Develop Reference

How do i correctly convert a integer back to Bitmap

In Android Studio I can use the following lines of code to get an array from Bitmap
Bitmap bitmap = get_Image();
Bitmap resizeBitmap = getResizedBitmap(bitmap);
int[] iArr = new int[(resizeBitmap.getWidth() * resizeBitmap.getHeight())];
resizeBitmap.getPixels(iArr, 0, resizeBitmap.getWidth(), 0, 0, resizeBitmap.getWidth(), resizeBitmap.getHeight());
Here is the resizer function:
public Bitmap getResizedBitmap(Bitmap bitmap) {
if (576 == bitmap.getWidth() && 1024 == bitmap.getHeight()) {
return bitmap;
}
Bitmap createBitmap = Bitmap.createBitmap(576, 1024, Config.RGB_565);
Matrix scaledMatrix = scaledMatrix(bitmap.getWidth(), bitmap.getHeight(), createBitmap.getWidth(), createBitmap.getHeight());
new Canvas(createBitmap).drawBitmap(bitmap, scaledMatrix, null);
return createBitmap;
}
However when I convert that int array back to bitmap the image is wrong
Bitmap bmp = Bitmap.createBitmap(1024, 576, Config.RGB_565);
bmp.setPixels(iArr, 0, 1024, 0, 0, 1024, 576);
textViewToChange.setText("Bitmap created");
This is the image when i save it to a file or display it https://imgur.com/a/ZQ0DJAy The above image is how it looks like and below is how it should had looked like
If i read the incorrect image in python, the RGB pixels are placed exactly where they should be like in the correct image but the image dosen't look the same. Why? How can i fix this?

Rotate a bitmap using render script android

When I use following code, it ends up with outofmemory exception. After doing researh Render script looks like a good candidate. Where can I find sample code for similar operation and how can integrate it to my project.
public Bitmap rotateBitmap(Bitmap image, int angle) {
if (image != null) {
Matrix matrix = new Matrix();
matrix.postRotate(angle, (image.getWidth()) / 2,
(image.getHeight()) / 2);
return Bitmap.createBitmap(image, 0, 0, image.getWidth(),
image.getHeight(), matrix, true);
}
return null;
}

Basically rotating bitmap is a task of rotating 2D array without using additional memory. And this is the correct implementation with RenderScript: Android: rotate image without loading it to memory .
But this is not necessary if all you want is just to display rotated Bitmap. You can simply extend ImageView and rotate the Canvas while drawing on it:
canvas.save();
canvas.rotate(angle, X + (imageW / 2), Y + (imageH / 2));
canvas.drawBitmap(imageBmp, X, Y, null);
canvas.restore();
What about ScriptIntrinsic, since it's just a built-in RenderScript kernels for common operations you cannot do nothing above the already implemented functions: ScriptIntrinsic3DLUT, ScriptIntrinsicBLAS, ScriptIntrinsicBlend, ScriptIntrinsicBlur, ScriptIntrinsicColorMatrix, ScriptIntrinsicConvolve3x3, ScriptIntrinsicConvolve5x5, ScriptIntrinsicHistogram, ScriptIntrinsicLUT, ScriptIntrinsicResize, ScriptIntrinsicYuvToRGB. They do not include functionality to rotate bitmap at the moment so you should create your own ScriptC script.

Try this code..
private Bitmap RotateImage(Bitmap _bitmap, int angle) {
Matrix matrix = new Matrix();
matrix.postRotate(angle);
_bitmap = Bitmap.createBitmap(_bitmap, 0, 0, _bitmap.getWidth(), _bitmap.getHeight(), matrix, true);
return _bitmap;
}
Use this code when select image from gallery.
like this..
File _file = new File(file_name);
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 1;
Bitmap bitmap = BitmapFactory.decodeFile(file_name, options);
try {
ExifInterface exif = new ExifInterface(file_name);
int orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, 1);
if (orientation == ExifInterface.ORIENTATION_ROTATE_90) {
bitmap = RotateImage(bitmap, 90);
} else if (orientation ==ExifInterface.ORIENTATION_ROTATE_270) {
bitmap = RotateImage(bitmap, 270);
}
} catch (Exception e) {
e.printStackTrace();
}
image_holder.setImageBitmap(bitmap);

