theo dõi

Gần nhất :

Tags

Thống kê câu hỏi

Chuyên mục : Lập trình
Topic : Android
Hỏi lúc:
Lượt xem: 1,883

Hướng dẫn blur một ảnh bitmap

Thanh  Thinh Thanh Thinh
 57  26  62
01 bình chọn hữu ích bởi Nguyễn Hải Lý

Hi cả nhà . Các ứng dụng  bây giờ có phần avatar ảnh . Nếu bạn muốn thêm hiệu ứng blur ảnh ( mờ ảnh ).

Khái niệm về blur ảnh mọi người tham khảo ở đây nhé.

http://www.tutorialspoint.com/dip/concept_of_blurring.htm

@SuppressLint("NewApi")
    public static Bitmap blurRenderScript(Context context, Bitmap smallBitmap, int radius) {
        //http://stackoverflow.com/questions/32786838/android-renderscript-support-library-error-loading-rs-jni-library?rq=1
        //https://code.google.com/p/android/issues/detail?id=68520
        final String architecture = System.getProperty("os.arch");
        Log.d("architecture", architecture);
        if ("armeabi-v7a".equalsIgnoreCase(architecture)) {
            try {
                RenderScript renderScript = RenderScript.create(context);

                smallBitmap = RGB565toARGB888(smallBitmap);

                Bitmap bitmap = Bitmap.createBitmap(
                        smallBitmap.getWidth(), smallBitmap.getHeight(),
                        Bitmap.Config.ARGB_8888);

                Allocation blurInput = Allocation.createFromBitmap(renderScript, smallBitmap);
                Allocation blurOutput = Allocation.createFromBitmap(renderScript, bitmap);

                ScriptIntrinsicBlur blur = ScriptIntrinsicBlur.create(renderScript,
                        Element.U8_4(renderScript));
                blur.setInput(blurInput);
                blur.setRadius(radius); // radius must be 0 < r <= 25
                blur.forEach(blurOutput);

                blurOutput.copyTo(bitmap);
                renderScript.destroy();

                return bitmap;
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        // This devices architecture not supported blur image.
//        // I just used flag filter=true in bitmap = Bitmap.createScaledBitmap(bitmap, width, height, true); for blur.
//        return Bitmap.createScaledBitmap(smallBitmap, smallBitmap.getWidth(), smallBitmap.getHeight(), true);
        //http://stackoverflow.com/questions/2067955/fast-bitmap-blur-for-android-sdk
        return fastblur(smallBitmap, 1, radius);
    }

    /**
     * Stack Blur v1.0 from
     * http://www.quasimondo.com/StackBlurForCanvas/StackBlurDemo.html
     * Java Author: Mario Klingemann <mario at quasimondo.com>
     * http://incubator.quasimondo.com
     * <p/>
     * created Feburary 29, 2004
     * Android port : Yahel Bouaziz <yahel at kayenko.com>
     * http://www.kayenko.com
     * ported april 5th, 2012
     * <p/>
     * This is a compromise between Gaussian Blur and Box blur
     * It creates much better looking blurs than Box Blur, but is
     * 7x faster than my Gaussian Blur implementation.
     * <p/>
     * I called it Stack Blur because this describes best how this
     * filter works internally: it creates a kind of moving stack
     * of colors whilst scanning through the image. Thereby it
     * just has to add one new block of color to the right side
     * of the stack and remove the leftmost color. The remaining
     * colors on the topmost layer of the stack are either added on
     * or reduced by one, depending on if they are on the right or
     * on the left side of the stack.
     * <p/>
     * If you are using this algorithm in your code please add
     * the following line:
     * Stack Blur Algorithm by Mario Klingemann <mario@quasimondo.com>
     */

    public static Bitmap fastblur(Bitmap sentBitmap, float scale, int radius) {

        int width = Math.round(sentBitmap.getWidth() * scale);
        int height = Math.round(sentBitmap.getHeight() * scale);
        sentBitmap = Bitmap.createScaledBitmap(sentBitmap, width, height, false);

        Bitmap bitmap = sentBitmap.copy(sentBitmap.getConfig(), true);

        if (radius < 1) {
            return (null);
        }

        int w = bitmap.getWidth();
        int h = bitmap.getHeight();

        int[] pix = new int[w * h];
        Log.e("pix", w + " " + h + " " + pix.length);
        bitmap.getPixels(pix, 0, w, 0, 0, w, h);

        int wm = w - 1;
        int hm = h - 1;
        int wh = w * h;
        int div = radius + radius + 1;

        int r[] = new int[wh];
        int g[] = new int[wh];
        int b[] = new int[wh];
        int rsum, gsum, bsum, x, y, i, p, yp, yi, yw;
        int vmin[] = new int[Math.max(w, h)];

        int divsum = (div + 1) >> 1;
        divsum *= divsum;
        int dv[] = new int[256 * divsum];
        for (i = 0; i < 256 * divsum; i++) {
            dv[i] = (i / divsum);
        }

        yw = yi = 0;

        int[][] stack = new int[div][3];
        int stackpointer;
        int stackstart;
        int[] sir;
        int rbs;
        int r1 = radius + 1;
        int routsum, goutsum, boutsum;
        int rinsum, ginsum, binsum;

