Develop Reference

How to properly screenshot an android device?

The image that I get has a segment from the middle of the phone as an artifact on the right.
Android Code
I use MediaProjection and ImageReader.
//OnCreate
display = getWindowManager().getDefaultDisplay();
display.getSize(displaySize);
display.getMetrics(displayMetrics);
imageReader = ImageReader.newInstance(displaySize.x, displaySize.y,
PixelFormat.RGBA_8888, 2);
//onActivityResult
mediaProjection.createVirtualDisplay("screen", displaySize.x, displaySize.y,
displayMetrics.densityDpi, DisplayManager.VIRTUAL_DISPLAY_FLAG_AUTO_MIRROR,
imageReader.getSurface(), null, null);
//ScheduledThread
Image image = imageReader.acquireLatestImage();
if(image != null) {
final Image.Plane[] planes = image.getPlanes();
int pixelStride = planes[0].getPixelStride();
int rowStride = planes[0].getRowStride();
int rowPadding = rowStride - pixelStride * image.getWidth();
ByteBuffer buffer = image.getPlanes()[0].getBuffer();
Bitmap bitmap = Bitmap.createBitmap(image.getWidth() + rowPadding /
pixelStride, image.getHeight(), Bitmap.Config.ARGB_8888);
bitmap.copyPixelsFromBuffer(buffer);
byte[] byteArray;
if(bitmap != null) {
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG,50,byteArrayOutputStream);
byteArray = byteArrayOutputStream.toByteArray();
String encoded = Base64.encodeToString(byteArray, Base64.DEFAULT);
socket.emit("frame", encoded);
}
image.close();
}
Java Code
socket.on("frame", args1 -> {
byte[] bytes = Base64.getMimeDecoder().decode((String)args1[0]);
ByteArrayInputStream bin = new ByteArrayInputStream(bytes);
try {
BufferedImage img = ImageIO.read(bin);
int type = img.getType() == 0 ? BufferedImage.TYPE_INT_ARGB : img.getType();
img = resizeImage(img, type);
if(!frameOpen){
openFrame(img.getWidth());
}
panel.removeAll();
panel.add(new JLabel(new ImageIcon(img)));
frame.pack();
} catch (IOException ex) {
ex.printStackTrace();
}
});
private static BufferedImage resizeImage(BufferedImage originalImage, int type) {
double ratio = 1.0 * originalImage.getWidth() / originalImage.getHeight();
int imgHeight = Toolkit.getDefaultToolkit().getScreenSize().height - 100;
BufferedImage resizedImage = new BufferedImage((int) ((int)imgHeight*ratio), imgHeight, type);
Graphics2D g = resizedImage.createGraphics();
g.drawImage(originalImage, 0, 0, (int) ((int)imgHeight*ratio), imgHeight, null);
g.dispose();
return resizedImage;
}
Result
As you can see in the image, on the far right, that thin line is from the middle portion of the image.
What do you think is causing this?
EDIT: I know for a fact it's an error in the android code. Could my ImageReader or createVirtualDisplay be set up wrong?
I was able to get rid of the black bars by using:
display.getRealSize(displaySize);
But that line segment is still there:
Repo
https://github.com/Decapitated/Android-Viewer

