Loading a resource to a mutable bitmap - android

I am loading a bitmap from a resource like so:
Bitmap mBackground = BitmapFactory.decodeResource(res,R.drawable.image);
What I want to do is make some changes to the bitmap before It gets drawn to the main canvas in my draw method (As it would seem wasteful to repeat lots of drawing in my main loop when it isn't going to change). I am making the changes to the bitmap with the following:
Canvas c = new Canvas(mBackground);
c.drawARGB(...); // etc
So naturally I get an exception
java.lang.IllegalStateException: Immutable bitmap passed to Canvas constructor
So to avoid that I made a copy of the bitmap so that it is mutable
Bitmap mBackground = BitmapFactory.decodeResource(res,R.drawable.image).copy(Bitmap.Config.ARGB_8888, true);
Which avoid the problem however it sometimes causes OutOfMemoryExceptions, do know any better ways of achieving what I want?

Use decodeResource(Resources res, int id, BitmapFactory.Options opts) and specify inMutable in the options.
http://developer.android.com/reference/android/graphics/BitmapFactory.html

You'd better use RapidDecoder.
import rapid.decoder.BitmapDecoder;
Bitmap mBackground = BitmapDecoder.from(res, R.drawable.image)
.mutable().decode();
Works for API level 8.

Instad of yours:
Bitmap mBackground = BitmapFactory.decodeResource(res,R.drawable.image);
Use:
BitmapFactory.Options options = new BitmapFactory.Options();
options.inMutable = true;
Bitmap mBackground = BitmapFactory.decodeResource(res,R.drawable.image, options);

Related

Adding text on top of an image using a Canvas - Android

I want to add some text on top of an image.
I read the image from the sd card and set it to a Bitmap variable.
Bitmap myBitmap = BitmapFactory.decodeFile(imgFile.getAbsolutePath());
Then I added it to a canvas. The code I used is given below,
Canvas c = new Canvas(myBitmap);
But when I added this line, the app crashed at that point. Why is it and how can i solve this ??
Note : Above mention code lines are inside onActivityResult method.
You app crash because your
BitmapFactory.decodeFile
return a immutable bitmap and public Canvas (Bitmap bitmap) only accept a mutable bitmap.
To solve your problem you must convert your immutable Bitmap into mutable see here the method
If you target only >= API 11 , you can use
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inMutable = true;
Bitmap myBitmap = BitmapFactory.decodeFile(imgFile.getAbsolutePath(), options);

Color Banding Android Solution

What is possible solution to banded images in Android Activity or in OpenGl.
Look at the answer below.
Hope it Helps
Color Banding Solved ooooooooooyyyyyyyeaaaaaaaaaa
I solved color banding in two phases
1) * when we use the BitmapFactory to decode resources it decodes the resource in RGB565 which shows color banding, instead of using ARGB_8888, so i used BitmapFactory.Options for setting the decode options to ARGB_8888
second problem was whenever i scaled the bitmap it again got banded
2) This was the tough part and took a lot of searching and finally worked
* the method Bitmap.createScaledBitmap for scaling bitmaps also reduced the images to RGB565 format after scaling i got banded images(the old method for solving this was using at least one transparent pixel in a png but no other format like jpg or bmp worked)so here i created a method CreateScaledBitmap to scale the bitmap with the original bitmaps configurations in the resulting scale bitmap(actually i copied the method from a post by logicnet.dk and translated in java)
BitmapFactory.Options myOptions = new BitmapFactory.Options();
myOptions.inDither = true;
myOptions.inScaled = false;
myOptions.inPreferredConfig = Bitmap.Config.ARGB_8888;//important
//myOptions.inDither = false;
myOptions.inPurgeable = true;
Bitmap tempImage =
BitmapFactory.decodeResource(getResources(),R.drawable.defaultart, myOptions);//important
//this is important part new scale method created by someone else
tempImage = CreateScaledBitmap(tempImage,300,300,false);
ImageView v = (ImageView)findViewById(R.id.imageView1);
v.setImageBitmap(tempImage);
// the function
public static Bitmap CreateScaledBitmap(Bitmap src, int dstWidth, int dstHeight, boolean filter)
{
Matrix m = new Matrix();
m.setScale(dstWidth / (float)src.getWidth(), dstHeight / (float)src.getHeight());
Bitmap result = Bitmap.createBitmap(dstWidth, dstHeight, src.getConfig());
Canvas canvas = new Canvas(result);
//using (var canvas = new Canvas(result))
{
Paint paint = new Paint();
paint.setFilterBitmap(filter);
canvas.drawBitmap(src, m, paint);
}
return result;
}
Please correct me if i am wrong.
Also comment if it worked for you.
I am so happy i solved it, Hope it works for you All.
For OpenGl you simply bind the bitmap created after applying upper functions

How to use high-quality rendering for an Android resource bitmap loaded into an OpenGL texture?

