使用 imagemagick 旋转
查看照片 EXIF 信息，Exif 中的图片旋转信息储存在Orientation中。
identify -verbose xxx.jpg
自动识别并旋转图片
convert xxx.jpg -auto-orient yyy.jpg
Orientation 可能的值
| Value | 0th Row | 0th Column | 逆时针旋转的角度 |
|---|---|---|---|
1 |
top |
left side |
0 |
2* |
top |
right side |
- |
3 |
bottom |
right side |
180 |
4* |
bottom |
left side |
- |
5* |
left side |
top |
- |
6 |
right side |
top |
90 |
7* |
right side |
bottom |
- |
8 |
left side |
bottom |
270 |
使用 JS 旋转
使用exif-js可以获取到相关 Exif 信息。
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>图片旋转demo</title>
<style>
.img-90 {
transform:rotate(90deg);
-ms-transform:rotate(90deg); /* IE 9 */
-moz-transform:rotate(90deg); /* Firefox */
-webkit-transform:rotate(90deg); /* Safari 和 Chrome */
-o-transform:rotate(90deg); /* Opera */
}
</style>
<script type="text/javascript" src="./static/thirdparty/exif-js.js"></script>
<script>
window.onload=getExif;
var Orientations = {
'1': 0,
'3': 180,
'6': 90,
'8': 270
};
function getExif() {
var img1 = document.getElementById("img1");
EXIF.getData(img1, function() {
var orientation = EXIF.getTag(this, "Orientation");
var makeAndModel = document.getElementById("orientation1");
makeAndModel.innerHTML = Orientations[orientation];
document.getElementById('img1').classList.add('img-' + Orientations[orientation]);
});
}
</script>
</head>
<body>
<div style="border: 1px solid black;width:300px;margin-right:5px;float: left;">
<img id="img1" src="./static/images/fp.png" style="max-width:300px" />
{gfm-js-extract-pre-1}
</div>
</body>
</html>
旋转时可以通过以上css3方式简易实现，还可以通过canvas绘制实现。
使用 Java 旋转
import com.drew.imaging.ImageMetadataReader;
import com.drew.metadata.Directory;
import com.drew.metadata.Metadata;
import com.drew.metadata.exif.ExifIFD0Directory;
import org.apache.commons.lang3.StringUtils;
import java.awt.Dimension;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
public class ImageRotateDemo {
/**
* 对图片进行旋转
*
* @param src
* 被旋转图片
* @param angel
* 旋转角度
* @return 旋转后的图片
*/
public static BufferedImage rotate(Image src, int angel) {
int src_width = src.getWidth(null);
int src_height = src.getHeight(null);
// 计算旋转后图片的尺寸
Rectangle rect_des = CalcRotatedSize(new Rectangle(new Dimension(src_width, src_height)), angel);
BufferedImage res = null;
res = new BufferedImage(rect_des.width, rect_des.height, BufferedImage.TYPE_INT_RGB);
Graphics2D g2 = res.createGraphics();
// 进行转换
g2.translate((rect_des.width - src_width) / 2, (rect_des.height - src_height) / 2);
g2.rotate(Math.toRadians(angel), src_width / 2, src_height / 2);
g2.drawImage(src, null, null);
return res;
}
/**
* 计算旋转后的图片
*
* @param src
* 被旋转的图片
* @param angel
* 旋转角度
* @return 旋转后的图片
*/
public static Rectangle CalcRotatedSize(Rectangle src, int angel) {
// 如果旋转的角度大于90度做相应的转换
if (angel >= 90) {
if (angel / 90 % 2 == 1) {
int temp = src.height;
src.height = src.width;
src.width = temp;
}
angel = angel % 90;
}
double r = Math.sqrt(src.height * src.height + src.width * src.width) / 2;
double len = 2 * Math.sin(Math.toRadians(angel) / 2) * r;
double angel_alpha = (Math.PI - Math.toRadians(angel)) / 2;
double angel_dalta_width = Math.atan((double) src.height / src.width);
double angel_dalta_height = Math.atan((double) src.width / src.height);
int len_dalta_width = (int) (len * Math.cos(Math.PI - angel_alpha - angel_dalta_width));
int len_dalta_height = (int) (len * Math.cos(Math.PI - angel_alpha - angel_dalta_height));
int des_width = src.width + len_dalta_width * 2;
int des_height = src.height + len_dalta_height * 2;
return new Rectangle(new Dimension(des_width, des_height));
}
/**
* 获得图片调整角度
*
* @param imgFile
* @return
*/
public static Integer getImgRotateAngle(String imgFile) {
Integer angel = 0;
Metadata metadata = null;
try {
if (StringUtils.isBlank(imgFile))
return angel;
File _img_file_ = new File(imgFile);
if (!_img_file_.exists())
return angel;
metadata = ImageMetadataReader.readMetadata(_img_file_);
Directory directory = metadata.getDirectory(ExifIFD0Directory.class);
if (directory != null && directory.containsTag(ExifIFD0Directory.TAG_ORIENTATION)) {
int orientation = directory.getInt(ExifIFD0Directory.TAG_ORIENTATION);
// 原图片的方向信息
if (6 == orientation) {
// 6旋转90
angel = 90;
} else if (3 == orientation) {
// 3旋转180
angel = 180;
} else if (8 == orientation) {
// 8旋转90
angel = 270;
}
}
} catch (Exception e) {
e.printStackTrace();
}
return angel;
}
/**
* 调整图片角度
*
* @param imgFile
*/
public static void rotateImage(String imgFile) {
try {
if (StringUtils.isBlank(imgFile)) {
File _img_file_ = new File(imgFile);
if (_img_file_.exists()) {
Integer angel = getImgRotateAngle(imgFile);
if (angel == 0)
return;
BufferedImage src = ImageIO.read(_img_file_);
BufferedImage des = rotate(src, angel);
ImageIO.write(des, "jpg", _img_file_);
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
public static void main(String[] args) throws Exception {
String fromPic = "D:\\MyProject\\Test\\resource\\fp.png";
// rotateImage(file);
Integer angel = getImgRotateAngle(fromPic);
System.out.println(angel);
if (angel > 0) {
BufferedImage src = ImageIO.read(new File(fromPic));
// 顺时针旋转270度
BufferedImage des3 = rotate(src, 270);
ImageIO.write(des3, "png", new File("D:\\MyProject\\Test\\resource\\fp_270.png"));
}
System.out.println("==End==");
}
}
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