学步园

options.inSampleSize = 4;<br /> options.inDither = false;<br /> options.inPreferredConfig = Bitmap.Config.ARGB_8888;<br /> options.inJustDecodeBounds = false;<br /> Bitmap b = BitmapFactory.decodeResource(getResources(), R.drawable.sam,<br /> options);<br /> Bitmap b2 = extractMiniThumb(b, 90, 130, true);<br /> File f = new File("/sdcard/s.jpg");<br /> try {<br /> BufferedOutputStream w = new BufferedOutputStream(<br /> new FileOutputStream(f));<br /> b2.compress(Bitmap.CompressFormat.JPEG, 85, w);<br /> } catch (FileNotFoundException e) {<br /> // TODO Auto-generated catch block<br /> e.printStackTrace();<br /> }</p> <p>public static Bitmap extractMiniThumb(Bitmap source, int width, int height,<br /> boolean recycle) {<br /> if (source == null) {<br /> return null;<br /> }<br /> float scale;<br /> if (source.getWidth() < source.getHeight()) {<br /> scale = width / (float) source.getWidth();<br /> } else {<br /> scale = height / (float) source.getHeight();<br /> }<br /> Matrix matrix = new Matrix();<br /> matrix.setScale(scale, scale);<br /> Bitmap miniThumbnail = transform(matrix, source, width, height, true,<br /> recycle);<br /> return miniThumbnail;<br /> }</p> <p>public static Bitmap transform(Matrix scaler, Bitmap source,<br /> int targetWidth, int targetHeight, boolean scaleUp, boolean recycle) {<br /> int deltaX = source.getWidth() - targetWidth;<br /> int deltaY = source.getHeight() - targetHeight;<br /> if (!scaleUp && (deltaX < 0 || deltaY < 0)) {<br /> /*<br /> * In this case the bitmap is smaller, at least in one dimension,<br /> * than the target. Transform it by placing as much of the image as<br /> * possible into the target and leaving the top/bottom or left/right<br /> * (or both) black.<br /> */<br /> Bitmap b2 = Bitmap.createBitmap(targetWidth, targetHeight,<br /> Bitmap.Config.ARGB_8888);<br /> Canvas c = new Canvas(b2);<br /> int deltaXHalf = Math.max(0, deltaX / 2);<br /> int deltaYHalf = Math.max(0, deltaY / 2);<br /> Rect src = new Rect(deltaXHalf, deltaYHalf, deltaXHalf<br /> + Math.min(targetWidth, source.getWidth()), deltaYHalf<br /> + Math.min(targetHeight, source.getHeight()));<br /> int dstX = (targetWidth - src.width()) / 2;<br /> int dstY = (targetHeight - src.height()) / 2;<br /> Rect dst = new Rect(dstX, dstY, targetWidth - dstX, targetHeight<br /> - dstY);<br /> c.drawBitmap(source, src, dst, null);<br /> if (recycle) {<br /> source.recycle();<br /> }<br /> return b2;<br /> }<br /> float bitmapWidthF = source.getWidth();<br /> float bitmapHeightF = source.getHeight();<br /> float bitmapAspect = bitmapWidthF / bitmapHeightF;<br /> float viewAspect = (float) targetWidth / targetHeight;<br /> if (bitmapAspect > viewAspect) {<br /> float scale = targetHeight / bitmapHeightF;<br /> if (scale < .9F || scale > 1F) {<br /> scaler.setScale(scale, scale);<br /> } else {<br /> scaler = null;<br /> }<br /> } else {<br /> float scale = targetWidth / bitmapWidthF;<br /> if (scale < .9F || scale > 1F) {<br /> scaler.setScale(scale, scale);<br /> } else {<br /> scaler = null;<br /> }<br /> }<br /> Bitmap b1;<br /> if (scaler != null) {<br /> // this is used for minithumb and crop, so we want to filter here.<br /> b1 = Bitmap.createBitmap(source, 0, 0, source.getWidth(), source<br /> .getHeight(), scaler, true);<br /> } else {<br /> b1 = source;<br /> }<br /> if (recycle && b1 != source) {<br /> source.recycle();<br /> }<br /> int dx1 = Math.max(0, b1.getWidth() - targetWidth);<br /> int dy1 = Math.max(0, b1.getHeight() - targetHeight);<br /> Bitmap b2 = Bitmap.createBitmap(b1, dx1 / 2, dy1 / 2, targetWidth,<br /> targetHeight);<br /> if (b2 != b1) {<br /> if (recycle || b1 != source) {<br /> b1.recycle();<br /> }<br /> }<br /> return b2;<br /> }<br /> }