I have a bitmap taken from a camera. I want to crop the image so it only leaves the bottom portion of it. The cropped image should be 80% less the height of the original bitmap, so I want only the 20% of the bottom part starting from the left edge.
I'm doing this explicitly in the code without any Android cropping intent whatsoever.
An image to visualize what I want to achieve:
I've managed to crop the top part of the bitmap by using this code:
final Bitmap toBeCropped = BitmapFactory.decodeFile(mFile.getPath());
final BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();
bitmapOptions.inTargetDensity = 1;
toBeCropped.setDensity(Bitmap.DENSITY_NONE);
int fromHere = (int) (toBeCropped.getHeight() * 0.2);
Bitmap croppedBitmap = Bitmap.createBitmap(toBeCropped, 0, 0, toBeCropped.getWidth(), fromHere);
mPreviewHalf.setImageBitmap(croppedBitmap);
But I couldn't find a way to start the cropping 80% from the top. I'm thinking of getting the y-coordinate of the Bitmap, so that I could crop any image sizes and always get the bottom portion only. But can anyone point to me how do I get this coordinate from a bitmap? Or do I have to take it from the layout itself?
I am not familiar with operations on Bitmaps but from inspecting your code and looking at the API my guess would be that you need to specify the y coordinates on the following line to match the starting point:
Bitmap croppedBitmap = Bitmap.createBitmap(toBeCropped, 0, "here", toBeCropped.getWidth(), fromHere);
So my guess would be something like the following:
Bitmap croppedBitmap = Bitmap.createBitmap(toBeCropped, 0, (toBeCropped.getHeight() * 0.8), toBeCropped.getWidth(), fromHere);
in this case fromHere will define the number of rows you want to crop not the starting point (which is 20% of the total as you have pointed out)
This is how I do it:
topcutoff is what you want to cut of on top of the image and buttomcutoff on the buttom (if needed)
height = height - topcutoff;
height = height - bottomcutoff;
croppedBitmap = Bitmap.createBitmap(croppedBitmap, 0, topcutoff, width, height);
Basically you just set a startpoint (topcutoff) from where to begin displaying the bitmap. In your case this would be the position after 80% of your bitmap.
This might also explain some things: Google Bitmap Documentation
"int: The y coordinate of the first pixel in source", so where you want to begin displaying your image.
Related
Using MikeOrtiz's awesome ImageView implementation with touch and zoom events, I wanted to crop a picture taken with the camera to match the zoom. Using his method...
// Return a Rect representing the zoomed image.
RectF getZoomedRect();
...I tried cropping the resulting picture bitmap to the zoom size like so:
RectF zoomCoordinates = mTouchImageView.getZoomedRect();
Bitmap croppedBitmapToOverview = Bitmap.createBitmap(
AppResources.sCurrentImage,
((int) zoomCoordinates.left),
((int) zoomCoordinates.top),
((int) zoomCoordinates.width()),
((int) zoomCoordinates.height()));
However I get a "must be bigger than 0" error with this. While debugging I noticed ALL values were 0 due to casting to an Integer. The real values however go something like this:
//Log.d print for each of those fields without the int cast
Left 0.34047672
Top 0.20797288
Width 0.33333334
Height 0.3429547
So there's my problem, but I can't see how to fix this. I've never worked with bitmaps before or canvas, Rect, etc.
Is there some tweaking I could do to these values, or should I take a different approach altogether?
Got around the problem by simply taking a "screenshot" of the View of sorts. This got me a Bitmap with the picture as it was zoomed
mTouchImageView.setDrawingCacheEnabled(true);
AppResources.sCurrentImage = Bitmap.createBitmap(mTouchImageView.getDrawingCache());
multiply the coordinates with the size of your image like
(int)(zoomCoordinates.left * imageSize)
I'm currently loading an image that can be either landscape or portrait.
I'm then wanting to resize the bitmap to draw directly onto a canvas for a full screen image.
I need keep the aspect ratio but have the image not fit to the screen but crop off any image that's bigger than the screen.
I can resize it and fit it to the screen with the following:
Matrix m = new Matrix();
m.setRectToRect(new RectF(0, 0, b.getWidth(), b.getHeight()), new RectF(0, 0, MyWallpaperService.this.width, MyWallpaperService.this.height), Matrix.ScaleToFit.CENTER);
b = Bitmap.createBitmap(b, 0, 0, b.getWidth(), b.getHeight(), m, true);
but I don't want to have the black bars at the top/bottom or sides, but I can't think of the routine to resize correctly for this.
As you are drawing the image onto the canvas yourself the first step is to calculate the dimensions required for the final image based on the screen size and the original image aspect ratio.
Then use the static function createScaledBitmap from the Bitmap class to resize your bitmap to match the calculated dimensions. Make sure you only call this function once and store the bitmap for use in the drawing routine.
Finally draw the bitmap so only the area of the bitmap you want to see is on the screen.
