Develop Reference

how can i get a high quality picture from a view’s screenshots

I want to get the picture of the view（not ImageView） inside，but the picture I got was not clear,Of course the original picture is clear ,here is my codes
public static Bitmap getDrawBitmap(View designView){
designView.destroyDrawingCache();
designView.setDrawingCacheEnabled(true);
designView.setDrawingCacheQuality(View.DRAWING_CACHE_QUALITY_HIGH);
return designView.getDrawingCache();
}
I have tried to scale the View,and then getDrawingCache(),but it didn't work,the view's size didn't change
Bitmap bitmap=ImgUtils.getDrawBitmap(testBtn);
float w=1260f;
float h=1660f;
float x= w/(bitmap.getWidth()/DrawAttribute.density);
float y= h/(bitmap.getHeight()/DrawAttribute.density);
Log.e("x-y",x+"-"+y);
Bitmap result=Bitmap.createBitmap(1260,1660,Bitmap.Config.ARGB_8888);
Canvas offScreen = new Canvas(result);
Matrix matrix=new Matrix();
matrix.setScale(x,y);
offScreen.drawBitmap(bitmap, matrix, null);
//存储路径
OutputStream stream = null;
try {
if (LiApplication.creatDir()) {
stream = new FileOutputStream(Environment.getExternalStorageDirectory()+ "/yc/img/"
+ "save.png");
}
} catch (FileNotFoundException e) {
}
Bitmap.CompressFormat format = Bitmap.CompressFormat.PNG;
result.compress(format, 100, stream);

This is a Demo code for taking screen shot of whole View.
View v = (View) findViewById(R.id.myView);
Bitmap mybitmap = Bitmap.createBitmap(
v.getChildAt(0).getWidth(),
v.getChildAt(0).getHeight(),
Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(mybitmap);
iv.getChildAt(0).draw(c);
//remember here View may be any view including ScrollView or what ever it may be.
saveBitmap(bitmap);
Hope this will help. Thanks

Merge two bitmap data

For my application, I have create two bitmap as per my requirements.
One for actual image that goes through some image processing and second logo bitmap that only display application logo on top left corner.
Now at saving time I want to combine these bitmaps and want to generate single JPEG file as output.
To accomplish this task I have write following code.
orignalbitmap = orignalbitmap.copy(Config.ARGB_8888, true);
Canvas savedCanvas = new Canvas(orignalbitmap);
savedCanvas.setBitmap(logoBitmap);
savedCanvas.drawBitmap(orignalbitmap, 0, 0, transPaint);
savedCanvas.drawBitmap(logoBitmap, 0, 0, transPaint);
try {
orignalbitmap.compress(CompressFormat.JPEG, 100, new FileOutputStream(new File("/mnt/sdcard/original.jpg")));
} catch (FileNotFoundException e) {
e.printStackTrace();
}
But at present I only got my original image as output not attached with logo. I want image with logo also that data available in logo bitmap. So how to combine both bitmaps data that I can't understand so please provide some guidance in this.

use this function for combine two bitmap in single bitmap
public static Bitmap combineImages(Bitmap c, Bitmap s)
{
Bitmap cs = null;
int width, height = 0;
if(c.getWidth() > s.getWidth()) {
width = c.getWidth() + s.getWidth();
height = c.getHeight();
} else {
width = s.getWidth() + s.getWidth();
height = c.getHeight();
}
cs = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
Canvas comboImage = new Canvas(cs);
comboImage.drawBitmap(c, 0f, 0f, null);
comboImage.drawBitmap(s, c.getWidth(), 0f, null);
return cs;
}

In Android, why is my combined bitmap blank?

