用jfreechart生成心电图
先上成功的图片
上代码
1.导入包
implementation 'org.jfree:jfreechart:1.5.4'
implementation 'org.jfree:jcommon:1.0.24'
2.实现代码
对数据进行滤波
转换单位
package com.shinrun.infrastructure.util;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
public class ECGDataConverter {
/**
* 将原始数据转换为mV单位的数据
* @param rawData 原始数据数组
* @param scaleFactor 比例因子(20000对应1mV)
* @return 转换后的数据数组(单位mV)
*/
public static double[] convertToMillivolts(double[] rawData, double scaleFactor) {
double[] convertedData = new double[rawData.length];
for (int i = 0; i < rawData.length; i++) {
convertedData[i] = rawData[i] / scaleFactor;
}
return convertedData;
}
/**
* 将原始数据转换为微伏(uV)单位的数据
* @param rawData 原始数据数组
* @param scaleFactor 比例因子(20000对应1mV)
* @return 转换后的数据数组(单位uV)
*/
public static double[] convertToMicrovolts(double[] rawData, double scaleFactor) {
double[] convertedData = new double[rawData.length];
for (int i = 0; i < rawData.length; i++) {
convertedData[i] = (rawData[i] / scaleFactor) * 1000; // 转换为uV
}
return convertedData;
}
/**
* 移动平均滤波器 - 平滑高频噪声
* @param data 原始ECG数据(uV)
* @param windowSize 窗口大小(建议3-7)
* @return 滤波后的数据
*/
public static double[] movingAverageFilter(double[] data, int windowSize) {
if (windowSize < 1 || windowSize > data.length) {
throw new IllegalArgumentException("Invalid window size");
}
double[] filtered = new double[data.length];
int halfWindow = windowSize / 2;
for (int i = 0; i < data.length; i++) {
int start = Math.max(0, i - halfWindow);
int end = Math.min(data.length - 1, i + halfWindow);
double sum = 0;
int count = 0;
for (int j = start; j <= end; j++) {
sum += data[j];
count++;
}
filtered[i] = sum / count;
}
return filtered;
}
/**
* 中值滤波器 - 有效去除脉冲噪声
* @param data 原始ECG数据(uV)
* @param windowSize 窗口大小(建议3-5)
* @return 滤波后的数据
*/
public static double[] medianFilter(double[] data, int windowSize) {
if (windowSize < 1 || windowSize > data.length || windowSize % 2 == 0) {
throw new IllegalArgumentException("Window size must be odd and positive");
}
double[] filtered = new double[data.length];
int halfWindow = windowSize / 2;
double[] window = new double[windowSize];
for (int i = 0; i < data.length; i++) {
int start = Math.max(0, i - halfWindow);
int end = Math.min(data.length - 1, i + halfWindow);
// 填充窗口
int index = 0;
for (int j = start; j <= end; j++) {
window[index++] = data[j];
}
// 对窗口数据进行排序
Arrays.sort(window, 0, index);
// 取中值
filtered[i] = window[index / 2];
}
return filtered;
}
/**
* 基于阈值的异常值过滤
* @param data 原始ECG数据(uV)
* @param thresholdMultiplier 阈值乘数(建议2.5-3.5)
* @return 过滤后的数据
*/
public static double[] thresholdFilter(double[] data, double thresholdMultiplier) {
// 计算数据的均值和标准差
double mean = 0;
for (double v : data) {
mean += v;
}
