How to save a JPEG image on Android with a custom quality level
On Android, how do I save an image file as a JPEG at 30% quality?
In standard Java, I would use ImageIO
to read the image as a BufferedImage
, then save it as a JPEG file using an IIOImage
instance: http://www.universalwebservices.net/web-programming-resources/java/adjust-jpeg-image-compression-quality-when-saving-images-in-java. It appears, however, that Android lacks the javax.imageio
package.
You can store your bitmap in the JPEG format by calling compress and setting the second parameter:
Bitmap bm2 = createBitmap();
OutputStream stream = new FileOutputStream("/sdcard/test.jpg");
/* Write bitmap to file using JPEG and 80% quality hint for JPEG. */
bm2.compress(CompressFormat.JPEG, 80, stream);
InputStream in = new FileInputStream(file);
try {
Bitmap bitmap = BitmapFactory.decodeStream(in);
File tmpFile = //...;
try {
OutputStream out = new FileOutputStream(tmpFile);
try {
if (bitmap.compress(CompressFormat.JPEG, 30, out)) {
{ File tmp = file; file = tmpFile; tmpFile = tmp; }
tmpFile.delete();
} else {
throw new Exception("Failed to save the image as a JPEG");
}
} finally {
out.close();
}
} catch (Throwable t) {
tmpFile.delete();
throw t;
}
} finally {
in.close();
}
@Phyrum Tea is good only do not forget close everything
InputStream in = new FileInputStream(context.getFilesDir() + "image.jpg");
Bitmap bm2 = BitmapFactory.decodeStream(in);
OutputStream stream = new FileOutputStream(String.valueOf(
context.getFilesDir() + pathImage + "/" + idPicture + ".jpg"));
bm2.compress(Bitmap.CompressFormat.JPEG, 50, stream);
stream.close();
in.close();
Using Kotlin to save a file in path
to tmpPath
:
Files.newInputStream(path).use { inputStream ->
Files.newOutputStream(tmpPath).use { tmpOutputStream ->
BitmapFactory
.decodeStream(inputStream)
.compress(Bitmap.CompressFormat.JPEG, 30, tmpOutputStream)
}
}
Edit: make sure you check for the possibility of the decode failing (and returning null) and also that compress actually worked (boolean return type).
val success: Boolean = Files.newInputStream(path).use { inputStream ->
Files.newOutputStream(tmpPath).use { tmpOutputStream ->
BitmapFactory
.decodeStream(inputStream)
?.compress(Bitmap.CompressFormat.JPEG, config.qualityLevel, tmpOutputStream)
?: throw Exception("Failed to decode image")
}
}
if (!success) {
throw Exception("Failed to compress and save image")
}