I'm working with a set of layered images (think stacked) and I need to combine them into one element.
I'm basing my solution off Combine multiple bitmap into one
//send a map to the method that has my stored image locations in order
private Bitmap combineImageIntoOne(NavigableMap<Integer, String> layerImages) {
//size of my bitmaps
int w = 400, h = 400;
//bitmap placeholder
Bitmap productIndex = null;
//flattened layers
Bitmap temp = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
//canvas to write layers to
Canvas canvas = new Canvas(temp);
int top = 0;
for (Map.Entry<Integer, String> e : layerImages.entrySet()) {
//create the layer bitmap
productIndex = decodeSampledBitmapFromResource(getResources(), e.getValue(), 400, 400);
//add layer to canvas
canvas.drawBitmap(productIndex, 0f, top, null);
}
//convert temp to a BitmapDrawable
Drawable d = new BitmapDrawable(getResources(),temp);
//set my image view to have the flattened image
carBase.setImageDrawable(d);
return temp;
}
The decodeSampledBitmapFromResource come from the Android docs about loading large bitmaps: Loading Large Bitmaps Efficiently You can review the code on that doc to see what I"m doing. I didn't edit the Android code much.
I've been using the Android code just fine to add layers to the FrameLayout but ended up running out of memory when the layers starting getting pretty high in number. This combining method is being used to conserve memory space.
Any ideas why the final bitmap doesn't have any content?

Reference LINK <-------------------------
public Bitmap combineImages(Bitmap c, Bitmap s) { // can add a 3rd parameter 'String loc' if you want to save the new image - left some code to do that at the bottom
Bitmap cs = null;
int width, height = 0;
if(c.getWidth() > s.getWidth()) {
width = c.getWidth() + s.getWidth();
height = c.getHeight();
} else {
width = s.getWidth() + s.getWidth();
height = c.getHeight();
}
cs = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
Canvas comboImage = new Canvas(cs);
comboImage.drawBitmap(c, 0f, 0f, null);
comboImage.drawBitmap(s, c.getWidth(), 0f, null);
// this is an extra bit I added, just incase you want to save the new image somewhere and then return the location
/*String tmpImg = String.valueOf(System.currentTimeMillis()) + ".png";
OutputStream os = null;
try {
os = new FileOutputStream(loc + tmpImg);
cs.compress(CompressFormat.PNG, 100, os);
} catch(IOException e) {
Log.e("combineImages", "problem combining images", e);
}*/
return cs;
}

Bitmap.getPixel only returning 0

I have the following code for creating a bitmap:
public PixelMapper(Path inputPath){
RectF src = new RectF();
inputPath.computeBounds(src, true);
int width = (int)src.width()+1;
int height = (int)src.height()+1;
largeBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ALPHA_8);
Paint canvasPaint = new Paint();
canvasPaint.setAntiAlias(false);
canvasPaint.setColor(Color.BLACK);
canvasPaint.setStyle(Style.STROKE);
canvasPaint.setStrokeWidth(5);
Canvas canvas = new Canvas(largeBitmap);
canvas.drawPath(inputPath, canvasPaint);
bitmap = Bitmap.createScaledBitmap(largeBitmap, SIDE_OF_BITMAP, SIDE_OF_BITMAP, true);
bitmap = Bitmap.createBitmap(bitmap);//so that a immutable bitmap is created
drawPixelMap();
}
public void drawPixelMap(){
for(int x=0; x<bitmap.getWidth(); x++){
String msg="";
for(int y=0; y<bitmap.getHeight(); y++){
msg = Integer.toHexString( bitmap.getPixel(x,y) );
Log.v("bitmap", msg);
}
}
}
int[] pixels = new int[64];
bitmap.getPixels(pixels, 0, bitmap.getWidth(), 0, 0, SIDE_OF_BITMAP, SIDE_OF_BITMAP);
bitmap.setPixels(pixels, 0, 8, 0, 0, 8, 8);
for ( int pixel : pixels)
Log.v("bitmap", Integer.toHexString(pixel) );
The problem is that all the log messages are "0": both getPixel and getPixels return "0". What is worse is that if I remove the line bitmap.getPixels(...); and leave the bitmap.setPixels(...) line,the image is still drawn as before. It seems that the bitmap variable is just a reference and a bitmap doesn't exist, and for some reason, I am unable to get those pixels.
I know the bitmap is created as required as I am able to view it on a ImageView. It shows black and white pixels with a few grey ones too. Code:
Bitmap newBitmap = Bitmap.createScaledBitmap(bitmap, 128, 128, false);
imageView1.setImageBitmap(newBitmap);
The SIDE_OF_BITMAP = 8, all classes (Path, Bitmap, Canvas) are of android.
I tried saving the bitmap to file with the following code:
public String saveToStorage(String fileName){
if( !storageDir.exists() )
storageDir.mkdirs();
File file = new File(storageDir, fileName + ".png");
try{
OutputStream out = new FileOutputStream(file);
boolean result = bitmap.compress(CompressFormat.PNG, 100, out);
out.close();
return Boolean.toString(result);
}
catch (FileNotFoundException e){
Log.e("save", "cannot save file", e);
return "File not found exception";
}
catch (IOException e){
Log.e("save", "IO error", e);
return "IO Exception";
}
}
but it returns "false" i.e. the bitmap.compress method returns false. Please give me any help at all, not necessarily sample code.