mean /= data.length;
double stdDev = 0;
for (double v : data) {
stdDev += Math.pow(v - mean, 2);
}
stdDev = Math.sqrt(stdDev / data.length);
double threshold = thresholdMultiplier * stdDev;
double[] filtered = new double[data.length];
for (int i = 0; i < data.length; i++) {
if (Math.abs(data[i] - mean) > threshold) {
// 如果是异常值，用前后值的平均值替代
double prev = i > 0 ? filtered[i-1] : mean;
double next = i < data.length-1 ? data[i+1] : mean;
filtered[i] = (prev + next) / 2;
} else {
filtered[i] = data[i];
}
}
return filtered;
}
/**
* 组合滤波器 - 先中值滤波再移动平均
* @param data 原始ECG数据(uV)
* @param medianWindow 中值滤波窗口大小(建议3)
* @param averageWindow 移动平均窗口大小(建议5)
* @return 滤波后的数据
*/
public static double[] combinedFilter(double[] data, int medianWindow, int averageWindow) {
double[] medianFiltered = medianFilter(data, medianWindow);
return movingAverageFilter(medianFiltered, averageWindow);
}
/**
* 原始数据强过滤（处理ADC值）
* @param rawData 原始ADC数据
* @param maxAllowed 允许的最大ADC绝对值
* @return 过滤后的原始ADC数据
*/
public static double[] filterRawData(double[] rawData, double maxAllowed) {
if (rawData == null) {
return new double[0];
}
double[] filtered = Arrays.copyOf(rawData, rawData.length);
int windowSize = 7; // 使用前后各3个点（共7点窗口）
for (int i = 0; i < filtered.length; i++) {
if (Math.abs(filtered[i]) > maxAllowed) {
// 获取周围正常值的滑动窗口中值
filtered[i] = getSlidingWindowReplacement(filtered, i, windowSize, maxAllowed);
}
}
return filtered;
}
private static double getSlidingWindowReplacement(double[] data, int centerIdx,
int windowSize, double maxAllowed) {
int halfWindow = windowSize / 2;
List<Double> validValues = new ArrayList<>();
// 收集窗口内有效值
for (int i = -halfWindow; i <= halfWindow; i++) {
int actualIdx = centerIdx + i;
if (actualIdx >= 0 && actualIdx < data.length &&
Math.abs(data[actualIdx]) <= maxAllowed) {
validValues.add(data[actualIdx]);
}
}
// 处理策略（按优先级）：
if (!validValues.isEmpty()) {
// 1. 有有效值则取中位数
Collections.sort(validValues);
return validValues.get(validValues.size() / 2);
} else {
// 2. 无有效值则取前一个正常值（向前搜索）
for (int i = centerIdx - 1; i >= 0; i--) {
if (Math.abs(data[i]) <= maxAllowed) {
return data[i];
}
}
// 3. 极端情况返回0
return 0.0;
}
}
}
图片生成 方法
package com.shinrun.infrastructure.util;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartUtils;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.NumberAxis;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.renderer.xy.XYLineAndShapeRenderer;
import org.jfree.chart.ui.RectangleInsets;
import org.jfree.data.xy.XYSeries;
import org.jfree.data.xy.XYSeriesCollection;
import java.awt.*;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Base64;
/**
* 医疗级心电图生成工具类（10段垂直排列）
* 实现了标准心电图纸网格和比例尺
*/
public class ECGChartGenerator {
