extract flower buds in x-ray image

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I am trying to extract and count the number of buds in of a flower in an x-ray image. in the example images it is so obvious where the buds are and how many buds there are, but I can not get the buds separated enough for proper counting. It is no problem if I get some false hits on the stem, because we plan to feed the cropped buds into a NN for classification

original 8 bit image

the result I get is

The perfect result would be the below image, this is impossible i know, but it should be better than the above result

You can tweak this image by changing the threshold but then for the other images the result gets far worse.

8 bit enhanged images

16 bit original detector images

used code to get to current result.

// read first sample image
cv::Mat img8 = cv::imread("img8/006-img8bit.tif", cv::IMREAD_UNCHANGED);

// do some blur to remove most of the noise
cv::Mat imBlur;
cv::blur(img8, imBlur, cv::Size(5, 5));

// do close on grey image
cv::Mat imClose;
cv::Mat element = cv::getStructuringElement(cv::MORPH_ELLIPSE, cv::Size(15, 15));
cv::morphologyEx(imBlur, imClose, cv::MORPH_CLOSE, element);

// threshold image met auto threshold t.o.v. achtergrond kleur.
cv::Mat imgThresh;
//cv::adaptiveThreshold(imClose, imgThresh, 255, cv::ADAPTIVE_THRESH_MEAN_C, cv::THRESH_BINARY, 71, 15.0);
cv::threshold(imClose, imgThresh, 29, 255, cv::THRESH_BINARY);  // automatic thresholding

// fillup small holes in threshold image
element = cv::getStructuringElement(cv::MORPH_ELLIPSE, cv::Size(5, 5));
cv::Mat imThClosed;
cv::morphologyEx(imgThresh, imThClosed, cv::MORPH_CLOSE, element, cv::Point(-1, -1), 2);

// try to remove most stems from image
cv::Mat imgThClean;
element = cv::getStructuringElement(cv::MORPH_ELLIPSE, cv::Size(23, 23));
//cv::erode(imThClosed, imgThClean, element);
cv::morphologyEx(imThClosed, imgThClean, cv::MORPH_OPEN, element, cv::Point(-1, -1), 2);

// make contours
std::vector<std::vector<cv::Point> > contours;
cv::findContours(imgThClean.clone(), contours, cv::RETR_EXTERNAL, cv::CHAIN_APPROX_SIMPLE);

// draw the contours
cv::drawContours(img8, contours, -1, cv::Scalar(255));