geopackage-sdk/src/main/java/mil/nga/geopackage/extension/coverage/CoverageDataTiff.java
public float getPixelValue(byte[] imageBytes, int x, int y) {

        TIFFImage tiffImage = TiffReader.readTiff(imageBytes);
        FileDirectory directory = tiffImage.getFileDirectory();
        validateImageType(directory);
        Rasters rasters = directory.readRasters();
        float pixelValue = rasters.getFirstPixelSample(x, y).floatValue();

        return pixelValue;
    }
public float getPixelValue(byte[] imageBytes, int x, int y) {

        TIFFImage tiffImage = TiffReader.readTiff(imageBytes);
        FileDirectory directory = tiffImage.getFileDirectory();
        validateImageType(directory);
        Rasters rasters = directory.readRasters();
        float pixelValue = rasters.getFirstPixelSample(x, y).floatValue();

        return pixelValue;
    }
Get the pixel value as a float from the image and the coordinate

@param imageBytes image bytes
@param x          x coordinate
@param y          y coordinate
@return float pixel value