I would like to add Watermark to my Bitmap. Since the bitmap is retrieved from server, I need to add the watermark in the Async Task. I have tried to use bellow code:
int w = src.getWidth();
int h = src.getHeight();
Bitmap result = Bitmap.createBitmap(w, h, src.getConfig());
Canvas canvas = new Canvas(result);
canvas.drawBitmap(src, 0, 0, null);
Bitmap waterMark = BitmapFactory.decodeResource(mContext.getResources(), R.drawable.logo);
canvas.drawBitmap(waterMark, 0, 0, null);
However, I got
NullPointerException error
What is wrong? Is it not possible to add watermark to an image in Async Task? Thanks a lot.
Related
I've got a bitmap displayed in an ImageView, and I want to be able to make a certain percentage of the image black and white, and have the other part retain it's color. For example, if 60% is the target percentage, the image would look like this: . Thanks.
I've got a bitmap displayed in an ImageView, and I want to be able to
make a certain percentage of the image black and white, and have the
other part retain it's color. For example, if 60% is the target
percentage.
It seems (from your image) you mean monochrome (i.e. greyscale), not black and white.
Something like this should do it (tested o.k.):
void doIt(ImageView image)
{
//get bitmap from your ImageView (image)
Bitmap originalBitmap = ((BitmapDrawable)image.getDrawable()).getBitmap();
int height = originalBitmap.getHeight();
int fortyPercentHeight = (int) Math.floor(height * 40.0 / 100.0);
//create a bitmap of the top 40% of image height that we will make black and white
Bitmap croppedBitmap = Bitmap.createBitmap(originalBitmap, 0, 0, originalBitmap.getWidth() , fortyPercentHeight );
//make it monochrome
Bitmap blackAndWhiteBitmap = monoChrome(croppedBitmap);
//copy the monochrome bmp (blackAndWhiteBitmap) to the original bmp (originalBitmap)
originalBitmap = overlay(originalBitmap, blackAndWhiteBitmap);
//set imageview to new bitmap
image.setImageBitmap(originalBitmap );
}
Bitmap monoChrome(Bitmap bitmap)
{
Bitmap bmpMonochrome = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bmpMonochrome);
ColorMatrix ma = new ColorMatrix();
ma.setSaturation(0);
Paint paint = new Paint();
paint.setColorFilter(new ColorMatrixColorFilter(ma));
canvas.drawBitmap(bitmap, 0, 0, paint);
return bmpMonochrome;
}
Bitmap overlay(Bitmap bmp1, Bitmap bmp2)
{
Bitmap bmp3 = bmp1.copy(Bitmap.Config.ARGB_8888,true);//mutable copy
Canvas canvas = new Canvas(bmp3 );
canvas.drawBitmap(bmp2, new Matrix(), null);
return bmp3 ;
}
I have a requirement, like drawing something in canvas and saving it to a larger image. As of now whatever I draw inside onDraw() method and save, it gives device provided image/canvas size, say something around 538(w)/852(h). I need image of almost double size, around 1000(w)/1500(h) without losing resolution. Any sample code, reference link would help definitely. Thanks in advance.
One way is to create Bitmap of desired size and draw on it using canvas:
int w = 1000, h = 1500;
Bitmap.Config conf = Bitmap.Config.ARGB_8888;
Bitmap bmp = Bitmap.createBitmap(w, h, conf);
Canvas canvas = new Canvas(bmp);
Finally you will have you bmp with your drawing and necessary dimentions.
EDIT::
#Override
protected void onDraw(Canvas canvas) {
int w = 1000, h = 1500;
Bitmap.Config conf = Bitmap.Config.ARGB_8888;
Bitmap bmp = Bitmap.createBitmap(w, h, conf);
Canvas mycanvas = new Canvas(bmp);
super.onDraw(mycanvas);
...
}
First get bitmap of your view using the function getDrawingCache(), then scale the bitmap as per your requirements.
view.buildDrawingCache();
Bitmap bitmap = view.getDrawingCache();
//bitmap = bitmap.createScaledBitmap(..as your requirements..);
EDIT
You are saying that you want image in higher quality. You can't simply get a higher quality image from a lower quality image. However you can apply bitmap filtering to get slightly better quality.
Bitmap bitmap = getDrawingCache();
Bitmap output = Bitmap.createBitmap(/*width, height, bla bla bla*/);
Canvas canvas = new Canvas(output);
Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG);
Rect srcRect = new Rect(0,0,bitmap.getWidth(), bitmap.getHeight());
Rect destRect = new Rect(0,0,output.getWidth(), output.getHeight());
canvas.drawBitmap(bitmap, srcRect, destRect, paint);
I am using View in android and I need to convert this to Bitmap without adding this into the activity.
view.setDrawingCacheEnabled(true);
Bitmap bitmap= view.getDrawingCache();
It returns bitmap as null.
Also I have tried the method view.buildDrawingCache() but still getDrawingCache() return null.
Thanks in advance.