I found my mistake. It lies in the line
largeBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ALPHA_8);
The Bitmap.Config.ALPHA_8 only creates a mask. It does not create actual pixels. That is why I was getting the erroneous results. However, when I was setting it to a ImageView I was getting the required result because its background (by default) is white.
I solved my problem by changing the Bitmap.Config.ALPHA_8 to Bitmap.Config.ARGB_8888

The line
bitmap = Bitmap.createBitmap(bitmap);
creates a immutable bitmap of the same dimension/color depth, etc as the source bitmap, but not converting the source bitmap from mutable to immutable. So your new bitmap is blank.
You can first create a immutable bitmap using newBitmap = Bitmap.createBitmap(int[], int, int, Bitmap.Config), then create a canvas for it by canvas = new Canvas(newBitmap). Your bitmap can now be copied to newBitmap by canvas.drawBitmap(bitmap, 0, 0, null).

Android merge two images

I have these two images, which I basically merge on canvas. Now i want to save that canvas into an image. How should i do it or if there is any other way to merge two images.
My sample code is -
Bitmap bmp1 = BitmapFactory.decodeResource(getResources(),
R.drawable.duckpic);
Bitmap bmp2 = BitmapFactory.decodeResource(getResources(),
R.drawable.img);
// canvas.drawColor(Color.BLACK);
// canvas.drawBitmap(_scratch, 10, 10, null);
Bitmap bmOverlay = Bitmap.createBitmap(bmp2.getWidth(), bmp2
.getHeight(), bmp2.getConfig());
// Canvas cs = new Canvas(bmp2);
canvas.scale((float) 0.5, (float) 0.5);
canvas.drawBitmap(bmp2, new Matrix(), null);
canvas.drawBitmap(bmp1, new Matrix(), null);
canvas.save();
I got it working by doing this -
cs = Bitmap.createBitmap(c.getWidth(), c.getHeight(), Bitmap.Config.ARGB_8888);
Canvas comboImage = new Canvas(cs);
comboImage.drawBitmap(s, new Matrix(), null);
comboImage.drawBitmap(c, new Matrix(), null);
comboImage.save();
// this is an extra bit I added, just incase you want to save the new
// image somewhere and then return the location
String tmpImg = String.valueOf(System.currentTimeMillis()) + ".png";
OutputStream os = null;
try {
os = new FileOutputStream("/sdcard/" + tmpImg);
cs.compress(CompressFormat.PNG, 100, os);
} catch (IOException e) {
Log.e("combineImages", "problem combining images", e);
}
Basically it is given here - http://www.jondev.net/articles/Combining_2_Images_in_Android_using_Canvas

Use canvas.setBitmap(Bitmap bitmap). This will send the canvas to the specified Bitmap. You'll want to create a new, mutable bitmap for this. After you call setBitmap you can then save that Bitmap to a file.