Android的Bitmap类中常用方法

boolean	compress(Bitmap.CompressFormat format, int quality, OutputStream stream) Write a compressed version of the bitmap to the specified outputstream.（压缩图片以特定格式输出到输出流）
Bitmap	copy(Bitmap.Config config, boolean isMutable) Tries to make a new bitmap based on the dimensions of this bitmap, setting the new bitmap's config to the one specified, and then copying this bitmap's pixels into the new bitmap.（复制bitmap，可以指定所需复制的配置信息以及是否允许被修改）
void	copyPixelsFromBuffer(Buffer src) Copy the pixels from the buffer, beginning at the current position, overwriting the bitmap's pixels.
void	copyPixelsToBuffer(Buffer dst) Copy the bitmap's pixels into the specified buffer (allocated by the caller).
static Bitmap	createBitmap(DisplayMetrics display, int[] colors, int width, int height, Bitmap.Config config) Returns a immutable可变的 bitmap with the specified width and height, with each pixel value set to the corresponding value in the colors array.
static Bitmap	createBitmap(DisplayMetrics display, int[] colors, int offset, int stride, int width, int height, Bitmap.Config config) Returns a immutable bitmap with the specified width and height, with each pixel value set to the corresponding value in the colors array.
static Bitmap	createBitmap(Bitmap source, int x, int y, int width, int height) Returns an immutable bitmap from the specified subset of the source bitmap.
static Bitmap	createBitmap(Bitmap src) Returns an immutable bitmap from the source bitmap.（对原图的复制）
static Bitmap	createBitmap(DisplayMetrics display, int width, int height, Bitmap.Config config) Returns a mutable bitmap with the specified width and height.
static Bitmap	createBitmap(Bitmap source, int x, int y, int width, int height, Matrix m, boolean filter) Returns an immutable bitmap from subset of the source bitmap, transformed by the optional matrix.
static Bitmap	createBitmap(int width, int height, Bitmap.Config config) Returns a mutable bitmap with the specified width and height.
static Bitmap	createBitmap(int[] colors, int offset, int stride, int width, int height, Bitmap.Config config) Returns a immutable bitmap with the specified width and height, with each pixel value set to the corresponding value in the colors array.
static Bitmap	createBitmap(int[] colors, int width, int height, Bitmap.Config config) Returns a immutable bitmap with the specified width and height, with each pixel value set to the corresponding value in the colors array.
static Bitmap	createScaledBitmap(Bitmap src, int dstWidth, int dstHeight, boolean filter) Creates a new bitmap, scaled from an existing bitmap, when possible.（将原有的图按比例缩放保存）
int	describeContents() No special parcel contents.
void	eraseColor(int c) Fills the bitmap's pixels with the specified  Color.
Bitmap	extractAlpha() Returns a new bitmap that captures the alpha values of the original.
Bitmap	extractAlpha(Paint paint, int[] offsetXY) Returns a new bitmap that captures the alpha values of the original.
final int	getAllocationByteCount() Returns the size of the allocated memory used to store this bitmap's pixels.
final int	getByteCount() Returns the minimum number of bytes that can be used to store this bitmap's pixels.
final Bitmap.Config	getConfig() If the bitmap's internal config is in one of the public formats, return that config, otherwise return null.（返回图片配置信息）
int	getDensity() Returns the density for this bitmap.
int	getGenerationId() Returns the generation ID of this bitmap.
final int	getHeight() Returns the bitmap's height
byte[]	getNinePatchChunk() Returns an optional array of private data, used by the UI system for some bitmaps.
int	getPixel(int x, int y) Returns the Color at the specified location.
void	getPixels(int[] pixels, int offset, int stride, int x, int y, int width, int height) Returns in pixels[] a copy of the data in the bitmap.
final int	getRowBytes() Return the number of bytes between rows in the bitmap's pixels.
int	getScaledHeight(DisplayMetrics metrics) Convenience for calling  getScaledHeight(int) with the target density of the given  DisplayMetrics.
int	getScaledHeight(int targetDensity) Convenience method that returns the height of this bitmap divided by the density scale factor.
int	getScaledHeight(Canvas canvas) Convenience for calling  getScaledHeight(int) with the target density of the given  Canvas.
int	getScaledWidth(int targetDensity) Convenience method that returns the width of this bitmap divided by the density scale factor.
int	getScaledWidth(DisplayMetrics metrics) Convenience for calling  getScaledWidth(int) with the target density of the given  DisplayMetrics.
int	getScaledWidth(Canvas canvas) Convenience for calling  getScaledWidth(int) with the target density of the given  Canvas.
final int	getWidth() Returns the bitmap's width
final boolean	hasAlpha() Returns true if the bitmap's config supports per-pixel alpha, and if the pixels may contain non-opaque alpha values.
final boolean	hasMipMap() Indicates whether the renderer responsible for drawing this bitmap should attempt to use mipmaps when this bitmap is drawn scaled down.
final boolean	isMutable() Returns true if the bitmap is marked as mutable可变的 (i.e. can be drawn into)
final boolean	isPremultiplied() Indicates whether pixels stored in this bitmaps are stored pre-multiplied.
final boolean	isRecycled() Returns true if this bitmap has been recycled.
void	prepareToDraw() Rebuilds any caches associated with the bitmap that are used for drawing it.
void	reconfigure(int width, int height, Bitmap.Config config) Modifies the bitmap to have a specified width, height, and Bitmap.Config, without affecting the underlying allocation backing the bitmap.
void	recycle() Free the native object associated with this bitmap, and clear the reference to the pixel data.
boolean	sameAs(Bitmap other) Given another bitmap, return true if it has the same dimensions, config, and pixel data as this bitmap.
void	setConfig(Bitmap.Config config) Convenience method for calling reconfigure(int, int, Config) with the current height and width.
void	setDensity(int density) Specifies the density for this bitmap.
void	setHasAlpha(boolean hasAlpha) Tell the bitmap if all of the pixels are known to be opaque (false) or if some of the pixels may contain non-opaque alpha values (true).
final void	setHasMipMap(boolean hasMipMap) Set a hint for the renderer responsible for drawing this bitmap indicating that it should attempt to use mipmaps when this bitmap is drawn scaled down.
void	setHeight(int height) Convenience method for calling reconfigure(int, int, Config) with the current width and config.
void	setPixel(int x, int y, int color) Write the specified Color into the bitmap (assuming it is mutable) at the x,y coordinate.
void	setPixels(int[] pixels, int offset, int stride, int x, int y, int width, int height) Replace pixels in the bitmap with the colors in the array.
final void	setPremultiplied(boolean premultiplied) Sets whether the bitmap should treat its data as pre-multiplied.
void	setWidth(int width) Convenience method for calling reconfigure(int, int, Config) with the current height and config.
void	writeToParcel(Parcel p, int flags) Write the bitmap and its pixels to the parcel.