First you need to create empty bitmap and get canvas from it.
use below code for this
int w = WIDTH_PX, h = HEIGHT_PX;
Bitmap.Config conf = Bitmap.Config.ARGB_8888; // see other conf types
Bitmap bmp = Bitmap.createBitmap(w, h, conf); // this creates a MUTABLE bitmap
Canvas canvas = new Canvas(bmp);
Now you need to draw you view in this bitmap.
use below code for this
LinearLayout layout = new LinearLayout(getContext());
TextView textView = new TextView(getContext());
int padding = 4;
textView.setPadding(padding, padding, padding, padding);
textView.setVisibility(View.VISIBLE);
textView.setText("Hello how are you");
layout.addView(textView);
textView.setTextSize(TypedValue.COMPLEX_UNIT_SP, 10);
layout.measure(canvas.getWidth(), canvas.getHeight());
layout.layout(0, 0, canvas.getWidth(), canvas.getHeight());
layout.draw(canvas);
now your view is converted into the bitmap (bmp).
I want to take only a part of the the screen data from a preview video callback to reduce the time of the process. The probleme is I only know how to take the whole screen with OnPreviewFrame:
#Override
public void onPreviewFrame(byte[] data, Camera camera) {
myData = data;
// +get camera resolution x, y
}
And then with this data get the image :
private Bitmap getBitmapFromYUV(byte[] data, int width, int height)
{
ByteArrayOutputStream out = new ByteArrayOutputStream();
YuvImage yuvImage = new YuvImage(data, ImageFormat.NV21, width, height, null);
yuvImage.compressToJpeg(new Rect(0, 0, width, height), 100, out);
byte[] imageBytes = out.toByteArray();
Bitmap image = BitmapFactory.decodeByteArray(imageBytes, 0, imageBytes.length);
return image;
}
And then I take the part of the image taken I want :
cutImage = Bitmap.createBitmap(image, xOffset, yOffset, customWidth, customHeight);
The problem is that I need to take lots of images to apply some image processing on it and that's why I want to reduce the time it takes to get the images. Instead of taking the whole screen and then crop it, I want to immediatly get the cropped image. Is there a way to get the part of the screen data ?
Ok I finally found something, I still record all the data of the camera but when using compressToJpeg I crop the picture with a custom Rect. Maybe there is something better to do before this but this is still a good improvement. Here are my changes :
yuvImage.compressToJpeg(new Rect(offsetX, offsetY, sizeCaptureX + offsetX, sizeCaptureY + offsetY ), 100, out);
I want to resize a .tiff file. I have used JAI toolkit to resize different types of images. Here is what I have tried to implement:
int imageWidth = 330;
int imageHeight = 490;
BufferedImage tempImage = new BufferedImage(imageWidth, imageHeight,BufferedImage.TYPE_INT_RGB);
Graphics2D graphics2D = tempImage.createGraphics();
graphics2D.setRenderingHint(RenderingHints.KEY_INTERPOLATION,RenderingHints.VALUE_INTERPOLATION_BICUBIC);
graphics2D.drawImage(tempImage, 0, 0, imageWidth, imageHeight, null);
graphics2D.dispose();
File outfile = new File("D:/Work/YoursGallery/output.tif");
BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream(outfile));
FileSeekableStream ss = new FileSeekableStream("D:/Work/YoursGallery/sample1.tif");
ImageDecoder dec = ImageCodec.createImageDecoder("tiff", ss, null);
TIFFEncodeParam param = new TIFFEncodeParam();
param.setTileSize(tempImage.getWidth(), tempImage.getHeight());
TIFFImageEncoder encoder = (TIFFImageEncoder) TIFFCodec.createImageEncoder("tiff", out, param);
encoder.encode(dec.decodeAsRenderedImage());
out.close();
The image created is having same size as original image has. Can anyone please tell what is the issue?
Here is the sample tiff image which I am using to test it.
http://docs.google.com/fileview?id=0BxCDhEXNFvbeMTYyMGZmNDYtODhhNy00YWI3LTkxNDgtZTNhM2FhMjg5Y2Q3&hl=en&authkey=CPCEypgM
Thanks in advance.
That's because you are writing out tempImage which is still the original image.
graphics2D.drawImage(image, 0, 0, imageWidth, imageHeight, null);
change that to:
graphics2D.drawImage(tempImage, 0, 0, imageWidth, imageHeight, null);
or change your other code to write out image instead of tempImage
--Edit--
OK Attempt 2. Maybe having the source and destination the same is daft.
BufferedImage bsrc = ImageIO.read(new File(src));
BufferedImage bdest =
new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics2D g = bdest.createGraphics();
AffineTransform at =
AffineTransform.getScaleInstance((double)width/bsrc.getWidth(),
(double)height/bsrc.getHeight());
g.drawRenderedImage(bsrc,at);
Try that :)
1) You are writing tempImage inside itself:
graphics2D.drawImage(tempImage, 0, 0, imageWidth, imageHeight, null);
Should be:
graphics2D.drawImage(originalImage, 0, 0, imageWidth, imageHeight, null);
2) You are writing the image that you just read (why are You reading it btw?):
encoder.encode(dec.decodeAsRenderedImage());
Should be:
encoder.encode(tempImage);