I know very little about OpenGL so please be gentle.
The app needs to load a bitmap (from resources), resize it, and use it in an OpenGL texture. I have an implementation that works, but there was a bad banding issue on the Wildfire S. So I changed the implementation and fixed the banding issue (by switching to ARGB_8888) but that then broke the functionality on the Galaxy Nexus and the Nexus One.
I am seeing three visual presentations:
The bitmap (a smooth 24-bit gradient) shows correctly, with no banding.
The gradient shows, but with obvious banding
The texture shows as flat white, no bitmap (or issues in logcat)
Here are two versions of the method to load the bitmap, and notes on the results seen with each:
// White on Galaxy Nexus. White on Nexus One. Renders correct image (no banding) on Wildfire S
private Bitmap getBitmap1() {
BitmapFactory.Options options = new BitmapFactory.Options();
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
options.outWidth = getTextureSize();
options.outHeight = getTextureSize();
final Bitmap bmp;
bmp = BitmapFactory.decodeResource(getResources(), bitmapResourceId, options);
return bmp;
}
// Renders correctly (no banding) on Galaxy Nexus. Renders on Nexus One and Wildfire S but with obvious banding.
private Bitmap getBitmap2() {
int textureSize = getTextureSize();
BitmapFactory.Options options = new BitmapFactory.Options();
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
options.outWidth = getTextureSize();
options.outHeight = getTextureSize();
final Bitmap bmp;
bmp = Bitmap.createScaledBitmap(BitmapFactory.decodeResource(getResources(), bitmapResourceId, options), textureSize, textureSize, true);
return bmp;
}
getTextureSize() returns 1024.
How do I build a single method that shows the bitmap without banding on all devices, and without any devices show a big white box?
getBitmap1
outHeight and outWidth are used in conjunction with inJustDecodeBounds. You cannot use them to load a scaled bitmap. So the reason you are seeing a white texture is that the bitmap is not a power of two.
getBitmap2
you should keep a reference to the bitmap returned by decodeResource so that you can recycle it later.
also use options.inScaled = false;to load an unscaled version of the bitmap. Also take note that createScaledBitmap may change the depth of the bitmap to RGB_565 if the original bitmap contains no alpha channel (Source);
Questions:
is the original Bitmap Resource square? If not your scaling code will change the aspect ratio which could result in artifacts.
EDIT:
so how do you scale a bitmap and preserve the bit depths?
Easiest solution is to pass a bitmap with alpha channel into createScaledBitmap.
You can also scale yourself like so:
Bitmap newBitmap = Bitmap.createBitmap(1024, 1024, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(newBitmap);
final int width = src.getWidth();
final int height = src.getHeight();
final float sx = 1024 / (float)width;
final float sy = 1024 / (float)height;
Matrix m = new Matrix();
m.setScale(sx, sy);
canvas.drawBitmap(src,m,null );
src.recycle();
ANOTHER EDIT:
take a look at this Question for pointers on how to deal with that.
OpenGL.org has this to say about that error:
GL_INVALID_VALUE​, 0x0501: Given when a value parameter is not a leval
value for that function. This is only given for local problems; if the
spec allows the value in certain circumstances, and other parameters
or state dictate those circumstances, then GL_INVALID_OPERATION is the
result instead.
Step one is to find the exact opengl call that is causing the problem. You'll have to do trial and error to see which line is throwing that error. If you set up the program flow like this:
glSomeCallA()
glGetError() //returns 0
glSomeCallB()
glGetError() //returns 0
glSomeCallC()
glGetError() //returns 0x501
Then you'll know that glSomeCallC was the operation that caused the error. If you look at the man page for that particular call, it will enumerate everything that could cause a specific error to occur.
In your case I'll guess that the error will be after glTexImage call just to save you some time, though I'm not positive.
If you look at the glTexImage man page, at the bottom it will list everything that can cause an invalid value error. My guess will be that your texture is larger than the GL_MAX_TEXTURE_SIZE. You can confirm this by checking glGetIntegerv(GL_MAX_TEXTURE_SIZE);
Color Banding Solved ooooooooooyyyyyyyeaaaaaaaaaa
I solved color banding in two phases
1) * when we use the BitmapFactory to decode resources it decodes the resource in RGB565 which shows color banding, instead of using ARGB_8888, so i used BitmapFactory.Options for setting the decode options to ARGB_8888
second problem was whenever i scaled the bitmap it again got banded
2) This was the tough part and took a lot of searching and finally worked
* the method Bitmap.createScaledBitmap for scaling bitmaps also reduced the images to RGB565 format after scaling i got banded images(the old method for solving this was using at least one transparent pixel in a png but no other format like jpg or bmp worked)so here i created a method CreateScaledBitmap to scale the bitmap with the original bitmaps configurations in the resulting scale bitmap(actually i copied the method from a post by logicnet.dk and translated in java)
BitmapFactory.Options myOptions = new BitmapFactory.Options();
myOptions.inDither = true;
myOptions.inScaled = false;
myOptions.inPreferredConfig = Bitmap.Config.ARGB_8888;//important
//myOptions.inDither = false;
myOptions.inPurgeable = true;
Bitmap tempImage =
BitmapFactory.decodeResource(getResources(),R.drawable.defaultart, myOptions);//important
//this is important part new scale method created by someone else
tempImage = CreateScaledBitmap(tempImage,300,300,false);
ImageView v = (ImageView)findViewById(R.id.imageView1);
v.setImageBitmap(tempImage);
// the function
public static Bitmap CreateScaledBitmap(Bitmap src, int dstWidth, int dstHeight, boolean filter)
{
Matrix m = new Matrix();
m.setScale(dstWidth / (float)src.getWidth(), dstHeight / (float)src.getHeight());
Bitmap result = Bitmap.createBitmap(dstWidth, dstHeight, src.getConfig());
Canvas canvas = new Canvas(result);
//using (var canvas = new Canvas(result))
{
Paint paint = new Paint();
paint.setFilterBitmap(filter);
canvas.drawBitmap(src, m, paint);
}
return result;
}
Please correct me if i am wrong.
Also comment if it worked for you.
I am so happy i solved it, Hope it works for you.

