Android image from asset pixelated - android

While developping an Android App, I saw that all my images displayed from the assets are pixelated.
I'm using this 2 lines to display them:
Drawable imageDrawable = Drawable.createFromStream("my_logo.png", null);
imageView.setBackground(imageDrawable);
The images have as dimension: 128/128 or 256/256 and are displayed in a square ImageView.
Do anyone have an idea to keep the quality of my images ?

Changing the dimensions of your image can and will decrease the quality. There are a couple of things you can do
Use vectors instead. Vectors can be scaled up and down infinitely without loss of quality.
Use an ImageView height and width that is the same size as your image or smaller and maintains the aspect ratio.

void setImageDrawable (Drawable drawable)
Sets a drawable as the content of ImageView.
To set drawable to ImageView from java, you need to use setImageDrawable (Drawable drawable) method.
You are setting the drawable as imageView's background, your code should be,
Drawable imageDrawable = Drawable.createFromStream("my_logo.png", null);
imageView.setImageDrawable(imageDrawable);

Related

Android Picasso load image to Bitmap variable cropping it to square

I need to load some images from URI to Bitmap variables and perform some operation with them togheter. I need the bitmaps to be squared images with fixes size, scaled down and cropped. By now I use this code:
return Picasso.with(c).load(imageUri).resize(size, size).get();
but, obviously, the image will be resized without keep its aspect ratio.
I want to resize the image with these requirements:
the smaller dimension (width or height) should be equals to size
the greater dimension should be cropped to size, keep image centered
The key is using centerInside after resize. See link
Picasso.with(c).load(imageUri).resize(size, size).centerInside().get()
set your imageview height and width fix inside xml and then set image to imageview like
Picasso.with(YourActivityName.this)
.load(imageUri)
.into(imageview_id);

Image in ImageView auto scale when display the same BitmapDrawable with another ImageView?

This situation I have met in Android and still can't find any solution.
I have an ImageView display by these code:
BitmapDrawable value = ...;
imageView1.setImageDrawable(value);
Then I use imageView2 to display the same image in Drawable:
imageView2.setImageDrawable(value);
And ops,... the image in imageView1 auto scale and become bigger than the older. (imageView2 is bigger than imageView1).
Is there anyone saw this situation before?
Drawables are immutable, so the one bitmap is getting scaled and then shown by both ImageViews.
To get a different (unshared) version for the second one, try:
imageView2.setImageDrawable(value.mutate());

Android avoid image scalling in Imageview for Image Mapping like Html

Hi Am trying to implement image mapping as like html in android. For that i referred this project. Its work good when i access the image from drawable-nodpi folder. But when i access from other drawable folder the image get scaled as per the android concepts. Here i used drawable folder for checking purpose only. Actually i get image from back end service.
I also tried with bitmap by setting the no density.
Bitmap bm;
bm=BitmapFactory.decodeResource(getResources(), R.drawable.blueprint);
bm.setDensity(Bitmap.DENSITY_NONE);
mImageMap.setImageBitmap(bm); //mImageMap is customized view which extends Imageview
But it's not working. Am also tried as per this post. Its not working.Is there any way to load image to image view without scaling?
you can use Bitmap.createScaledBitmap with the orignal mesaures of the picture..
int width = orignal bitmap width
int height = orignal bitmap height
Bitmap bm;
bm = getBitmap... from network
bm = Bitmap.createScaledBitmap(bm,width,height,true);
this will create a image scaled properly and just place it in the ImageView.

Drawing a large number of ImageViews with the same Bitmap but different size

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

Android: How to stop Android 1.6+ from scaling images

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.

Categories

Resources