Downsampling images using LayoutParams causes unsmoothness

Asked May 18 '15 at 04:55

Active May 18 '15 at 05:46

Viewed 41 times

I am trying to make an ImageView smaller as the user scrolls, using LayoutParams. The problem is, when the imageview size is decreased, it looks awful due to the default downsampling which occurs -

Original

Resized and jaggy image

Resized

Original Layout

Code

Downsampling

@Override
public void onScrollChanged(int scrollY, boolean firstScroll, boolean b1) {

    int newCoverWidth = (int) (initialCoverWidth - (float) scrollY / 1.8);
    //ImageView which is resized
    ivBookCover.getLayoutParams().width = Math.max(newCoverWidth, initialCoverWidth / 2);
    rvBookPanel.setTranslationY(Math.max(-scrollY / 4, -initialToolBarHeight / 4));

    ivBookCover.requestLayout();
}

Setting of Bitmap

    Bitmap bmp = BitmapFactory.decodeByteArray(byteArray, 0, byteArray.length);
    ivBookCover.setImageBitmap(bmp);

What should i do to improve downscaling and get a smooth image

edited May 18 '15 at 05:46

asked May 18 '15 at 04:55

Shubham Kanodia

6,036
3
32
46

BitmapDrawable#setFilterBitmap(boolean filter) / BitmapDrawable#setDither(boolean dither) ? – pskink May 18 '15 at 05:31
@pskink Tried setting both to true.. no difference at all. – Shubham Kanodia May 18 '15 at 05:47
tried only setFilterBitmap? – pskink May 18 '15 at 05:51
@pskink I did.. Bitmap bmp = BitmapFactory.decodeByteArray(byteArray, 0, byteArray.length); Drawable d = new BitmapDrawable(getResources(), bmp); d.setFilterBitmap(true); ivBookCover.setImageDrawable(d); – Shubham Kanodia May 18 '15 at 05:54
so the only way is to create a custom BitmapDrawable, override `draw()` and draw the stuff as you like – pskink May 18 '15 at 05:55