Modifying Bitmap from resources

I'm trying to draw some addition to my ImageView's content, which is represented by Drawable from resources. I know that all Drawables from resources are immutable by default, but even after I call mutable() method and get Bitmap from this Drawable to pass it to Canvas object I get java.lang.IllegalStateException: Immutable bitmap passed to Canvas constructor. Here is the code:
Drawable homeImage = mHomeImage.getBackground(); // my ImageView
homeImage.mutate();
Canvas c = new Canvas(((BitmapDrawable)homeImage).getBitmap());
Is there any way to modify this Bitmap without creating it's copy?
Try this
Bitmap bmp1 = (((BitmapDrawable)homeImage).getBitmap())
.copy(Config.ARGB_8888, true);
Canvas c = new Canvas(bmp1);
You will need to create a new bitmap for the canvas. As the canvas uses the bitmap we pass to store whats drawn, the bitmap should be mutable.

error with setPixels

i am trying to edit images. but i am getting errors with setPixels.
picw = pic.getWidth();
pich = pic.getHeight();
picsize = picw*pich;
int[] pix = new int [picsize];
pic.getPixels(pix, 0, picw, 0, 0, picw, pich);
pic.setPixels(pix,0,pic.getWidth(),0,0,pic.getWidth(),pic.getHeight());
but i am getting illegal state exception with setPixels
Caused by: java.lang.IllegalStateException
at android.graphics.Bitmap.setPixels(Bitmap.java:878)
at com.sandyapps.testapp.testapp.onCreate(testapp.java:66)
I think your Bitmap is not mutable (see setPixel()'s documentation).
If so, create a mutable copy of this Bitmap (using Bitmap.copy(Bitmap.Config config, boolean isMutable) as an example) and work on this one.
It's simple, just use the following command to change it to a mutable Bitmap:
myBitmap = myBitmap.copy( Bitmap.Config.ARGB_8888 , true);
Now the Bitmap myBitmap is replaced by the same Bitmap but this time is mutable
You can also choose another way of storing Pixels (ARGB_8888 etc..):
https://developer.android.com/reference/android/graphics/Bitmap.Config.html
Most probably your pic is immutable. By default, any bitmap created from drawable would be immutable.
If you need to modify an existing bitmap, you should do following:
// Create a bitmap of the same size
Bitmap newBmp = Bitmap.createBitmap(pic.getWidth(), pic.getHeight(), Config.ARGB);
// Create a canvas for new bitmap
Canvas c = new Canvas(newBmp);
// Draw your old bitmap on it.
c.drawBitmap(pic, 0, 0, new Paint());
I had the same problem. Use to fix it:
BitmapFactory.Options opt = new BitmapFactory.Options();
opt.inMutable = true;
Bitmap bitmap = BitmapFactory.decodeResource( getResources(), R.drawable.my_bitmap, opt );
I was facing this problem and finally fixed after long time.
public static void filterApply(Filter filter){
Bitmap bitmcopy = PhotoModel.getInstance().getPhotoCopyBitmap();
//custom scalling is important to apply filter otherwise it will not apply on image
Bitmap scaledBitmap = Bitmap.createScaledBitmap(bitmcopy, bitmcopy.getWidth()-1, bitmcopy.getHeight()-1, false);
filter.processFilter(scaledBitmap);
filterImage.setImageBitmap(scaledBitmap);
}

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