Tuesday, April 10, 2012

How to make glow effect around a bitmap?


The following code is what I got so far. However, there are 2 issues:





  1. I want both inner and outer glow effects, which looking similar to the Photoshop's blending options. But I only managed to make the outer glow, if I set BlurMaskFilter.Blur.INNER or other value, the whole image is blocked, instead of just edges.





  2. Despite I set "FF" as alpha value, the glow color is still very dark.




    Bitmap alpha = origin.extractAlpha();
    BlurMaskFilter blurMaskFilter = new BlurMaskFilter(5, BlurMaskFilter.Blur.OUTER);


    Paint paint = new Paint();
    paint.setMaskFilter(blurMaskFilter);
    paint.setColor(0xffffffff);


    Canvas canvas = new Canvas(origin);
    canvas.drawBitmap(alpha, 0, 0, paint);


    return origin;





alt text


Source: Tips4all

2 comments:

  1. I think there is no method in android to create glow effects. you have to make them yourself from scratch or find some java library that supports this.

    the simplest thing that i prefer to use is making layers of images. basically you define a relative layout and put 2 imageViews one on top of another. just create the photoshop effect in its own layer and rasterize that layer, save it to png place it on top of your image. But careful if you are using this method with large images you can easily get that VM exceeded exception. Resampling the bitmaps according to the view size is a pretty good solution for this issue.

    the other method that comes to my mind is drawing gradients over your image (ex: radial gradient that is transparent in the middle and white among the edges- to get a white glow) but this way takes a lot of time to tune up to exactly what you need so in my opinion isn't worth the effort).

    Also here is a link for a site that makes java image filters. maybe you can find something that does the job for you.

    http://www.jhlabs.com/ip/filters/index.html

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  2. How about this:

    <LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:background="@color/Black"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <TextView android:textColor="@color/White"
    android:layout_width="wrap_content"
    android:text="Glowing Text"
    android:layout_height="wrap_content"
    android:padding="2dp"
    android:shadowColor="@color/White"
    android:shadowDx="0"
    android:shadowDy="0"
    android:shadowRadius="3" />
    </LinearLayout>


    found here: http://blog.stylingandroid.com/archives/378:

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