add unit tests for LeptonicaFrameConverter#convert(Frame), see issue #…

…1115

src/test/java/LeptonicaFrameConverterTest.java

@@ -0,0 +1,130 @@
+import org.bytedeco.javacv.Frame;
+import org.bytedeco.javacv.LeptonicaFrameConverter;
+import org.bytedeco.javacv.OpenCVFrameConverter;
+import org.bytedeco.leptonica.PIX;
+import org.bytedeco.leptonica.global.leptonica;
+import org.bytedeco.opencv.global.opencv_imgcodecs;
+import org.bytedeco.opencv.opencv_core.Mat;
+import org.bytedeco.opencv.opencv_core.Point;
+import org.bytedeco.opencv.opencv_core.Scalar;
+import org.junit.jupiter.api.function.Executable;
+import org.junit.jupiter.api.io.CleanupMode;
+import org.junit.jupiter.api.io.TempDir;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+import static org.bytedeco.opencv.global.opencv_core.CV_8UC1;
+import static org.bytedeco.opencv.global.opencv_core.CV_8UC3;
+import static org.bytedeco.opencv.global.opencv_imgproc.line;
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+
+/**
+ * These tests compare that the Frame to Leptonica PIX converter works correctly against known-good
+ * files that come in different stride lengths.
+ *
+ * @link <a href="https://github.com/bytedeco/javacv/issues/1115">Source bug</a>
+ */
+public class LeptonicaFrameConverterTest {
+    @TempDir
+    static Path tempDir;
+
+    @ParameterizedTest
+    @ValueSource(ints = {8, 9, 10, 11, 12})
+    public void testBw(final int cols) {
+        LeptonicaFrameConverter lfcFixed = new LeptonicaFrameConverter();
+        OpenCVFrameConverter.ToMat matConverter = new OpenCVFrameConverter.ToMat();
+
+        final int rows = 10;
+
+        Mat originalImage = new Mat(rows, cols, CV_8UC1);
+        int stepX = 255 / cols;
+        int stepY = 255 / rows;
+        int stepTotal = Math.min(stepX, stepY);
+        for (int i = 0; i < originalImage.rows(); i++) {
+            for (int j = 0; j < originalImage.cols(); j++) {
+                line(originalImage, new Point(j, i), new Point(j, i), new Scalar(stepTotal * j));
+            }
+        }
+
+        //System.out.println(String.format("orig\n  capacity %d\n  w %d\n  h %d\n  ch %d\n  dpt %d\n  str %d", originalImage.asByteBuffer().capacity(), originalImage.cols(), originalImage.rows(), originalImage.channels(), originalImage.depth(), originalImage.step()));
+        opencv_imgcodecs.imwrite(tempDir + "/mat-bw-" + rows + "x" + cols + ".bmp", originalImage);
+        assertDoesNotThrow(new Executable() {
+            @Override
+            public void execute() throws Throwable {
+                assertArrayEquals(
+                        Files.readAllBytes(Paths.get(getClass().getClassLoader().getResource("LeptonicaFrameConverter/mat-bw-" + rows + "x" + cols + ".bmp").getPath())),
+                        Files.readAllBytes(Paths.get(tempDir + "/mat-bw-" + rows + "x" + cols + ".bmp")),
+                        "Mat file differs");
+            }
+        });
+
+        Frame ocrFrame = matConverter.convert(originalImage);
+        //System.out.println(String.format("frame\n  capacity %d\n  w %d\n  h %d\n  ch %d\n  dpt %d\n  str %d", ocrFrame.image[0].capacity(), ocrFrame.imageWidth, ocrFrame.imageHeight, ocrFrame.imageChannels, ocrFrame.imageDepth, ocrFrame.imageStride));
+
+        PIX converted = lfcFixed.convert(ocrFrame);
+        //System.out.println(String.format("fixconverted pix\n  capacity %d\n  w %d\n  h %d\n  ch %d\n  dpt %d\n  wpl %d", converted.createBuffer().capacity(), converted.w(), converted.h(), -1, converted.d(), converted.wpl()));
