如何确定和自动旋转图像？

Question

我有一堆图像,其中一些图像必须旋转.

样品:

我想将此图像逆时针旋转90°.

我用Google搜索知道如何旋转图像并找到许多链接和SO线程.但是如何确定图像是否需要旋转？Picasa具有自动旋转功能.我想要有类似的功能.

任何指针都对我很有帮助.

我找到了一个链接,但它与Android有关.

Answer 1

的指针元数据提取器,其罗杰·罗兰提供解决了这个问题.我将其发布在此处以供将来参考:

import java.awt.geom.AffineTransform;
import java.awt.image.AffineTransformOp;
import java.awt.image.BufferedImage;
import java.io.File;

import javax.imageio.ImageIO;

import com.drew.imaging.ImageMetadataReader;
import com.drew.metadata.Metadata;
import com.drew.metadata.exif.ExifIFD0Directory;
import com.drew.metadata.jpeg.JpegDirectory;

public class Main {

    private static String inFilePath = "C:\\Users\\TapasB\\Desktop\\MHIS031522.jpg";
    private static String outFilePath = "C:\\Users\\TapasB\\Desktop\\MHIS031522-rotated.jpg";

    public static void main(String[] args) throws Exception {
        File imageFile = new File(inFilePath);
        BufferedImage originalImage = ImageIO.read(imageFile);

        Metadata metadata = ImageMetadataReader.readMetadata(imageFile);
        ExifIFD0Directory exifIFD0Directory = metadata.getDirectory(ExifIFD0Directory.class);
        JpegDirectory jpegDirectory = (JpegDirectory) metadata.getDirectory(JpegDirectory.class);

        int orientation = 1;
        try {
            orientation = exifIFD0Directory.getInt(ExifIFD0Directory.TAG_ORIENTATION);
        } catch (Exception ex) {
            ex.printStackTrace();
        }

        int width = jpegDirectory.getImageWidth();
        int height = jpegDirectory.getImageHeight();

        AffineTransform affineTransform = new AffineTransform();

        switch (orientation) {
        case 1:
            break;
        case 2: // Flip X
            affineTransform.scale(-1.0, 1.0);
            affineTransform.translate(-width, 0);
            break;
        case 3: // PI rotation
            affineTransform.translate(width, height);
            affineTransform.rotate(Math.PI);
            break;
        case 4: // Flip Y
            affineTransform.scale(1.0, -1.0);
            affineTransform.translate(0, -height);
            break;
        case 5: // - PI/2 and Flip X
            affineTransform.rotate(-Math.PI / 2);
            affineTransform.scale(-1.0, 1.0);
            break;
        case 6: // -PI/2 and -width
            affineTransform.translate(height, 0);
            affineTransform.rotate(Math.PI / 2);
            break;
        case 7: // PI/2 and Flip
            affineTransform.scale(-1.0, 1.0);
            affineTransform.translate(-height, 0);
            affineTransform.translate(0, width);
            affineTransform.rotate(3 * Math.PI / 2);
            break;
        case 8: // PI / 2
            affineTransform.translate(0, width);
            affineTransform.rotate(3 * Math.PI / 2);
            break;
        default:
            break;
        }       

        AffineTransformOp affineTransformOp = new AffineTransformOp(affineTransform, AffineTransformOp.TYPE_BILINEAR);  
        BufferedImage destinationImage = new BufferedImage(originalImage.getHeight(), originalImage.getWidth(), originalImage.getType());
        destinationImage = affineTransformOp.filter(originalImage, destinationImage);
        ImageIO.write(destinationImage, "jpg", new File(outFilePath));
    }
}

Answer 2

我有一些问题让一些开关案例起作用.即使没有旋转,AffineTransform也会在图像中创建一个带有黑色空间的新图像,并会切掉一些尺寸.小猪退出接受的答案,我使用元数据提取器类来确定方向应该是什么.然后我使用Imgscalr库进行缩放和旋转.

可以在下面看到适合我的完整解决方案.谢谢Tapas Bose的原始解决方案.我希望这对任何人都有帮助!

BufferedImage originalImage = Utils.prepareBufferedImage(fileUpload.getFile_data(), fileUpload.getFile_type());
                    BufferedImage scaledImg = Scalr.resize(originalImage, 200);

                    // ---- Begin orientation handling ----
                    Metadata metadata = ImageMetadataReader.readMetadata(fileUpload.getFile_data());
                    ExifIFD0Directory exifIFD0Directory = metadata.getFirstDirectoryOfType(ExifIFD0Directory.class);

                    int orientation = Integer.parseInt(id);
                    try {
                        orientation = exifIFD0Directory.getInt(ExifIFD0Directory.TAG_ORIENTATION);
                    } catch (Exception ex) {
                        logger.debug("No EXIF information found for image: " + fileUpload.getFile_name());
                    }

                    switch (orientation) {
                    case 1:
                        break;
                    case 2: // Flip X
                        scaledImg = Scalr.rotate(scaledImg, Rotation.FLIP_HORZ);
                        break;
                    case 3: // PI rotation
                        scaledImg = Scalr.rotate(scaledImg, Rotation.CW_180);
                        break;
                    case 4: // Flip Y
                        scaledImg = Scalr.rotate(scaledImg, Rotation.FLIP_VERT);
                        break;
                    case 5: // - PI/2 and Flip X
                        scaledImg = Scalr.rotate(scaledImg, Rotation.CW_90);
                        scaledImg = Scalr.rotate(scaledImg, Rotation.FLIP_HORZ);
                        break;
                    case 6: // -PI/2 and -width
                        scaledImg = Scalr.rotate(scaledImg, Rotation.CW_90);
                        break;
                    case 7: // PI/2 and Flip
                        scaledImg = Scalr.rotate(scaledImg, Rotation.CW_90);
                        scaledImg = Scalr.rotate(scaledImg, Rotation.FLIP_VERT);
                        break;
                    case 8: // PI / 2
                        scaledImg = Scalr.rotate(scaledImg, Rotation.CW_270);
                        break;
                    default:
                        break;
                    }       
                    // ---- End orientation handling ----

                    if(fileUpload.getFile_type().toLowerCase().contains("jpeg")){
                        ImageIO.write(scaledImg, "jpeg", fileUpload.getFile_data());
                        user.setProfile_picture_ext("jpg");
                    }
                    else{
                        Sanselan.writeImage(scaledImg, fileUpload.getFile_data(), ImageFormat.IMAGE_FORMAT_PNG, null);
                        user.setProfile_picture_ext("png");
                    }