Develop Reference

Images scales defferently in setImageDrawable() and setImageBitmap()?

I am new in android development. I have an issue regarding the image scaling in my app. When i set images using setImageDrawable() images look proper like in screenshot:
But if i set image using setImageBitmap() method it does not look proper. Some black color occurs around it like in screenshot bellow:
I have tried it in multiple applications and i observed that in some applications the image size is becoming smaller than the size ofter setting image through setImageDrawable() or setImageResource().
the reason for setting images through setImageBitmap() is that i want to set images to the imageviews which are kept in assets folder and not in drawable.
Following is the code i used to create a bitmap and set it to imageview:
BitmapFactory.Options opts = new Options();
opts.inPurgeable = true;
try
{
Bitmap preview_bitmap = BitmapFactory.decodeStream(assetManager.open(drawableFolder+"/"+tmpArr[0]),null,opts);
view.setImageBitmap(preview_bitmap);
}
catch (Exception e)
{
LNLog.writeTOErrorToLog(e.getMessage());
}
So, please can anyone tell me where i'm i going wrong or missing something to set.
I tried to set Options but did not worked. I want to set images as in first screenshot that is how they looks by using setImageDrawable().
Thanx in advance.
Note: in screenshots images are referent in text on it only.IF i set hindi images i.e. the images on which text is in hindi language using setImageDrawable() then they looks proper as in like in screen shot one.So , no issue of image files.

You can get rid of the black borders by using
android:adjustViewBounds="true" in xml
or
imageView.setAdjustViewBounds(true) in Java.
EDIT:
Then try using drawable only
Drawable d = Drawable.createFromStream(assetManager.open(filePath), null);
view.setImageDrawable(d)

This worked for me :
try
{
view.setAdjustViewBounds(true);
int height = view.getDrawable().getIntrinsicHeight();
int width = view.getDrawable().getIntrinsicWidth();
BitmapFactory.Options opts = new BitmapFactory.Options();
opts.inPurgeable = true;
opts.inScaled = true;
Bitmap preview_bitmap = BitmapFactory.decodeStream(assetManager.open("drawable-mdpi/FAQ_hi_in.png",null,opts);
Bitmap bmp = Bitmap.createScaledBitmap(preview_bitmap, width, height, true);
view.setImageBitmap(bmp);
}
In this code I have taken the height and width of actual image and then scaled my bitmap to that height and width. Then I converted this scaled bitmap to drawable and set it into my ImageView, thats it. It resolved my problem of black border around image.

How to get the original dimensions of a image passed to ImageView?

I am trying to subclass ImageView to create a custom view.
public class MyImageView extends ImageView
Now I pass to MyImageView an image via setImageResource(int resId)
Now, I need to get the original dimensions of the image passed,
I need to do that from inside MyImageView so that I can use the dimension for my implementation of onDraw().
How do I do that?

Android's Drawable provides getIntrinsicHeight and getIntrinsicWidth methods which are supposed to return a preferred ("real" in some sense) size of an underlying drawable object, if it supports size attribute at all. I assume they should work in your case as far as you read real images, but if, for some reason, they don't (i.e. return -1), possible workarounds could be to parse image header (for example, bitmap header or SVG document, manually or using existing image libraries), or store a map with dimensions of your graphic resources along with the resources themselves.

Bitmap image = BitmapFactory.decodeResource(getResources(), R.drawable.yourBitmap);
Then try image.getWidth and image.getHeight()
UPDATE
you can set decodebounds true and pass that bounds to get dimensions without decoding whole bitmap

Bitmap bitmap = ((BitmapDrawable)imageView.getDrawable()).getBitmap();
int height = bitmap.getHeight();
int width = bitmap.getWidth();

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

How to prevent an image from being resized in Android

I am writing an application on android. I am downloading an image from the server and trying to set it as an ImageView background using setBackgroundDrawable.
Drawable drawable = Drawable.createFromPath(path)
imageView.setBackgroundDrawable(drawable);
It works but the image is resized (it is getting smaller). Does anyone have an idea about how to set an image view background without changing its size?
Edit:
I solved the problem by using:
File imgFile = new File(path);
Bitmap myBitmap = BitmapFactory.decodeFile(imgFile.getAbsolutePath());
imageView.setImageBitmap(myBitmap);

imageView.setScaleType (ImageView.ScaleType.MATRIX)
Set image scale type to Matrix it will scale using the image matrix when drawing.

Use these two properties:
android:scaleType
android:adjustViewBounds
Study about them in : ImageView

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.