+        leptonica.pixWrite(tempDir + "/pix-bw-" + rows + "x" + cols + ".bmp", converted, leptonica.IFF_BMP);
+        assertDoesNotThrow(new Executable() {
+            @Override
+            public void execute() throws Throwable {
+                assertArrayEquals(
+                        Files.readAllBytes(Paths.get(getClass().getClassLoader().getResource("LeptonicaFrameConverter/pix-bw-" + rows + "x" + cols + ".bmp").getPath())),
+                        Files.readAllBytes(Paths.get(tempDir + "/pix-bw-" + rows + "x" + cols + ".bmp")),
+                        "Pix file differs");
+            }
+        });
+    }
+
+    @ParameterizedTest
+    @ValueSource(ints = {8, 9, 10, 11, 12})
+    public void testRgb(final int cols) {
+        LeptonicaFrameConverter lfcFixed = new LeptonicaFrameConverter();
+        OpenCVFrameConverter.ToMat matConverter = new OpenCVFrameConverter.ToMat();
+
+        final int rows = 10;
+
+        Mat originalImage = new Mat(rows, cols, CV_8UC3);
+        int stepX = 255 / cols;
+        int stepY = 255 / rows;
+        for (int i = 0; i < originalImage.rows(); i++) {
+            for (int j = 0; j < originalImage.cols(); j++) {
+                // Warning: OpenCV uses BGR ordering under the hood!
+                // See https://learnopencv.com/why-does-opencv-use-bgr-color-format/
+                line(originalImage, new Point(j, i), new Point(j, i), new Scalar(i * stepY, j * stepX, 0, 0));
+            }
+        }
+
+        //System.out.println(String.format("orig\n  capacity %d\n  w %d\n  h %d\n  ch %d\n  dpt %d\n  str %d", originalImage.asByteBuffer().capacity(), originalImage.cols(), originalImage.rows(), originalImage.channels(), originalImage.depth(), originalImage.step()));
+        opencv_imgcodecs.imwrite(tempDir + "/mat-rgb-" + rows + "x" + cols + ".bmp", originalImage);
+        assertDoesNotThrow(new Executable() {
+            @Override
+            public void execute() throws Throwable {
+                assertArrayEquals(
+                        Files.readAllBytes(Paths.get(getClass().getClassLoader().getResource("LeptonicaFrameConverter/mat-rgb-" + rows + "x" + cols + ".bmp").getPath())),
+                        Files.readAllBytes(Paths.get(tempDir + "/mat-rgb-" + rows + "x" + cols + ".bmp")),
+                        "Mat file differs");
+            }
+        });
+
+        Frame ocrFrame = matConverter.convert(originalImage);
+        //System.out.println(String.format("frame\n  capacity %d\n  w %d\n  h %d\n  ch %d\n  dpt %d\n  str %d", ocrFrame.image[0].capacity(), ocrFrame.imageWidth, ocrFrame.imageHeight, ocrFrame.imageChannels, ocrFrame.imageDepth, ocrFrame.imageStride));
+
+        PIX converted = lfcFixed.convert(ocrFrame);
+        //System.out.println(String.format("fixconverted pix\n  capacity %d\n  w %d\n  h %d\n  ch %d\n  dpt %d\n  wpl %d", converted.createBuffer().capacity(), converted.w(), converted.h(), -1, converted.d(), converted.wpl()));
+        leptonica.pixWrite(tempDir + "/pix-rgb-" + rows + "x" + cols + ".bmp", converted, leptonica.IFF_BMP);
+        assertDoesNotThrow(new Executable() {
+            @Override
+            public void execute() throws Throwable {
+                assertArrayEquals(
+                        Files.readAllBytes(Paths.get(getClass().getClassLoader().getResource("LeptonicaFrameConverter/pix-rgb-" + rows + "x" + cols + ".bmp").getPath())),
+                        Files.readAllBytes(Paths.get(tempDir + "/pix-rgb-" + rows + "x" + cols + ".bmp")),
+                        "Pix file differs");
+            }
+        });
+    }
+}