        for (y = 0; y < h; y++) {
            rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0;
            for (i = -radius; i <= radius; i++) {
                p = pix[yi + Math.min(wm, Math.max(i, 0))];
                sir = stack[i + radius];
                sir[0] = (p & 0xff0000) >> 16;
                sir[1] = (p & 0x00ff00) >> 8;
                sir[2] = (p & 0x0000ff);
                rbs = r1 - Math.abs(i);
                rsum += sir[0] * rbs;
                gsum += sir[1] * rbs;
                bsum += sir[2] * rbs;
                if (i > 0) {
                    rinsum += sir[0];
                    ginsum += sir[1];
                    binsum += sir[2];
                } else {
                    routsum += sir[0];
                    goutsum += sir[1];
                    boutsum += sir[2];
                }
            }
            stackpointer = radius;

            for (x = 0; x < w; x++) {

                r[yi] = dv[rsum];
                g[yi] = dv[gsum];
                b[yi] = dv[bsum];

                rsum -= routsum;
                gsum -= goutsum;
                bsum -= boutsum;

                stackstart = stackpointer - radius + div;
                sir = stack[stackstart % div];

                routsum -= sir[0];
                goutsum -= sir[1];
                boutsum -= sir[2];

                if (y == 0) {
                    vmin[x] = Math.min(x + radius + 1, wm);
                }
                p = pix[yw + vmin[x]];

                sir[0] = (p & 0xff0000) >> 16;
                sir[1] = (p & 0x00ff00) >> 8;
                sir[2] = (p & 0x0000ff);

                rinsum += sir[0];
                ginsum += sir[1];
                binsum += sir[2];

                rsum += rinsum;
                gsum += ginsum;
                bsum += binsum;

                stackpointer = (stackpointer + 1) % div;
                sir = stack[(stackpointer) % div];

                routsum += sir[0];
                goutsum += sir[1];
                boutsum += sir[2];

                rinsum -= sir[0];
                ginsum -= sir[1];
                binsum -= sir[2];

                yi++;
            }
            yw += w;
        }
        for (x = 0; x < w; x++) {
            rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0;
            yp = -radius * w;
            for (i = -radius; i <= radius; i++) {
                yi = Math.max(0, yp) + x;

                sir = stack[i + radius];

                sir[0] = r[yi];
                sir[1] = g[yi];
                sir[2] = b[yi];

                rbs = r1 - Math.abs(i);

                rsum += r[yi] * rbs;
                gsum += g[yi] * rbs;
                bsum += b[yi] * rbs;

                if (i > 0) {
                    rinsum += sir[0];
                    ginsum += sir[1];
                    binsum += sir[2];
                } else {
                    routsum += sir[0];
                    goutsum += sir[1];
                    boutsum += sir[2];
                }

                if (i < hm) {
                    yp += w;
                }
            }
            yi = x;
            stackpointer = radius;
            for (y = 0; y < h; y++) {
                // Preserve alpha channel: ( 0xff000000 & pix[yi] )
                pix[yi] = (0xff000000 & pix[yi]) | (dv[rsum] << 16) | (dv[gsum] << 8) | dv[bsum];

                rsum -= routsum;
                gsum -= goutsum;
                bsum -= boutsum;

                stackstart = stackpointer - radius + div;
                sir = stack[stackstart % div];

                routsum -= sir[0];
                goutsum -= sir[1];
                boutsum -= sir[2];

                if (x == 0) {
                    vmin[y] = Math.min(y + r1, hm) * w;
                }
                p = x + vmin[y];

                sir[0] = r[p];
                sir[1] = g[p];
                sir[2] = b[p];

                rinsum += sir[0];
                ginsum += sir[1];
                binsum += sir[2];

                rsum += rinsum;
                gsum += ginsum;
                bsum += binsum;

                stackpointer = (stackpointer + 1) % div;
                sir = stack[stackpointer];

                routsum += sir[0];
                goutsum += sir[1];
                boutsum += sir[2];

                rinsum -= sir[0];
                ginsum -= sir[1];
                binsum -= sir[2];

                yi += w;
            }
        }

        Log.e("pix", w + " " + h + " " + pix.length);
        bitmap.setPixels(pix, 0, w, 0, 0, w, h);

        return (bitmap);
    }

    public static Bitmap RGB565toARGB888(Bitmap img) throws Exception {
        int numPixels = img.getWidth() * img.getHeight();
        int[] pixels = new int[numPixels];

        //Get JPEG pixels.  Each int is the color values for one pixel.
        img.getPixels(pixels, 0, img.getWidth(), 0, 0, img.getWidth(), img.getHeight());

        //Create a Bitmap of the appropriate format.
        Bitmap result = Bitmap.createBitmap(img.getWidth(), img.getHeight(), Bitmap.Config.ARGB_8888);

        //Set RGB pixels.
        result.setPixels(pixels, 0, result.getWidth(), 0, 0, result.getWidth(), result.getHeight());
        return result;
    }

 

1,883 xem 03 theo dõi 01 hữu ích hỏi –

Bạn biết ai đó có thể trả lời câu hỏi này?. Bạn có thể giúp đỡ bằng cách tìm những người giỏi nhất:

user user user user user

Hack  Hai Hack Hai
 00  01  01

Tại sao trước khi blur, phải chuyển từ rgb565 sang argb888, ảnh rgb565 có dung lượng thấp hơn mà

898 xem 00 hữu ích trả lời –