// ============= 默认参数配置 =============
private static final int DEFAULT_SAMPLE_RATE = 500; // 默认采样率500Hz
private static final int SEGMENT_COUNT = 10; // 固定10段心电图
private static final int DEFAULT_WIDTH = 800; // 图片默认宽度
private static final int SEGMENT_HEIGHT = 150; // 每段心电图高度
private static final int TOTAL_HEIGHT = SEGMENT_COUNT * SEGMENT_HEIGHT; // 总高度
// 心电图纸网格参数（医疗标准）
private static final int SMALL_GRID_MM = 1; // 小方格1mm
private static final int LARGE_GRID_MM = 5; // 大方格5mm(5个小方格)
private static final int GRID_SIZE_PX = 12; // 1mm对应的像素数(方法二)
// 心电图显示参数
private static final double DEFAULT_MM_PER_MV = 10.0; // 标准灵敏度:10mm/mV
private static final double DEFAULT_PAPER_SPEED_MM_PER_SEC = 25.0; // 标准走纸速度:25mm/s
private static final int DEFAULT_HEIGHT = 600; // 图片默认高度
/**
* 生成无标签的心电图纸网格
*/
public static String generateECGGrid() throws IOException {
// 创建空数据集（不需要实际数据）
XYSeriesCollection dataset = new XYSeriesCollection();
// 创建图表
JFreeChart chart = ChartFactory.createXYLineChart(
null, "", "", dataset);
// 自定义网格样式
customizeGridChart(chart);
return convertChartToBase64(chart, DEFAULT_WIDTH, DEFAULT_HEIGHT);
}
/**
* 自定义网格图表样式
*/
private static void customizeGridChart(JFreeChart chart) {
XYPlot plot = chart.getXYPlot();
// 1. 背景设置
plot.setBackgroundPaint(Color.WHITE);
chart.setBackgroundPaint(Color.WHITE);
// 2. 网格线设置(医疗标准)
plot.setDomainGridlinePaint(new Color(255, 200, 200)); // 小网格线颜色
plot.setRangeGridlinePaint(new Color(255, 200, 200));
plot.setDomainGridlineStroke(new BasicStroke(0.5f)); // 小网格线宽度
plot.setRangeGridlineStroke(new BasicStroke(0.5f));
// 计算网格大小(像素)
double smallGridPx = SMALL_GRID_MM * GRID_SIZE_PX;
double largeGridPx = LARGE_GRID_MM * GRID_SIZE_PX;
// 3. X轴(时间轴)设置 - 隐藏所有标签和刻度
NumberAxis xAxis = (NumberAxis) plot.getDomainAxis();
xAxis.setAxisLineVisible(false);
xAxis.setTickMarksVisible(false);
xAxis.setTickLabelsVisible(false);
xAxis.setStandardTickUnits(NumberAxis.createIntegerTickUnits());
xAxis.setTickUnit(new org.jfree.chart.axis.NumberTickUnit(largeGridPx));
// 4. Y轴(幅度轴)设置 - 隐藏所有标签和刻度
NumberAxis yAxis = (NumberAxis) plot.getRangeAxis();
yAxis.setAxisLineVisible(false);
yAxis.setTickMarksVisible(false);
yAxis.setTickLabelsVisible(false);
yAxis.setTickUnit(new org.jfree.chart.axis.NumberTickUnit(largeGridPx));
// 5. 移除所有渲染器（因为我们只需要网格）
plot.setRenderer(null);
// 6. 调整图表边距
plot.setAxisOffset(new RectangleInsets(5, 5, 5, 5));
// 7. 确保没有图例
chart.removeLegend();
// 8. 设置合适的范围以显示网格
xAxis.setRange(0, DEFAULT_WIDTH / GRID_SIZE_PX);
yAxis.setRange(0, DEFAULT_HEIGHT / GRID_SIZE_PX);
}
/**
* 使用默认参数生成10段ECG Base64图片
*/
public static String generateSegmentedECGImage(double[] ecgData) throws IOException {
return generateSegmentedECGImage(ecgData, DEFAULT_SAMPLE_RATE,