Image file doesn't overwrite unless restart the TomCat

I created a java web application. In which i created program to resize and upload photos. This stored in a specific folder. When I changes the Photo it doesn't change and remains the old photo. But after restarting the TomCat I can change the photo. Why would this happen? Here is the code to resize and store image
public static int createThumbnailNew(String original,
String resized, int maxSize) {
try
{
File originalFile = new File(original);
ImageIcon ii = new ImageIcon(originalFile.getCanonicalPath());
Image i = ii.getImage();
int iWidth = i.getWidth(null);
int iHeight = i.getHeight(null);
BufferedImage originalImage = new BufferedImage(
i.getWidth(null), i.getHeight(null),
BufferedImage.TYPE_INT_RGB);
// Copy image to buffered image.
Graphics g = originalImage.createGraphics();
// Clear background and paint the image.
g.setColor(Color.white);
g.fillRect(0, 0, i.getWidth(null), i.getHeight(null));
g.drawImage(i, 0, 0, null);
g.dispose();
BufferedImage bufferedImage = null;
if (iWidth > iHeight) {
bufferedImage = resizeImage(originalImage, BufferedImage.TYPE_INT_RGB,(maxSize * iHeight)/iWidth,maxSize);
} else {
bufferedImage = resizeImage(originalImage, BufferedImage.TYPE_INT_RGB,maxSize,(maxSize * iWidth) / iHeight);
}
//BufferedImage croppedImage=cropImage(bufferedImage,crX,crY,crH,crW);
File file = new File(resized);
FileOutputStream out = new FileOutputStream(file);
/* encodes image as a JPEG data stream */
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
com.sun.image.codec.jpeg.JPEGEncodeParam param = encoder
.getDefaultJPEGEncodeParam(bufferedImage);
// writeParam = new JPEGImageWriteParam(null);
// writeParam.setCompressionMode(JPEGImageWriteParam.MODE_EXPLICIT);
// writeParam.setProgressiveMode(JPEGImageWriteParam.MODE_DEFAULT);
param.setQuality(1.0f, true);
encoder.setJPEGEncodeParam(param);
encoder.encode(bufferedImage);
}
catch(Exception e)
{
return -1;
}
return 0;
}
private static BufferedImage resizeImage(BufferedImage originalImage, int type,int h,int w){
BufferedImage resizedImage = new BufferedImage(w, h, type);
Graphics2D g = resizedImage.createGraphics();
g.drawImage(originalImage, 0, 0, w, h, null);
g.dispose();
return resizedImage;
}
Please Help.. Thanks..

You haven't closed your opened files. That is one possible problem here.

What is BufferedImageOp stands for?

I just want to enlarge a BufferedImage and make a watermark on it.Here is my code.
BufferedImage image = GetHtmlImage(doc, base_url, width, -1);
if (image.getHeight() < MaxShortHeight) {
return "";
}
BufferedImage gimage = new BufferedImage(image.getWidth(), image.getHeight() + 20, BufferedImage.TYPE_INT_RGB);
Graphics2D g2 = gimage.createGraphics();
g2.setBackground(Color.WHITE);
g2.drawImage(image, BufferedImageOp, 0, 0);
g2.setColor(Color.BLACK);
g2.drawString("Press by Shisoft WebFusion http://www.shisoft.net/", 10, image.getHeight() - 10);
ByteArrayOutputStream os = new ByteArrayOutputStream();
ImageIO.write(gimage, "jpeg", os);
At 'g2.drawImage(image, BufferedImageOp, 0, 0);'.I don't know what is BufferedImageOp.Could someone make an example.
Thank you.

