I am using a viewpager to swipe amongst fragments in my app. I define the background in the XML, so
android:background="#drawable/bg_final"
If I use a simple background color, my app works very smooth. If I use it with this background image, fps decreases and my app becomes only passable. It is not slow, just not so smooth, however on weaker devices it could work laggy. Is it a bad way to apply a background image? The whole image is a 480x800 png with the size of 14.7kB. What might be the problem?
(the backgrounds of the fragments are transparent, the viewpager is in a main.xml which has its background with this image)
There are lots of answers out there that point to pre-scaling your bitmap. This is very imporant and you should do it if you can, however after trying several different things, the biggest performance gain I experienced was to create a view and override the onDraw method.
The class could be as simple as this:
public class DTImageView extends View {
public Bitmap imageBitmap;
public DTImageView(Context context) {
super(context);
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if(imageBitmap != null)
canvas.drawBitmap(imageBitmap, 0, 0, null);
}
}
Invoke the code using a prescaled bitmap:
DTImageView bgImageView = new DTImageView(context);
bgImageView.imageBitmap = Bitmap.createScaledBitmap(bitmap,width,height,true);
At this point you can add this view to the view hierarchy where it belongs. In my case, my view hierarchy had a bgImage, a middle ground where all the other functionality happened, and fgImage.
Use the android sdk tool Hierarchy Viewer to profile the app and see how fast each view is taking to draw. My app spent 30-40ms drawing the bgImage and fgImage. Pre-scaling and overriding onDraw reduced that 30-40ms to about 1.5ms.
Here is a screenshot of the Draw performance for one of my views before and after:
BEFORE:
AFTER:
I'm a bit late, but this just bit me, and when running the GPU debugger, I noticed that the system scaled up my image! I had a 1920x1080 image, and it showed up as a 3780x6720 texture!
Ideally, you should have textures for each density in the respective folder (res/drawable-mdpi, res/drawable-hdpi, etc).
However, if you think your one texture is fine, put it into res/drawable-nodpi, not res/drawable. If you put it into res/drawable-nodpi, the system won't scale it up based on the dpi.
In my case, it changed a simple UI from 10fps on a Pixel XL to the full frame rate of 60fps.
I had a background image, not big in size, but with weird dimensions - therefore the stretching and bad performance. I made a method with parameters Context, a View and a drawable ID(int) that will match the device screen size. Use this in e.g a Fragments onCreateView to set the background.
public void setBackground(Context context, View view, int drawableId){
Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(), drawableId);
int width = Resources.getSystem().getDisplayMetrics().widthPixels;
int height = Resources.getSystem().getDisplayMetrics().heightPixels;
bitmap = Bitmap.createScaledBitmap(bitmap, width, height, true);
BitmapDrawable bitmapDrawable = new BitmapDrawable(context.getResources(), bitmap);
view.setBackground(bitmapDrawable);
}
The reason for this could be that the image is being stretched, and Android has performance issues with stretching background images.
Instead, you should either replace the background image with either a background color or see this answer to have the image repeat instead of stretch.
I had the same problem and I resolved it by using this method:
Add your image to the mipmap folder which is located under the res directory. It will add the image according to it's density.
Create add only one background image with size 1080x1920 and put it in drawable-nodpi folder and that solved this problem
Related
I want to dispaly pixelart in an ImageView but it keeps getting blurry.
I tried it like explained in this post (and some others) and I tried it with the function createScaledBitmap like you can see in the code. But it still gets blurry.
What else can I do to show my PixelArt correctly?
var bitmap = Bitmap.createScaledBitmap(fu, 120, 120, false)
var drawable = BitmapDrawable(context.resources, bitmap)
drawable.setAntiAlias(false)
drawable.setFilterBitmap(false)
myImageView.setImageDrawable(drawable )
(The Imageview is inside a RecyclerView but I don't think that that is important for my problem.)
You're scaling the image up before disabling the filtering, so it still looks filtered. It also wastes memory to enlarge a small sprite into a large bitmap.
You don't need to mess with manual scaling like that. You can set the drawable on you ImageView (either assign it in your XML layout or call setImageResource on it). Then set isFilterBitmap to false on its drawable.
myImageView.setImageResource(R.drawable.mySprite) // if not already set in XML
myImageView.drawable?.isFilterBitmap = false
When a user clicks a button, i keep switching the background of a layout like this in Activity code:
...
mylayout.setBackgroundDrawable(getResources().getDrawable(R.drawable.img1));//On First click
mylayout.setBackgroundDrawable(getResources().getDrawable(R.drawable.img2));//On Second Click
mylayout.setBackgroundDrawable(getResources().getDrawable(R.drawable.img10));//On 10th Click
...
mylayout.setBackgroundDrawable(getResources().getDrawable(R.drawable.img1));//On 11th Click 1st image again and so on.
I have 10 images which i keep rotating.
Soon, it causes OutOfMemory exception. What am i doing wrong?
If it matters in my manifest file i have:
android:minSdkVersion="11"
android:targetSdkVersion="17" />
EDIT 1
Average size of the image is: 50K
Average dimension of the image is: 600x450
All images img1, img2 etc.. are jpeg images
Solution Update
Reducing image dimensions to 300x200 resolved the issue. The memory requirements went down significantly by this single change.
It might be happening because your image resources are in drawable folder; which is equivalent to drawable-mdpi. And your device might be something other than mdpi.
