Android - ImageUtils

ImageUtils.java

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Rect;
import android.media.ExifInterface;

import java.io.File;
import java.io.IOException;

/**
 * 画像関連の共通メソッド
 * @author D.furiya
 */
public class ImageUtils {

	/**
	 * Bitmap画像を縦横サイズにリサイズ
	 * @param org 編集前のBitmap
	 * @param destWidth 指定横幅サイズ
	 * @param destHeight 指定縦幅サイズ
	 * @return Bitmap リサイズ画像
	 */
	public static Bitmap resizeBitmap(Bitmap org, int destWidth, int destHeight) {

		// 空のbitmap、背景は全透明
		Bitmap blankResized = Bitmap.createBitmap(destWidth, destHeight, Bitmap.Config.ARGB_8888);

		// 縦縮か横縮尺か判定
		int xPadding = 0;
		int yPadding = 0;
		int scaledWidth = blankResized.getWidth();
		int scaledHeight = blankResized.getHeight();
		float scale = 1;
		if (org.getWidth() > org.getHeight()) {
			// 縮尺とパディングの設定
			scale = (float) blankResized.getWidth() / (float) org.getWidth();
			scaledHeight = (int) (org.getHeight() * scale);
			yPadding = (blankResized.getHeight() - scaledHeight) / 2;
		}
		else {
			// 縮尺とパディングの設定
			scale = (float) blankResized.getHeight() / (float) org.getHeight();
			scaledWidth = (int) (org.getWidth() * scale);
			xPadding = (blankResized.getWidth() - scaledWidth) / 2;
		}

		// 画像を縮小してコピーするときれいになる
		Bitmap orgScale = Bitmap.createScaledBitmap(org, scaledWidth, scaledHeight, true);
		Canvas canvas = new Canvas(blankResized);
		canvas.drawBitmap(
				orgScale,
				new Rect(0, 0, scaledWidth, scaledHeight),
				new Rect(xPadding, yPadding, xPadding + scaledWidth, yPadding + scaledHeight),
				null);

		return blankResized;
	}

	public static Bitmap rotateImage(final Bitmap bitmap, final File fileWithExifInfo) {
		Bitmap rotatedBitmap = bitmap;
		int orientation = 0;
		try {
			orientation = getImageOrientation(fileWithExifInfo.getAbsolutePath());
			if (orientation != 0) {
				final Matrix matrix = new Matrix();
				matrix.postRotate(orientation);
				rotatedBitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(),
						bitmap.getHeight(), matrix, true);
				bitmap.recycle();
			}
		} catch (final IOException e) {
		}
		return rotatedBitmap;
	}

	public static int getImageOrientation(final String file) throws IOException {
		final ExifInterface exif = new ExifInterface(file);
		final int orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, 1);
		switch (orientation) {
			case ExifInterface.ORIENTATION_NORMAL:
				return 0;
			case ExifInterface.ORIENTATION_ROTATE_90:
				return 90;
			case ExifInterface.ORIENTATION_ROTATE_180:
				return 180;
			case ExifInterface.ORIENTATION_ROTATE_270:
				return 270;
			default:
				return 0;
		}
	}

	public static int getOrientation(final int orientation) {
		switch (orientation) {
			case 0:
				return ExifInterface.ORIENTATION_NORMAL;
			case 90:
				return ExifInterface.ORIENTATION_ROTATE_90;
			case 180:
				return ExifInterface.ORIENTATION_ROTATE_180;
			case 270:
				return ExifInterface.ORIENTATION_ROTATE_270;
			default:
				return 0;
		}
	}
}