Bitmap

DENSITY_NONE

int DENSITY_NONE

Indicates that the bitmap was created for an unknown pixel density.

Constant Value: 0 (0x00000000)

CREATOR

Creator<Bitmap> CREATOR

compress

boolean compress (Bitmap.CompressFormat format, 
                int quality, 
                OutputStream stream)

Write a compressed version of the bitmap to the specified outputstream. If this returns true, the bitmap can be reconstructed by passing a corresponding inputstream to BitmapFactory.decodeStream(). Note: not all Formats support all bitmap configs directly, so it is possible that the returned bitmap from BitmapFactory could be in a different bitdepth, and/or may have lost per-pixel alpha (e.g. JPEG only supports opaque pixels).

copy

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. If the conversion is not supported, or the allocator fails, then this returns NULL. The returned bitmap initially has the same density as the original.

copyPixelsFromBuffer

void copyPixelsFromBuffer (Buffer src)

Copy the pixels from the buffer, beginning at the current position, overwriting the bitmap's pixels. The data in the buffer is not changed in any way (unlike setPixels(), which converts from unpremultipled 32bit to whatever the bitmap's native format is.

After this method returns, the current position of the buffer is updated: the position is incremented by the number of elements read from the buffer. If you need to read the bitmap from the buffer again you must first rewind the buffer.

copyPixelsToBuffer

void copyPixelsToBuffer (Buffer dst)

Copy the bitmap's pixels into the specified buffer (allocated by the caller). An exception is thrown if the buffer is not large enough to hold all of the pixels (taking into account the number of bytes per pixel) or if the Buffer subclass is not one of the support types (ByteBuffer, ShortBuffer, IntBuffer).

The content of the bitmap is copied into the buffer as-is. This means that if this bitmap stores its pixels pre-multiplied (see isPremultiplied(), the values in the buffer will also be pre-multiplied.

After this method returns, the current position of the buffer is updated: the position is incremented by the number of elements written in the buffer.

createBitmap

Bitmap createBitmap (Bitmap source, 
                int x, 
                int y, 
                int width, 
                int height)

Returns an immutable bitmap from the specified subset of the source bitmap. The new bitmap may be the same object as source, or a copy may have been made. It is initialized with the same density as the original bitmap.

createBitmap

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. Its initial density is as per getDensity().

createBitmap

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. The new bitmap may be the same object as source, or a copy may have been made. It is initialized with the same density as the original bitmap. If the source bitmap is immutable and the requested subset is the same as the source bitmap itself, then the source bitmap is returned and no new bitmap is created.

createBitmap

Bitmap createBitmap (Bitmap src)

Returns an immutable bitmap from the source bitmap. The new bitmap may be the same object as source, or a copy may have been made. It is initialized with the same density as the original bitmap.

createBitmap

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. Its initial density is determined from the given DisplayMetrics.

createBitmap

Bitmap createBitmap (DisplayMetrics display, 
                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. Its initial density is determined from the given DisplayMetrics.

createBitmap

Bitmap createBitmap (DisplayMetrics display, 
                int width, 
                int height, 
                Bitmap.Config config)

Returns a mutable bitmap with the specified width and height. Its initial density is determined from the given DisplayMetrics.

createBitmap

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. Its initial density is as per getDensity().

createBitmap

Bitmap createBitmap (int width, 
                int height, 
                Bitmap.Config config)

Returns a mutable bitmap with the specified width and height. Its initial density is as per getDensity().

createScaledBitmap

Bitmap createScaledBitmap (Bitmap src, 
                int dstWidth, 
                int dstHeight, 
                boolean filter)

Creates a new bitmap, scaled from an existing bitmap, when possible. If the specified width and height are the same as the current width and height of the source bitmap, the source bitmap is returned and no new bitmap is created.

describeContents

int describeContents ()

No special parcel contents.

eraseColor

void eraseColor (int c)

