Files
pointspermis/tesseract/src/main/java/com/googlecode/leptonica/android/JpegIO.java
2015-01-29 23:47:56 +01:00

89 lines
2.8 KiB
Java

/*
* Copyright (C) 2011 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.googlecode.leptonica.android;
import android.graphics.Bitmap;
import android.graphics.Bitmap.CompressFormat;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
/**
* JPEG input and output methods.
*
* @author alanv@google.com (Alan Viverette)
*/
public class JpegIO {
static {
System.loadLibrary("lept");
}
/** Default quality is 85%, which is reasonably good. */
public static final int DEFAULT_QUALITY = 85;
/** Progressive encoding is disabled by default to increase compatibility. */
public static final boolean DEFAULT_PROGRESSIVE = false;
/**
* Returns a compressed JPEG byte representation of this Pix using default
* parameters.
*
* @param pixs
* @return a compressed JPEG byte array representation of the Pix
*/
public static byte[] compressToJpeg(Pix pixs) {
return compressToJpeg(pixs, DEFAULT_QUALITY, DEFAULT_PROGRESSIVE);
}
/**
* Returns a compressed JPEG byte representation of this Pix.
*
* @param pixs A source pix image.
* @param quality The quality of the compressed image. Valid range is 0-100.
* @param progressive Whether to use progressive compression.
* @return a compressed JPEG byte array representation of the Pix
*/
public static byte[] compressToJpeg(Pix pixs, int quality, boolean progressive) {
if (pixs == null)
throw new IllegalArgumentException("Source pix must be non-null");
if (quality < 0 || quality > 100)
throw new IllegalArgumentException("Quality must be between 0 and 100 (inclusive)");
final ByteArrayOutputStream byteStream = new ByteArrayOutputStream();
final Bitmap bmp = WriteFile.writeBitmap(pixs);
bmp.compress(CompressFormat.JPEG, quality, byteStream);
bmp.recycle();
final byte[] encodedData = byteStream.toByteArray();
try {
byteStream.close();
} catch (IOException e) {
e.printStackTrace();
}
return encodedData;
}
// ***************
// * NATIVE CODE *
// ***************
private static native byte[] nativeCompressToJpeg(
long nativePix, int quality, boolean progressive);
}