Bitmap的图片压缩汇总 - Android成长之路

    public enum CompressFormat {
        JPEG    (0),
        PNG     (1),
        WEBP    (2);

        CompressFormat(int nativeInt) {
            this.nativeInt = nativeInt;
        }
        final int nativeInt;
    }

val fs = FileOutputStream(path)
val out = ByteArrayOutputStream()
scaleBitmap.compress(Bitmap.CompressFormat.JPEG, 30, out)
LogUtils.d("compressBitmap jpeg of byteCount %d.", out.toByteArray().size)
fs.write(out.toByteArray())
fs.close()

val colors = intArrayOf(Color.RED, Color.GREEN, Color.BLUE,
                        Color.GREEN, Color.BLUE, Color.RED,
                        Color.BLUE, Color.RED, Color.GREEN)
val displayMetricsBitmap = Bitmap.createBitmap(DisplayMetrics(),colors,3, 3,Bitmap.Config.ARGB_8888)
LogUtils.d("displayMetricsBitmap of byteCount %d and rowBytes %d", displayMetricsBitmap.byteCount, displayMetricsBitmap.rowBytes)

//bitmap
val bitmapBitmap = Bitmap.createBitmap(scaleBitmap, 150, 0, 100, 100)
image_view?.setImageBitmap(scaleBitmap)
image_view_text.text = "width: " + scaleBitmap.width + " height: " + scaleBitmap.height
sub_image_view.setImageBitmap(bitmapBitmap)
sub_image_view_text.text = "startX: 150 startY: 0\n" + "width: " + bitmapBitmap.width + " height: " + bitmapBitmap.height

if (!source.isMutable() && x == 0 && y == 0 && width == source.getWidth() &&
        height == source.getHeight() && (m == null || m.isIdentity())) {
    return source;
 }

//createScaledBitmap
val createScaledBitmap = Bitmap.createScaledBitmap(scaleBitmap, 500, 300, false)
image_view?.setImageBitmap(scaleBitmap)
image_view_text.text = "width: " + scaleBitmap.width + " height: " + scaleBitmap.height
sub_image_view.setImageBitmap(createScaledBitmap)
sub_image_view_text.text = "width: " + createScaledBitmap.width + " height: " + createScaledBitmap.height

    public static Bitmap createScaledBitmap(@NonNull Bitmap src, int dstWidth, int dstHeight,
            boolean filter) {
        Matrix m = new Matrix();
 
        final int width = src.getWidth();
        final int height = src.getHeight();
        if (width != dstWidth || height != dstHeight) {
            final float sx = dstWidth / (float) width;
            final float sy = dstHeight / (float) height;
            m.setScale(sx, sy);
        }
        return Bitmap.createBitmap(src, 0, 0, width, height, m, filter);
    }

//decodeFile
val decodeFileOptions = BitmapFactory.Options()
val decodeFileBitmap = BitmapFactory.decodeFile(mRootPath +"bitmap", decodeFileOptions)
decodeFileOptions.inSampleSize = 2
val decodeFileScaleBitmap = BitmapFactory.decodeFile(mRootPath + "bitmap", decodeFileOptions)
image_view?.setImageBitmap(decodeFileBitmap)
image_view_text.text = "width: " + decodeFileBitmap.width + " height: " + decodeFileBitmap.height
sub_image_view.setImageBitmap(decodeFileScaleBitmap)
sub_image_view_text.text = "width: " + decodeFileScaleBitmap.width + " height: " + decodeFileScaleBitmap.height

decodeFileOptions.inSampleSize = 2

    public static Bitmap decodeFile(String pathName, Options opts) {
        validate(opts);
        Bitmap bm = null;
        InputStream stream = null;
        try {
            stream = new FileInputStream(pathName);
            bm = decodeStream(stream, null, opts);
        } catch (Exception e) {
            /*  do nothing.
                If the exception happened on open, bm will be null.
            */
            Log.e("BitmapFactory", "Unable to decode stream: " + e);
        } finally {
            if (stream != null) {
                try {
                    stream.close();
                } catch (IOException e) {
                    // do nothing here
                }
            }
        }
        return bm;
    }

nativeDecodeAsset(asset, outPadding, opts);

nativeDecodeStream(is, tempStorage, outPadding, opts);

    public static Bitmap decodeResourceStream(Resources res, TypedValue value,
            InputStream is, Rect pad, Options opts) {
        validate(opts);
        if (opts == null) {
            opts = new Options();
        }
 
        if (opts.inDensity == 0 && value != null) {
            final int density = value.density;
            if (density == TypedValue.DENSITY_DEFAULT) {
                opts.inDensity = DisplayMetrics.DENSITY_DEFAULT;
            } else if (density != TypedValue.DENSITY_NONE) {
                opts.inDensity = density;
            }
        }
         
        if (opts.inTargetDensity == 0 && res != null) {
            opts.inTargetDensity = res.getDisplayMetrics().densityDpi;
        }
         
        return decodeStream(is, pad, opts);
    }

val options = BitmapFactory.Options()
val bitmap = BitmapFactory.decodeResource(resources, R.drawable.yaodaoji, options)

    public static Bitmap decodeResource(Resources res, int id, Options opts) {
        validate(opts);
        Bitmap bm = null;
        InputStream is = null; 
         
        try {
            final TypedValue value = new TypedValue();
            is = res.openRawResource(id, value);

            bm = decodeResourceStream(res, value, is, null, opts);
        } catch (Exception e) {
            /*  do nothing.
                If the exception happened on open, bm will be null.
                If it happened on close, bm is still valid.
            */
        } finally {
            try {
                if (is != null) is.close();
            } catch (IOException e) {
                // Ignore
            }
        }
 
        if (bm == null && opts != null && opts.inBitmap != null) {
            throw new IllegalArgumentException("Problem decoding into existing bitmap");
        }
 
        return bm;
    }