Fills the bitmap's pixels with the specified Color.

extractAlpha

Bitmap extractAlpha ()

Returns a new bitmap that captures the alpha values of the original. This may be drawn with Canvas.drawBitmap(), where the color(s) will be taken from the paint that is passed to the draw call.

extractAlpha

Bitmap extractAlpha (Paint paint, 
                int[] offsetXY)

Returns a new bitmap that captures the alpha values of the original. These values may be affected by the optional Paint parameter, which can contain its own alpha, and may also contain a MaskFilter which could change the actual dimensions of the resulting bitmap (e.g. a blur maskfilter might enlarge the resulting bitmap). If offsetXY is not null, it returns the amount to offset the returned bitmap so that it will logically align with the original. For example, if the paint contains a blur of radius 2, then offsetXY[] would contains -2, -2, so that drawing the alpha bitmap offset by (-2, -2) and then drawing the original would result in the blur visually aligning with the original.

The initial density of the returned bitmap is the same as the original's.

getAllocationByteCount

int getAllocationByteCount ()

Returns the size of the allocated memory used to store this bitmap's pixels.

This can be larger than the result of getByteCount() if a bitmap is reused to decode other bitmaps of smaller size, or by manual reconfiguration. See reconfigure(int, int, Config), setWidth(int), setHeight(int), setConfig(Bitmap.Config), and BitmapFactory.Options.inBitmap. If a bitmap is not modified in this way, this value will be the same as that returned by getByteCount().

This value will not change over the lifetime of a Bitmap.

getByteCount

int getByteCount ()

Returns the minimum number of bytes that can be used to store this bitmap's pixels.

As of KITKAT, the result of this method can no longer be used to determine memory usage of a bitmap. See getAllocationByteCount().

getConfig

Bitmap.Config getConfig ()

If the bitmap's internal config is in one of the public formats, return that config, otherwise return null.

getDensity

int getDensity ()

Returns the density for this bitmap.

The default density is the same density as the current display, unless the current application does not support different screen densities in which case it is DENSITY_DEFAULT. Note that compatibility mode is determined by the application that was initially loaded into a process -- applications that share the same process should all have the same compatibility, or ensure they explicitly set the density of their bitmaps appropriately.

getGenerationId

int getGenerationId ()

Returns the generation ID of this bitmap. The generation ID changes whenever the bitmap is modified. This can be used as an efficient way to check if a bitmap has changed.

getHeight

int getHeight ()

Returns the bitmap's height

getNinePatchChunk

byte[] getNinePatchChunk ()

Returns an optional array of private data, used by the UI system for some bitmaps. Not intended to be called by applications.

getPixel

int getPixel (int x, 
                int y)

Returns the Color at the specified location. Throws an exception if x or y are out of bounds (negative or >= to the width or height respectively). The returned color is a non-premultiplied ARGB value.

getPixels

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. Each value is a packed int representing a Color. The stride parameter allows the caller to allow for gaps in the returned pixels array between rows. For normal packed results, just pass width for the stride value. The returned colors are non-premultiplied ARGB values.

getRowBytes

int getRowBytes ()

Return the number of bytes between rows in the bitmap's pixels. Note that this refers to the pixels as stored natively by the bitmap. If you call getPixels() or setPixels(), then the pixels are uniformly treated as 32bit values, packed according to the Color class.

