coordinate (0,0) after to apply warpperspective in my image ? I want to come back for my original image.

Help me!

Thank you!
2015-02-09 17:04:49 -0600 commented question What units is the 'distance' measured in? (in the matches of a SURF)

What is the matches ? What is a diference between matches and keypoints ?

Thank you.
2015-02-09 16:32:03 -0600 answered a question What units is the 'distance' measured in? (in the matches of a SURF)

What is the matches ? What is a diference between matches and keypoints ?

Thank you.
2015-02-08 20:22:18 -0600 asked a question I don't understand a code about SURF (Mosaic)

Hy everyone,

I have a code for mosaic using SURF Transformer, but i don't understand some lines this code.

This is my code.

///////////////////////////////////////////

include <stdio.h>

include <iostream>

include "opencv2/core/core.hpp"

include "opencv2/features2d/features2d.hpp"

include "opencv2/highgui/highgui.hpp"

include "opencv2/nonfree/nonfree.hpp"

include "opencv2/calib3d/calib3d.hpp"

include "opencv2/imgproc/imgproc.hpp"

using namespace cv;

void readme();

/* @function main */ int main( int argc, char* argv ) {

// Load the images Mat image1= imread( "f.jpg"); Mat image2= imread( "e.jpg" ); Mat gray_image1; Mat gray_image2; // Convert to Grayscale cvtColor( image1, gray_image1, CV_RGB2GRAY ); cvtColor( image2, gray_image2, CV_RGB2GRAY );

imshow("first image",image2); imshow("second image",image1);

//-- Step 1: Detect the keypoints using SURF Detector int minHessian = 100;

SurfFeatureDetector detector( minHessian );

std::vector< KeyPoint > keypoints_object, keypoints_scene;

detector.detect( gray_image1, keypoints_object ); detector.detect( gray_image2, keypoints_scene );

//-- Step 2: Calculate descriptors (feature vectors) SurfDescriptorExtractor extractor;

Mat descriptors_object, descriptors_scene;

extractor.compute( gray_image1, keypoints_object, descriptors_object ); extractor.compute( gray_image2, keypoints_scene, descriptors_scene );

//-- Step 3: Matching descriptor vectors using FLANN matcher FlannBasedMatcher matcher; std::vector< DMatch > matches; matcher.match( descriptors_object, descriptors_scene, matches );

double max_dist = 0; double min_dist = 100;

//-- Quick calculation of max and min distances between keypoints for( int i = 0; i < descriptors_object.rows; i++ ) { double dist = matches[i].distance; if( dist < min_dist ) min_dist = dist; if( dist > max_dist ) max_dist = dist; }

printf("-- Max dist : %f \n", max_dist ); printf("-- Min dist : %f \n", min_dist );

//-- Use only "good" matches (i.e. whose distance is less than 3*min_dist ) std::vector< DMatch > good_matches;

for( int i = 0; i < descriptors_object.rows; i++ ) { if( matches[i].distance < 3*min_dist ) { good_matches.push_back( matches[i]); } } std::vector< Point2f > obj; std::vector< Point2f > scene;

for( int i = 0; i < good_matches.size(); i++ ) { //-- Get the keypoints from the good matches obj.push_back( keypoints_object[ good_matches[i].queryIdx ].pt ); scene.push_back( keypoints_scene[ good_matches[i].trainIdx ].pt ); }

// Find the Homography Matrix Mat H = findHomography( obj, scene, CV_RANSAC); // Use the Homography Matrix to warp the images cv::Mat result; warpPerspective(image1,result,H,cv::Size((image1.cols+image2.cols),(2*image1.rows))); imshow("WARP", result); cv::Mat half(result,cv::Rect(0,0,image2.cols,image2.rows)); image2.copyTo(half);

Mat key; //drawKeypoints(image1,keypoints_scene,key,Scalar::all(-1), DrawMatchesFlags::DEFAULT ); //drawMatches(image2, keypoints_scene, image1, keypoints_object, matches, result);

imshow( "Result", result ); //imshow("Key", key);

cv::Size s = result.size(); int rows = s.height; int cols = s.width;

printf("\n\nHeight: %d - Width: %d", rows, cols); imwrite("teste.jpg", result); waitKey(0); return 0; }

/** @function readme */ void readme() { std::cout << " Usage: Panorama < img1 > < img2 >" << std::endl; }

My doubts about this code is...

01) What is the matches ?

//-- Step 3: Matching descriptor vectors using FLANN matcher FlannBasedMatcher matcher; std::vector< DMatch > matches; matcher.match( descriptors_object, descriptors_scene, matches );

02) What is the max and min distance ?

//-- Quick calculation of max and min distances between keypoints for( int i = 0; i < descriptors_object.rows; i++ ) { double dist = matches[i].distance; if( dist < min_dist ) min_dist = dist; if( dist > max_dist ) max_dist = dist; }

03) When i apply a homography matrix in my image, my image is warp and my ... (more)
2015-02-05 08:11:30 -0600 asked a question What is a Hessian Parameter ?

I am with a doubt about a Hessian parameter used in SURF Transformer. I need help .

Thank you.
2015-02-05 07:52:45 -0600 commented answer Doubt about homography matrix

Hello,

Thank you for answer !
2015-02-04 12:24:18 -0600 received badge ● Student (source)
2015-02-04 12:04:31 -0600 commented answer Doubt about implementation of mosaic using SURF

Hi,

Thank you for answer my doubt. But, my problem is complicated...

I have this line in my code, but i want a new height of my image after a application of warp. I want to learn a new height and width after a application of warpperspective in my image. This is my problem.

Thank you.
2015-02-04 11:55:22 -0600 asked a question Doubt about homography matrix

Hi everyone,

I am working with mosaic for an application, but i don't understand about homography matrix. I need understand for develop my application. I need learn a basic about homography matrix. Can you help me ?

Than you, everyone!
2015-02-02 09:59:58 -0600 asked a question Doubt about implementation of mosaic using SURF

Hi everyone,

I am with a doubt about mosaic when i using SURF Transformer. I need apply SURF for make a mosaic, but, there is a problem. When i apply warp perspective, i need to know discover a new height of my image.

How to know a new height of my image, after of application of warp perspective ?

Thank you!

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