DEFAULT_MM_PER_MV, DEFAULT_PAPER_SPEED_MM_PER_SEC);
}
/**
* 自定义参数生成10段ECG Base64图片
*/
public static String generateSegmentedECGImage(double[] ecgData, int sampleRate,
double mmPerMv, double paperSpeedMmPerSec) throws IOException {
// 计算每段数据点数
int pointsPerSegment = ecgData.length / SEGMENT_COUNT;
XYSeriesCollection dataset = new XYSeriesCollection();
// 创建10个数据段
for (int seg = 0; seg < SEGMENT_COUNT; seg++) {
int start = seg * pointsPerSegment;
int end = (seg == SEGMENT_COUNT - 1) ? ecgData.length : start + pointsPerSegment;
XYSeries series = new XYSeries("ECG Segment " + (seg + 1));
// 垂直偏移量(使各段分开显示)
double yOffset = -seg * 2.0; // 每段下移2mV
for (int i = start; i < end; i++) {
// 计算时间并转换为毫米(基于走纸速度)
double timeSec = (i - start) / (double) sampleRate;
double xPosMm = timeSec * paperSpeedMmPerSec;
// 转换为像素
double xPixel = xPosMm * GRID_SIZE_PX;
// 转换ECG值到mV(输入是uV)
double valueMv = ecgData[i] / 1000.0;
// 应用垂直比例尺(mm/mV)
double yPosMm = valueMv * mmPerMv;
// 转换为像素并加上偏移量
double yPixel = yPosMm * GRID_SIZE_PX + (yOffset * mmPerMv * GRID_SIZE_PX);
series.add(xPixel, yPixel);
}
dataset.addSeries(series);
}
// 创建图表
JFreeChart chart = ChartFactory.createXYLineChart(
null, "时间 (mm)", "幅度 (mm)", dataset);
// 自定义心电图样式
customizeMedicalECGChart(chart, mmPerMv, paperSpeedMmPerSec);
return convertChartToBase64(chart, DEFAULT_WIDTH, TOTAL_HEIGHT);
}
/**
* 自定义心电图图表样式(医疗标准)
*/
private static void customizeMedicalECGChart(JFreeChart chart, double mmPerMv, double paperSpeedMmPerSec) {
XYPlot plot = chart.getXYPlot();
// 1. 背景设置
plot.setBackgroundPaint(Color.WHITE);
chart.setBackgroundPaint(Color.WHITE);
// 2. 网格线设置(医疗标准)
plot.setDomainGridlinePaint(new Color(255, 200, 200)); // 小网格线颜色
plot.setRangeGridlinePaint(new Color(255, 200, 200));
plot.setDomainGridlineStroke(new BasicStroke(0.5f)); // 小网格线宽度
plot.setRangeGridlineStroke(new BasicStroke(0.5f));
// 计算网格大小(像素)
double smallGridPx = SMALL_GRID_MM * GRID_SIZE_PX;
double largeGridPx = LARGE_GRID_MM * GRID_SIZE_PX;
// 3. X轴(时间轴)设置
NumberAxis xAxis = (NumberAxis) plot.getDomainAxis();
xAxis.setAxisLinePaint(Color.BLACK);
xAxis.setTickMarkPaint(Color.BLACK);
xAxis.setStandardTickUnits(NumberAxis.createIntegerTickUnits());
xAxis.setTickUnit(new org.jfree.chart.axis.NumberTickUnit(largeGridPx));
// 新版JFreeChart不再支持setMinorTickMarkPaint，改用以下方式设置次刻度
xAxis.setMinorTickCount(4);
xAxis.setMinorTickMarksVisible(true);
// 4. Y轴(幅度轴)设置
NumberAxis yAxis = (NumberAxis) plot.getRangeAxis();
yAxis.setAxisLinePaint(Color.BLACK);
yAxis.setTickMarkPaint(Color.BLACK);
yAxis.setTickUnit(new org.jfree.chart.axis.NumberTickUnit(largeGridPx));
yAxis.setMinorTickCount(4);
yAxis.setMinorTickMarksVisible(true);