As of KITKAT, this method should not be used to calculate the memory usage of the bitmap. Instead, see getAllocationByteCount().

getScaledHeight

int getScaledHeight (int targetDensity)

Convenience method that returns the height of this bitmap divided by the density scale factor.

getScaledHeight

int getScaledHeight (Canvas canvas)

Convenience for calling getScaledHeight(int) with the target density of the given Canvas.

getScaledHeight

int getScaledHeight (DisplayMetrics metrics)

Convenience for calling getScaledHeight(int) with the target density of the given DisplayMetrics.

getScaledWidth

int getScaledWidth (int targetDensity)

Convenience method that returns the width of this bitmap divided by the density scale factor.

getScaledWidth

int getScaledWidth (DisplayMetrics metrics)

Convenience for calling getScaledWidth(int) with the target density of the given DisplayMetrics.

getScaledWidth

int getScaledWidth (Canvas canvas)

Convenience for calling getScaledWidth(int) with the target density of the given Canvas.

getWidth

int getWidth ()

Returns the bitmap's width

hasAlpha

boolean hasAlpha ()

Returns true if the bitmap's config supports per-pixel alpha, and if the pixels may contain non-opaque alpha values. For some configs, this is always false (e.g. RGB_565), since they do not support per-pixel alpha. However, for configs that do, the bitmap may be flagged to be known that all of its pixels are opaque. In this case hasAlpha() will also return false. If a config such as ARGB_8888 is not so flagged, it will return true by default.

hasMipMap

boolean hasMipMap ()

Indicates whether the renderer responsible for drawing this bitmap should attempt to use mipmaps when this bitmap is drawn scaled down. If you know that you are going to draw this bitmap at less than 50% of its original size, you may be able to obtain a higher quality This property is only a suggestion that can be ignored by the renderer. It is not guaranteed to have any effect.

isMutable

boolean isMutable ()

Returns true if the bitmap is marked as mutable (i.e. can be drawn into)

isPremultiplied

boolean isPremultiplied ()

Indicates whether pixels stored in this bitmaps are stored pre-multiplied. When a pixel is pre-multiplied, the RGB components have been multiplied by the alpha component. For instance, if the original color is a 50% translucent red (128, 255, 0, 0), the pre-multiplied form is (128, 128, 0, 0).

This method always returns false if getConfig() is RGB_565.

The return value is undefined if getConfig() is ALPHA_8.

This method only returns true if hasAlpha() returns true. A bitmap with no alpha channel can be used both as a pre-multiplied and as a non pre-multiplied bitmap.

Only pre-multiplied bitmaps may be drawn by the view system or Canvas. If a non-pre-multiplied bitmap with an alpha channel is drawn to a Canvas, a RuntimeException will be thrown.

isRecycled

boolean isRecycled ()

Returns true if this bitmap has been recycled. If so, then it is an error to try to access its pixels, and the bitmap will not draw.

prepareToDraw

void prepareToDraw ()

Rebuilds any caches associated with the bitmap that are used for drawing it. In the case of purgeable bitmaps, this call will attempt to ensure that the pixels have been decoded. If this is called on more than one bitmap in sequence, the priority is given in LRU order (i.e. the last bitmap called will be given highest priority). For bitmaps with no associated caches, this call is effectively a no-op, and therefore is harmless.

reconfigure

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. Bitmap pixel data is not re-initialized for the new configuration.

This method can be used to avoid allocating a new bitmap, instead reusing an existing bitmap's allocation for a new configuration of equal or lesser size. If the Bitmap's allocation isn't large enough to support the new configuration, an IllegalArgumentException will be thrown and the bitmap will not be modified.

The result of getByteCount() will reflect the new configuration, while getAllocationByteCount() will reflect that of the initial configuration.

Note: This may change this result of hasAlpha(). When converting to 565, the new bitmap will always be considered opaque. When converting from 565, the new bitmap will be considered non-opaque, and will respect the value set by setPremultiplied().

WARNING: This method should NOT be called on a bitmap currently in use by the view system, Canvas, or the AndroidBitmap NDK API. It does not make guarantees about how the underlying pixel buffer is remapped to the new config, just that the allocation is reused. Additionally, the view system does not account for bitmap properties being modifying during use, e.g. while attached to drawables.