Bitmap size exceed VM budget

I have read those posts on this issue but my case is abit different as I am NOT DISPLAYING the bitmap but just post-processing the image from raw data.
First, I call ImageProcessing.rgbToBitmap(data,width, height); which will return a Bitmap object. Then I perform these 3 functions SEPARATELY.
Rotate Bitmap
Add a watermark overlay to Bitmap
Add date at lower right hand corner of Bitmap
All 3 methods called will create an return a Bitmap object which probably causes the crash as I am trying to save an image every 1000ms! Sometimes the images saved are distorted probably due to the memory error.
I am posting my codes below and any advices are greatly appreciated. I do not want to compromise on the quality on the image taken though. (Need to preserve the resolution)
public static Bitmap addWatermark(Resources res, Bitmap source) {
int w, h;
Canvas c;
Paint paint;
Bitmap bmp, watermark;
Matrix matrix;
float scale;
RectF r;
w = source.getWidth();
h = source.getHeight();
// Create the new bitmap
bmp = Bitmap.createBitmap(w, h, Bitmap.Config.RGB_565);
paint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.DITHER_FLAG
| Paint.FILTER_BITMAP_FLAG);
// Copy the original bitmap into the new one
c = new Canvas(bmp);
c.drawBitmap(source, 0, 0, paint);
// Load the watermark
watermark = BitmapFactory.decodeResource(res, R.drawable.watermark);
// Scale the watermark to be approximately 10% of the source image
// height
scale = (float) (((float) h * 0.80) / (float) watermark.getHeight());
// Create the matrix
matrix = new Matrix();
matrix.postScale(scale, scale);
// Determine the post-scaled size of the watermark
r = new RectF(0, 0, watermark.getWidth(), watermark.getHeight());
matrix.mapRect(r);
// Center watermark
matrix.postTranslate((w - r.width()) / 2, (h - r.height()) / 2);
// Draw the watermark
c.drawBitmap(watermark, matrix, paint);
// Free up the bitmap memory
watermark.recycle();
return bmp;
}
public static Bitmap addDate(Bitmap src, String date) {
int w = src.getWidth();
int h = src.getHeight();
//Bitmap result = Bitmap.createBitmap(w, h, src.getConfig());
Bitmap result = src;
Canvas canvas = new Canvas(result);
canvas.drawBitmap(src, 0, 0, null);
Paint paint = new Paint();
paint.setColor(Color.rgb(255, 185, 15));
paint.setTextSize(20);
paint.setAntiAlias(true);
canvas.drawText(date, w - 200, h - 20, paint);
return result;
}
public static Bitmap rotate(Bitmap src, int rotation) {
int width = src.getWidth();
int height = src.getHeight();
// create a matrix for the manipulation
Matrix matrix = new Matrix();
// rotate the Bitmap
matrix.postRotate(rotation);
// recreate the new Bitmap, swap width and height and apply
// transform
Bitmap rotatedBitmap = Bitmap.createBitmap(src, 0, 0, width, height,
matrix, true);
return rotatedBitmap;
}

Try this first:
Change
// Copy the original bitmap into the new one
c = new Canvas(bmp);
c.drawBitmap(source, 0, 0, paint);
with
// Copy the original bitmap into the new one
c = new Canvas(bmp);
bmp.recycle(); //here or below
c.drawBitmap(source, 0, 0, paint);
//below bmp.recycle();
and here:
canvas.drawText(date, w - 200, h - 20, paint);
return result;
with
canvas.drawText(date, w - 200, h - 20, paint);
result.recycle();
return result;
and here
Bitmap rotatedBitmap = Bitmap.createBitmap(src, 0, 0, width, height,
matrix, true);
return rotatedBitmap;
with
Bitmap rotatedBitmap = Bitmap.createBitmap(src, 0, 0, width, height,
matrix, true);
return rotatedBitmap;
rotatedBitmap.recycle();
Add all this (recycle();) maybe this is already enough and also try the code with smaller bitmaps, en see if it still crashes (like 50px by 50px).
And no, their is no way to increase the VM of your phone.