How to decrease image thumbnail size in java

I have an image a.jpg with size 4.7kb, when its upload to web-server, its size become 15.5KB ...
I am using following code.
BufferedImage bi = ImageIO.read(business.getImage()); //business is sturts2 Form & image instance of File class
int height = bi.getHeight();
int width = bi.getWidth();
if (height > Constants.BIZ_IMAGE_HEIGHT || width > Constants.BIZ_IMAGE_WIDTH) {
height = Constants.BIZ_IMAGE_HEIGHT;
width = Constants.BIZ_IMAGE_WIDTH;
}
InputStream is = UtilMethod.scaleImage(new FileInputStream(business.getImage()), width, height);
File f = new File(businessImagesPath, business.getImageFileName());
UtilMethod.saveImage(f, is);
is.close();
UtilMethod.scaleImage(..) ... is as follow:
public static InputStream scaleImage(InputStream p_image, int p_width, int p_height) throws Exception {
InputStream imageStream = new BufferedInputStream(p_image);
Image image = (Image) ImageIO.read(imageStream);
int thumbWidth = p_width;
int thumbHeight = p_height;
// Make sure the aspect ratio is maintained, so the image is not skewed
double thumbRatio = (double) thumbWidth / (double) thumbHeight;
int imageWidth = image.getWidth(null);
int imageHeight = image.getHeight(null);
double imageRatio = (double) imageWidth / (double) imageHeight;
if (thumbRatio < imageRatio) {
thumbHeight = (int) (thumbWidth / imageRatio);
} else {
thumbWidth = (int) (thumbHeight * imageRatio);
}
// Draw the scaled image
BufferedImage thumbImage = new BufferedImage(thumbWidth,
thumbHeight, BufferedImage.TYPE_INT_RGB);
Graphics2D graphics2D = (Graphics2D) thumbImage.createGraphics();
graphics2D.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
RenderingHints.VALUE_INTERPOLATION_BILINEAR);
graphics2D.drawImage(image, 0, 0, thumbWidth, thumbHeight, Color.WHITE, null);
// Write the scaled image to the outputstream
ByteArrayOutputStream out = new ByteArrayOutputStream();
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(thumbImage);
int quality = 85; // Use between 1 and 100, with 100 being highest quality
quality = Math.max(0, Math.min(quality, 100));
param.setQuality((float) quality / 100.0f, false);
encoder.setJPEGEncodeParam(param);
encoder.encode(thumbImage);
ImageIO.write(thumbImage, "png", out);
ByteArrayInputStream bis = new ByteArrayInputStream(out.toByteArray());
return bis;
}
Any other size and quality optimization idea while saving images using java. I am using struts2 MVC ... thank u so much.

int quality = 85; // Use between 1 and 100, with 100 being highest quality
This seems like a high quality for a JPEG thumbnail. Try around 60 or 50.
quality = Math.max(0, Math.min(quality, 100));
Huh?
param.setQuality((float) quality / 100.0f, false);
encoder.setJPEGEncodeParam(param);
OK..
encoder.encode(thumbImage);
ImageIO.write(thumbImage, "png", out);
But huh? Why set a JPEGEncodeParam and store as a PNG? Does that even have any effect? Try..
ImageIO.write(thumbImage, "jpg", out);

JAI Change JPEG Resolution

I am having difficulty using the Java JAI (Java Advance Imaging) API to change the resolution of a JPEG image from lets say 1024x800 to 512x400.
I have played around with the API and keep getting stream or java.lang.OutOfMemory exceptions.
Anyone with a working example.

Here's one using JAI
public void resize(String filename, RenderedOp image, double wScale, double hScale)
{
// now resize the image
ParameterBlock pb = new ParameterBlock();
pb.addSource(image); // The source image
pb.add(wScale); // The xScale
pb.add(hScale); // The yScale
pb.add(0.0F); // The x translation
pb.add(0.0F); // The y translation
RenderingHints hints = new RenderingHints(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
RenderedOp resizedImage = JAI.create("SubsampleAverage", pb, hints);
// lastly, write the newly-resized image to an
// output stream, in a specific encoding
try
{
FileOutputStream fos = new FileOutputStream(new File(filename));
JAI.create("encode", resizedImage, fos, getImageType(filename), null);
}
catch (FileNotFoundException e)
{
}
}

Here's a working example, supplied on an "as is" basis with no warranty :)
BufferedImage scaleImage(BufferedImage sourceImage, int scaledWidth) {
float scale = scaledWidth / (float) sourceImage.getWidth();
int scaledHeight = (int) (sourceImage.getHeight() * scale);
Image scaledImage = sourceImage.getScaledInstance(
scaledWidth,
scaledHeight,
Image.SCALE_AREA_AVERAGING
);
BufferedImage bufferedImage = new BufferedImage(
scaledImage.getWidth(null),
scaledImage.getHeight(null),
BufferedImage.TYPE_INT_RGB
);
Graphics g = bufferedImage.createGraphics();
g.drawImage(scaledImage, 0, 0, null);
g.dispose();
return bufferedImage;
}