So, either provide images for all the screed densities you are gonna support. Or, put images in drawable-nodpi, so your images will not be resized. Hence no OutOfMemoryException.
Referred from here
Use Bitmap.recycle() if you can change your Drawable with Bitmap.
Hope This will help
Each bitmap with dimension 600x450 has size of 600*450*4 = 1 080 000 bytes (1 MB) in RAM.
You should load so large bitmaps in another way:
Bitmap bitmap = BitmapFactory.decodeResource(resources, R.drawable.img1);
myLayout.setBackgroundDrawable(new BitmapDrawable(resources, bitmap));
And before changing background of the view you have to do
Drawable background = myLayout.getBackground();
if (background != null && background instanceof BitmapDrawable) {
myLayout.setBackgroundDrawable(null);
BitmapDrawable bd = (BitmapDrawable) background;
bd.getBitmap().recycle();
}
I dont think changing background layout so frequently is a good idead. I suggest that you could use RelativeLayout with an ImageView as first item. Then everytime you need to change your background, you can change your ImageView with some cached library such as: Universal Image Loader
The question is this: I have a picture I want to use it in a costum view, so I have to use the Preparebitmap methode where I have to specify the picutres which I want to draw and the Width/Height that the picture will take.
I created the image for all the sizes, I mean there's the same picture with different resulotion (I placed them in the drawable folders (ldpi, mdpi...)); so the main question is how to draw the bitmap to be shown perfectly with all the screen, maybe the following example will clear my problem:
appLogo = prepareBitmap(getResources().getDrawable(R.drawable.applogo), 100, 100);
the bitmap will be drawn in 100X100 space, so in bigger screens, the image will be small, even if it exist in the xx-hdpi folder. Is there any way how to get the real size of the image whatever the screen was ? I want something like:
appLogo = prepareBitmap(getResources().getDrawable(R.drawable.applogo), Height, Width);
with Height/Width are the real Height/Width of the image.
Thank you
I am trying to draw multiple ImageViews inside a single LinearLayout.
All the ImageViews need to have a single bitmap.
The ImageViews will only vary in size.
The single bitmap will not be resized.
The simple way is to create one Bitmap per ImageView. But, this runs out of memory quickly.
final Bitmap placeholderBitmap = Bitmap.createBitmap(width, height, Config.ARGB_8888);
final Canvas canvas = new Canvas(placeholderBitmap);
canvas.drawBitmap(BitmapFactory.decodeResource(getResources(), R.drawable.placeholder_image), 0, 0, null);
imageView.setImageBitmap(placeholderBitmap);
linearLayout.addView(imageView);
I also tried setting the max and min height and width, no effect. The images remain the same size.
imageView.setImageResource(R.drawable.ic_no_image);
imageView.setMaxHeight(imageViewInfo.height);
imageView.setMaxWidth(imageViewInfo.width);
I believe working with Drawables is the right "Android" way to do it, but I can't find a way to dynamically create a Drawable with the right side and layering the shared bitmap into it.
Just use one Bitmap -- as you say they will all use the same Bitmap, so no duplication is necessary.
If you want the ImageViews to have different sizes and have the Bitmap scale itself to the size of the ImageView then use the setScaleType or android:scaleType attribute to set the scaling of the ImageView. For instance FIT_START maintains the aspect ratio of your image and tries to fill the ImageView starting from the top-left corner.
I don't see any need to create a Drawable, though if you need to you can just create one from a Bitmap using:
Drawable d = new BitmapDrawable(bitmap);
ImageView actually does this automatically when you call setImageBitmap(...).
ImageView will always resize the bitmap to it need proportions.
If you want to save memory, resize the bitmaps manually and set them into the ImageViews this should stop the ImageView from resizing it internally - to make sure, you can set the layout_width and layout_hieght of the image view to 'wrap_content'.
I think may be looking for a ClipDrawable.
You would set the android:drawable property of the clip XML to your bitmap
That or you can do it with the Java code also given in the example
I updated my build to build against Android 1.6, and now my bitmaps are scaled down on high density screens. I do NOT want this behavior. I gave this a shot:
http://blog.tomgibara.com/post/190539066/android-unscaled-bitmaps
but the images are STILL scaling, that is UNLESS I set them to a specific height & width. If I use wrap_content they are scaled down.
I have an image loader using the unscaled bitmap loader to create a drawable like so:
Bitmap bm = UnscaledBitmapLoader.loadFromResource(imageBufferInputStream);
drawable = new BitmapDrawable(bm);
which I later assign to an ImageView like so:
imageView.setImageDrawable( copyBitmapDrawable( (BitmapDrawable) drawable) );
In order to have an image not scaled when loading it from a resource (e.g. with BitmapFactory.decodeResource) you have to locate it in res/drawable-nodpi instead of the usual drawable, drawable-ldpi and so on.
Using
new BitmapDrawable(this.getResources(), bmp);
instead of
new BitmapDrawable(bmp);
should solve the issue.
Wrapping the bitmap with a Drawable is the problem. The Drawable scales the Bitmap. Instead of using a Drawable, assign the Bitmap to the ImageView directly using imageView.setImageBitmap(Bitmap).
Use ImageView.ScaleType. The CENTER constant preforms no scaling, so I guess that's what you are looking for.
By the way, do you use pixels or dips as size units? Using dips (density-independent-pixels) is a means of standardizing display on multiple resolutions. You'll find a couple of tips here.