Recycled bitmap exception

I'm getting this exception:
Exception: java.lang.IllegalStateException: Can't copy a recycled bitmap
My code is:
int width = bitmap.getWidth();
int height = bitmap.getHeight();
int newWidth;
int newHeight;
if (width >= height) {
newWidth = Math.min(width,1024);
newHeight = (int) (((float)newWidth)*height/width);
}
else {
newHeight = Math.min(height, 1024);
newWidth = (int) (((float)newHeight)*width/height);
}
float scaleWidth = ((float)newWidth)/width;
float scaleHeight = ((float)newHeight)/height;
Matrix matrix = new Matrix();
matrix.postScale(scaleWidth, scaleHeight);
switch (orientation) {
case 3:
matrix.postRotate(180);
break;
case 6:
matrix.postRotate(90);
break;
case 8:
matrix.postRotate(270);
break;
}
Bitmap resizedBitmap = Bitmap.createBitmap(bitmap, 0, 0, width, height, matrix, true);
bitmap.recycle();
try {
bitmap = resizedBitmap.copy(resizedBitmap.getConfig(), true);
}
catch (Exception e) {
Log.v(TAG,"Exception: "+e);
}
If the exception is telling me that I've recycled resizedBitmap, that is patently false! What am I doing wrong??

You are actually calling bitmap.recycle(); after this line:
Bitmap resizedBitmap = Bitmap.createBitmap(bitmap, 0, 0, width, height, matrix, true);

Quote from Bitmap.createBitmap() method's Javadoc:
Returns an immutable bitmap from subset of the source bitmap, transformed by the optional matrix. The new bitmap may be the same object as source, or a copy may have been made. It is initialized with the same density as the original bitmap. If the source bitmap is immutable and the requested subset is the same as the source bitmap itself, then the source bitmap is returned and no new bitmap is created.
That mean that in some cases, i.e. when asking to resize a source bitmap to its actual size, there will be no difference between source and resized bitmap. To save memory the method will just return the same instance of bitmap.
To fix your code you should check whether a new bitmap has been created:
Bitmap resizedBitmap = Bitmap.createBitmap(sourceBitmap, 0, 0, width, height, matrix, true);
if (resizedBitmap != sourceBitmap) {
sourceBitmap.recycle();
}

Android rotate bitmap 90 degrees results in squashed image. Need a true rotate between portrait and landscape

I am trying to rotate a bitmap image 90 degrees to change it from a landscape format to a portrait format. Example:
[a, b, c, d]
[e, f, g, h]
[i, j, k, l]
rotated 90 degree clockwise becomes
[i,e,a]
[j,f,b]
[k,g,c]
[l,h,d]
Using the code below (from an online example) the image is rotated 90 degrees but retains the landscape aspect ratio so you end up with a vertically squashed image. Am I doing something wrong? Is there another method I need to use? I am also willing to rotate the jpeg file that I'm using to create the bitmap if that is easier.
// create a matrix for the manipulation
Matrix matrix = new Matrix();
// resize the bit map
matrix.postScale(scaleWidth, scaleHeight);
// rotate the Bitmap
matrix.postRotate(90);
// recreate the new Bitmap
Bitmap resizedBitmap = Bitmap.createBitmap(bitmapOriginal, 0, 0, widthOriginal, heightOriginal, matrix, true);

This is all you need to rotate the image:
Matrix matrix = new Matrix();
matrix.postRotate(90);
rotated = Bitmap.createBitmap(original, 0, 0,
original.getWidth(), original.getHeight(),
matrix, true);
In your code sample, you included a call to postScale. Could that be the reason your image is being stretched? Perhaps take that one out and do some more testing.

Here's how you would rotate it properly (this insures proper rotation of the image)
public static Bitmap rotate(Bitmap b, int degrees) {
if (degrees != 0 && b != null) {
Matrix m = new Matrix();
m.setRotate(degrees, (float) b.getWidth() / 2, (float) b.getHeight() / 2);
try {
Bitmap b2 = Bitmap.createBitmap(
b, 0, 0, b.getWidth(), b.getHeight(), m, true);
if (b != b2) {
b.recycle();
b = b2;
}
} catch (OutOfMemoryError ex) {
throw ex;
}
}
return b;
}

This code worked great for me:
Matrix matrix = new Matrix();
matrix.setRotate(90, 0, 0);
matrix.postTranslate(original.getHeight(), 0);
rotatedBitmap = Bitmap.createBitmap(newWidth, newHeight, original.getConfig());
Canvas tmpCanvas = new Canvas(rotatedBitmap);
tmpCanvas.drawBitmap(original, matrix, null);
tmpCanvas.setBitmap(null);

check the canvas size where you draw the bitmap, maybe your canvas is still landscape, so only the square part of the rotated bitmap could be seen.