Venky009's profile - activity

cool..thanx for feedback..i wont repeat it again

if it is pure green ..how to do that without for loop pixel accessing ..is there anyway..@berak..i just want to know that logic

its ok bro..but how to access the pixel without for loop

load the img into mat ..read the r g b s pixel wise ..and use the condition if (r == 0 && g == 255 && b == 0) to make that pixel to 0..You can change the logic according to ur img intensities.

{;

cv::Mat img = cv::imread("inputPath");//3channel imagepath;

byte* img_ptr = (byte*)img.data;
int r, g, b;
for (int y = 0; y < img.rows; y++)
{
    for (int x = 0; x < img.cols; x++)
    {
        r = img_ptr[x * 3 + 2 + y*img.cols * 3];
        g = img_ptr[x * 3 + 1 + y*img.cols * 3];
        b = img_ptr[x * 3 + 0 + y*img.cols * 3];

        if (r == 0 && g == 255 && b == 0)
        {
            img_ptr[x * 3 + 2 + y*img.cols * 3]=0;
            img_ptr[x * 3 + 1 + y*img.cols * 3]=0;
            img_ptr[x * 3 + 0 + y*img.cols * 3]=0;
        }
    }
}
cv::imwrite("outputPath", img);
img.release();

}

Is it necessary to use opencv here .Because loading of mats ,,calling libs may slags the time.. cant we do these operations on frames without opencv..?

if resolution is not main concern u can resize the every frame to small and do rotate-flip then resize back the frame to its desired size..This rotate-flip on small image may saves time.we can use affine transform also for orientations

Found that ..clahe algo is expecting max value of 4096 instead of (2 power of 16=65535).. Max value in my input =65535 So i stretched the input image from 65535 to 4096..Got good result instead of over saturated pixels..but didnt see contrast enhancement in output..need to work on it.. used web link github

Thanks for feedback.

cv::Mat srcImage_3channels = cv::imread(InputPath, CV_LOAD_IMAGE_UNCHANGED);

    std::vector<cv::Mat> channels;
    cv::split(srcImage_3channels, channels);
    test::cvClahe(channels[0], channels[0], clipLimit);
    cv::imwrite(OutputPath, channels[0]);

    srcImage_3channels.release();
    srcImage.release();


            here used clipLimit=5;

Tried as u suggest ,but got same result as earlier one

@berak. srcImage is single channel image..plz see its declaration

I verified all imgs loadings ,savings and intensities using pixel access..all are gone well

I am seeing random and strange intensities in the output..they look like over saturated and under saturated.. I stretched this 16 bit input img to 8 bit ,then applied the clahe on this 8 bit..i got the expected result..(this is for verification)

I used mat in opencv cpp code to load images

Here is my code:

cv::Mat srcImage_3channels = cv::imread(InputPath, CV_LOAD_IMAGE_UNCHANGED);
    cv::Mat srcImage = cv::Mat::zeros(srcImage_3channels.rows, srcImage_3channels.cols, CV_16UC1);

    UINT16* src_3 = (UINT16*)srcImage_3channels.data;
    UINT16* src = (UINT16*)srcImage.data;

    int B = 0;

    for (int j = 0; j < srcImage_3channels.rows; j++)
    {
        for (int i = 0; i < srcImage_3channels.cols; i ++)
        {

            B = src_3[i*3 + j*srcImage_3channels.cols * 3];

            src[(i)+j*srcImage.cols] = (UINT16)B;//getting single channel from 3 channel image
        }

    }

    test::cvClahe(srcImage, srcImage, clipLimit);
            cv::imwrite(OutputPath, srcImage);

Hi,

Java language,Android platform:- I came to know that arraylist operations are slower than array.Please see the attched screenshot.Where I added the no of elements each by one by incrementing the index .

performed operatins for test :array.set(index,value),arrayList.set(index,value)

Where time is measured for adding all no.of elements.

could you suggest me any alternative is for arrayList other than array to save the time.

Condition:I dont know the no of elements to be added to array list , it is dynamic.

Sorry for my bad explanation..

Thanks in advance, Venky