A more memory friendly approach is to add another step to crop the image using Bitmap.createBitmap before calling Bitmap.createScaledBitmap. This reduces the chance of encountering memory issues caused by the user selecting a source image that is thin and long.
It seems that setting a wallpaper on Android just doesn't work in any useful way.
If you get an image from your phone and set it as the wallpaper, it's way too big for the screen
If you resize it (either using a createBitmap() function that allows you to specify size, or the ridiculously useless createScaledBitmap()) it goes all jaggy and out of focus
If you use some freaky hacks to fix the quality of the image, it's better, but still not perfectly clear by any stretch.
If you attempt to get the current wallpaper and set that, it still seems to make it too big. It appears to give you the original image file, forcing you to resize it, which doesn't work.
Now, the phone's internal software is perfectly capable of resizing an image to be smaller with no reduction of quality. Why does it not share this functionality?
WallpaperManager wallpaperManager = WallpaperManager.getInstance(Spinnerz.this);
// gets the image from file, inexplicably upside down.
Bitmap bitmap = BitmapFactory.decodeFile(Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator + "DCIM/Camera/Zedz.jpg");
// use some rotation to get it on an angle that matches the screen.
Matrix bitmapTransforms = new Matrix();
bitmapTransforms.setRotate(90); // flip back upright
bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(),bitmapTransforms, false); // create bitmap from bitmap from file, using the rotate matrix
// lets set it exactly to the resolution of my Samsung Galaxy S2: 480x800 pixels.
// This function appears to exist specifically to scale a bitmap object - should do a good job of it!
bitmap = Bitmap.createScaledBitmap(bitmap, 480, 800, false);
wallpaperManager.setBitmap(bitmap);
// result is quite a jaggy image - not suitable as a wallpaper.
PIC:
Try this ,
Display d = ((WindowManager)getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
int width = d.getWidth();
int height = d.getHeight();
I usually download images that are larger in size and shrink them using an imageview but lately Im trying to deal with my apps not working on a lesser network connection so I was wondering how can I increase the size of an image once it gets to the device. I tried resizing the image once it was in an imageview but the imageview will get no larger than the original image. Im sure theres a really easy way to increase or blow up an image on the device but I havent come across it yet.
So.....how can I increase the size of an image. Id like to blow it up and use it in an imageview but the images Im dealing with are only 128X256 and Id like to expand them to about 512X1024.
Try using this method:
public static Bitmap scaleBitmap(Bitmap bitmapToScale, float newWidth, float newHeight) {
if(bitmapToScale == null)
return null;
//get the original width and height
int width = bitmapToScale.getWidth();
int height = bitmapToScale.getHeight();
// create a matrix for the manipulation
Matrix matrix = new Matrix();
// resize the bit map
matrix.postScale(newWidth / width, newHeight / height);
// recreate the new Bitmap and set it back
return Bitmap.createBitmap(bitmapToScale, 0, 0, bitmapToScale.getWidth(), bitmapToScale.getHeight(), matrix, true); }
refer to my answer in: ImageView OutofMemoryException
Use matrix to resize the bitmap.
Check this
Resize Bitmap
If you want to scale the Bitmap manually, there is a Bitmap.createScaledBitmap() method that you can use for this.
If you want the ImageView to handle this, you have to set the layout_width/layout_height to something other than wrap_content or it will always shrink to the size of the Bitmap. Then you need to change the scaleType attribute to a type that actually scales the bitmap.
The functionality to scale image up or down is readily available via android.graphics library:
Bitmap bitmapScaled = Bitmap.createScaledBitmap(Bitmap bitmapOrig, int widthNew, int heightNew, boolean filter);
I want to crop Red part from following image, Is there any simple method available in android that can crop following image.
I have found many SO questions but all are suggesting to used following code:
Bitmap croppedBitmap = Bitmap.createBitmap(bitmapOriginal, 100, 100,100, 100);
This code work well if width & height are around 2MP resolution, but if that cropped part is more than 3MP resolution than application got crashed with OOM error.
Is there any way that handle image more than 3MP during cropping?
You can used following code that can solve your problem.
Matrix matrix = new Matrix();
matrix.postScale(0.5f, 0.5f);
Bitmap croppedBitmap = Bitmap.createBitmap(bitmapOriginal, 100, 100,100, 100, matrix, true);
Above method do postScalling of image before cropping, so you can get best result with cropped image without getting OOM error.
For more detail you can refer this blog
1- Change your imageview for bitmap
final Bitmap bitmap=BitmapFactory.decodeResource(getResources(), R.drawable.img);
2-use your bitmap to crop what you want
Bitmap croppedBmp = Bitmap.createBitmap(bitmap, x, y , width , height);
3-Take care x,y from Top and left
4- to preview your bitmap again in your imageview
imageView.setImageBitmap(croppedBmp);
If you want to crop image in any shape OR only selected part then
you can use ready made open source library