In order to safely ensure that a Bitmap is no longer in use by the View system it is necessary to wait for a draw pass to occur after invalidate()'ing any view that had previously drawn the Bitmap in the last draw pass due to hardware acceleration's caching of draw commands. As an example, here is how this can be done for an ImageView:

      ImageView myImageView = ...;
      final Bitmap myBitmap = ...;
      myImageView.setImageDrawable(null);
      myImageView.post(new Runnable() {
          public void run() {
              // myBitmap is now no longer in use by the ImageView
              // and can be safely reconfigured.
              myBitmap.reconfigure(...);
          }
      });
 

recycle

void recycle ()

Free the native object associated with this bitmap, and clear the reference to the pixel data. This will not free the pixel data synchronously; it simply allows it to be garbage collected if there are no other references. The bitmap is marked as "dead", meaning it will throw an exception if getPixels() or setPixels() is called, and will draw nothing. This operation cannot be reversed, so it should only be called if you are sure there are no further uses for the bitmap. This is an advanced call, and normally need not be called, since the normal GC process will free up this memory when there are no more references to this bitmap.

sameAs

boolean sameAs (Bitmap other)

Given another bitmap, return true if it has the same dimensions, config, and pixel data as this bitmap. If any of those differ, return false. If other is null, return false.

setConfig

void setConfig (Bitmap.Config config)

Convenience method for calling reconfigure(int, int, Config) with the current height and width.

WARNING: this method should not be used on bitmaps currently used by the view system, see reconfigure(int, int, Config) for more details.

setDensity

void setDensity (int density)

Specifies the density for this bitmap. When the bitmap is drawn to a Canvas that also has a density, it will be scaled appropriately.

setHasAlpha

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). Note, for some configs (e.g. RGB_565) this call is ignored, since it does not support per-pixel alpha values. This is meant as a drawing hint, as in some cases a bitmap that is known to be opaque can take a faster drawing case than one that may have non-opaque per-pixel alpha values.

setHasMipMap

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. If you know that you are going to draw this bitmap at less than 50% of its original size, you may be able to obtain a higher quality by turning this property on. Note that if the renderer respects this hint it might have to allocate extra memory to hold the mipmap levels for this bitmap. This property is only a suggestion that can be ignored by the renderer. It is not guaranteed to have any effect.

setHeight

void setHeight (int height)

Convenience method for calling reconfigure(int, int, Config) with the current width and config.

WARNING: this method should not be used on bitmaps currently used by the view system, see reconfigure(int, int, Config) for more details.

setPixel

void setPixel (int x, 
                int y, 
                int color)

Write the specified Color into the bitmap (assuming it is mutable) at the x,y coordinate. The color must be a non-premultiplied ARGB value.

setPixels

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. Each element in the array is a packed int prepresenting a non-premultiplied ARGB Color.

setPremultiplied

void setPremultiplied (boolean premultiplied)

Sets whether the bitmap should treat its data as pre-multiplied.

Bitmaps are always treated as pre-multiplied by the view system and Canvas for performance reasons. Storing un-pre-multiplied data in a Bitmap (through setPixel(int, int, int), setPixels(int[], int, int, int, int, int, int), or BitmapFactory.Options.inPremultiplied) can lead to incorrect blending if drawn by the framework.

This method will not affect the behavior of a bitmap without an alpha channel, or if hasAlpha() returns false.

Calling createBitmap(Bitmap) or createScaledBitmap(Bitmap, int, int, boolean) with a source Bitmap whose colors are not pre-multiplied may result in a RuntimeException, since those functions require drawing the source, which is not supported for un-pre-multiplied Bitmaps.

setWidth

void setWidth (int width)

Convenience method for calling reconfigure(int, int, Config) with the current height and config.

WARNING: this method should not be used on bitmaps currently used by the view system, see reconfigure(int, int, Config) for more details.

writeToParcel

void writeToParcel (Parcel p, 
                int flags)

Write the bitmap and its pixels to the parcel. The bitmap can be rebuilt from the parcel by calling CREATOR.createFromParcel().