// 5. 心电图曲线渲染设置
XYLineAndShapeRenderer renderer = new XYLineAndShapeRenderer();
renderer.setSeriesPaint(0, Color.BLACK);
renderer.setSeriesStroke(0, new BasicStroke(1.5f));
// 为所有段应用相同的渲染器
for (int i = 0; i < SEGMENT_COUNT; i++) {
plot.setRenderer(i, renderer);
renderer.setSeriesPaint(i, Color.BLACK);
renderer.setSeriesStroke(i, new BasicStroke(1.5f));
renderer.setSeriesShapesVisible(i, false);
}
// 6. 调整图表边距
plot.setAxisOffset(new RectangleInsets(5, 5, 5, 5));
// 7. 移除图例
chart.removeLegend();
// 8. 添加标题显示参数
chart.setTitle("心电图 - " + mmPerMv + "mm/mV, 走纸速度 " + paperSpeedMmPerSec + "mm/s");
}
/**
* 使用默认参数生成10段ECG Base64图片（无刻度值）
*/
public static String generateSegmentedECGImageNoLabels(double[] ecgData) throws IOException {
return generateSegmentedECGImageNoLabels(ecgData, DEFAULT_SAMPLE_RATE,
DEFAULT_MM_PER_MV, DEFAULT_PAPER_SPEED_MM_PER_SEC);
}
/**
* 自定义参数生成10段ECG Base64图片（无刻度值）
*/
public static String generateSegmentedECGImageNoLabels(double[] ecgData, int sampleRate,
double mmPerMv, double paperSpeedMmPerSec) throws IOException {
// 计算每段数据点数
int pointsPerSegment = ecgData.length / SEGMENT_COUNT;
XYSeriesCollection dataset = new XYSeriesCollection();
// 创建10个数据段
for (int seg = 0; seg < SEGMENT_COUNT; seg++) {
int start = seg * pointsPerSegment;
int end = (seg == SEGMENT_COUNT - 1) ? ecgData.length : start + pointsPerSegment;
XYSeries series = new XYSeries("ECG Segment " + (seg + 1));
// 垂直偏移量(使各段分开显示)
double yOffset = -seg * 2.0; // 每段下移2mV
for (int i = start; i < end; i++) {
// 计算时间并转换为毫米(基于走纸速度)
double timeSec = (i - start) / (double) sampleRate;
double xPosMm = timeSec * paperSpeedMmPerSec;
// 转换为像素
double xPixel = xPosMm * GRID_SIZE_PX;
// 转换ECG值到mV(输入是uV)
double valueMv = ecgData[i] / 1000.0;
// 应用垂直比例尺(mm/mV)
double yPosMm = valueMv * mmPerMv;
// 转换为像素并加上偏移量
double yPixel = yPosMm * GRID_SIZE_PX + (yOffset * mmPerMv * GRID_SIZE_PX);
series.add(xPixel, yPixel);
}
dataset.addSeries(series);
}
// 创建图表
JFreeChart chart = ChartFactory.createXYLineChart(
null, "", "", dataset); // 空标题和空轴标签
// 自定义心电图样式（无刻度值）
customizeMedicalECGChartNoLabels(chart, mmPerMv, paperSpeedMmPerSec);
return convertChartToBase64(chart, DEFAULT_WIDTH, TOTAL_HEIGHT);
}
/**
* 自定义心电图图表样式(医疗标准，无刻度值)
*/
private static void customizeMedicalECGChartNoLabels(JFreeChart chart, double mmPerMv, double paperSpeedMmPerSec) {
XYPlot plot = chart.getXYPlot();
// 1. 背景设置
plot.setBackgroundPaint(Color.WHITE);
chart.setBackgroundPaint(Color.WHITE);
// 2. 网格线设置(医疗标准)
plot.setDomainGridlinePaint(new Color(255, 200, 200)); // 小网格线颜色
plot.setRangeGridlinePaint(new Color(255, 200, 200));
plot.setDomainGridlineStroke(new BasicStroke(0.5f)); // 小网格线宽度
plot.setRangeGridlineStroke(new BasicStroke(0.5f));
// 计算网格大小(像素)
double smallGridPx = SMALL_GRID_MM * GRID_SIZE_PX;
double largeGridPx = LARGE_GRID_MM * GRID_SIZE_PX;
// 3. X轴(时间轴)设置 - 隐藏刻度值
NumberAxis xAxis = (NumberAxis) plot.getDomainAxis();
xAxis.setAxisLineVisible(false); // 隐藏轴线
xAxis.setTickMarksVisible(false); // 隐藏刻度线
xAxis.setTickLabelsVisible(false); // 隐藏刻度标签
xAxis.setStandardTickUnits(NumberAxis.createIntegerTickUnits());
xAxis.setTickUnit(new org.jfree.chart.axis.NumberTickUnit(largeGridPx));
// 4. Y轴(幅度轴)设置 - 隐藏刻度值
NumberAxis yAxis = (NumberAxis) plot.getRangeAxis();
yAxis.setAxisLineVisible(false); // 隐藏轴线
yAxis.setTickMarksVisible(false); // 隐藏刻度线
yAxis.setTickLabelsVisible(false); // 隐藏刻度标签
yAxis.setTickUnit(new org.jfree.chart.axis.NumberTickUnit(largeGridPx));
// 5. 心电图曲线渲染设置
XYLineAndShapeRenderer renderer = new XYLineAndShapeRenderer();
renderer.setSeriesPaint(0, Color.BLACK);
renderer.setSeriesStroke(0, new BasicStroke(0.8f));
// 为所有段应用相同的渲染器
for (int i = 0; i < SEGMENT_COUNT; i++) {
plot.setRenderer(i, renderer);
renderer.setSeriesPaint(i, Color.BLACK);
renderer.setSeriesStroke(i, new BasicStroke(0.8f));
renderer.setSeriesShapesVisible(i, false);
}
// 6. 调整图表边距
plot.setAxisOffset(new RectangleInsets(5, 5, 5, 5));
// 7. 移除图例
chart.removeLegend();
// 8. 移除标题
chart.setTitle("心电图 - " + mmPerMv + "mm/mV, 走纸速度 " + paperSpeedMmPerSec + "mm/s");
}
/**
* 将图表转换为Base64编码的PNG图片
*/
private static String convertChartToBase64(JFreeChart chart, int width, int height) throws IOException {
try (ByteArrayOutputStream outputStream = new ByteArrayOutputStream()) {
ChartUtils.writeChartAsPNG(outputStream, chart, width, height);
return "data:image/png;base64," +
Base64.getEncoder().encodeToString(outputStream.toByteArray());
}
}
}
讲解使用
我的心电图数据是来着于第三方平台的（是由机器将心电数据文件上传到第三方系统，第三方系统给我返回的double数组）
首先是进行 滤波，数据会有很大的外界因素影响，波动会很大，
再将数据转换成mv
再画图，进行调试
public String generateEcg(double[] rawData ) {
// 转换参数
double scaleFactor = 20.0;
String oss="";
// 方法1: 使用默认参数处理
double[] processedECG = ECGDataConverter.filterRawData(rawData,4000);
//转换成mv
double[] doubles = ECGDataConverter.convertToMillivolts(processedECG, scaleFactor);
// 生成时间轴
try {
String string = ECGChartGenerator.generateSegmentedECGImageNoLabels(doubles);
oss= uploadFile(string, "image/ecg");
} catch (IOException e) {
throw new RuntimeException(e);
}
return oss;
}
关键点
double[] processedECG = ECGDataConverter.filterRawData(rawData,4000);
这里 滤波参数我给的4000 其实就是 将超过4000的值给过滤掉，第三方给的数据 人的平均心跳峰值不超过4000，超过4000的那就不对需要过滤掉，这个根据你实际的数据进行修改
double scaleFactor = 20.0;
//转换成mv
double[] doubles = ECGDataConverter.convertToMillivolts(processedECG, scaleFactor);
这里传个参数scaleFactor ，其实就是对数据进行除一下，这里由于第三方给的数据不太规范，不除以一下的话画出来不太好看
一般数据除到是百位数就行了
如果上面两点没有做好的话效果可能如下
