Image
abstract class Image : AutoCloseable
| kotlin.Any | |
| ↳ | android.media.Image |
A single complete image buffer to use with a media source such as a MediaCodec or a CameraDevice.
This class allows for efficient direct application access to the pixel data of the Image through one or more ByteBuffers. Each buffer is encapsulated in a Plane that describes the layout of the pixel data in that plane. Due to this direct access, and unlike the Bitmap class, Images are not directly usable as UI resources.
Since Images are often directly produced or consumed by hardware components, they are a limited resource shared across the system, and should be closed as soon as they are no longer needed.
For example, when using the ImageReader class to read out Images from various media sources, not closing old Image objects will prevent the availability of new Images once the maximum outstanding image count is reached. When this happens, the function acquiring new Images will typically throw an IllegalStateException.
Summary
| Nested classes | |
|---|---|
| abstract |
A single color plane of image data. |
| Public methods | |
|---|---|
| abstract Unit |
close()Free up this frame for reuse. |
| open Rect! |
Get the crop rectangle associated with this frame. |
| open Int |
Get the dataspace associated with this frame. |
| open SyncFence |
getFence()Get the SyncFence object associated with this frame. |
| abstract Int |
Get the format for this image. |
| open HardwareBuffer? |
Get the |
| abstract Int |
The height of the image in pixels. |
| abstract Array<Image.Plane!>! |
Get the array of pixel planes for this Image. |
| abstract Long |
Get the timestamp associated with this frame. |
| abstract Int |
getWidth()The width of the image in pixels. |
| open Unit |
setCropRect(cropRect: Rect!)Set the crop rectangle associated with this frame. |
| open Unit |
setDataSpace(dataSpace: Int)Set the dataspace associated with this frame. |
| open Unit |
Set the fence file descriptor with this frame. |
| open Unit |
setTimestamp(timestamp: Long)Set the timestamp associated with this frame. |
Public methods
close
abstract fun close(): Unit
Free up this frame for reuse.
After calling this method, calling any methods on this Image will result in an IllegalStateException, and attempting to read from or write to ByteBuffers returned by an earlier Plane#getBuffer call will have undefined behavior. If the image was obtained from ImageWriter via ImageWriter#dequeueInputImage(), after calling this method, any image data filled by the application will be lost and the image will be returned to ImageWriter for reuse. Images given to queueInputImage() are automatically closed.
| Exceptions | |
|---|---|
java.lang.Exception |
if this resource cannot be closed |
getCropRect
open fun getCropRect(): Rect!
Get the crop rectangle associated with this frame.
The crop rectangle specifies the region of valid pixels in the image, using coordinates in the largest-resolution plane.
getDataSpace
open fun getDataSpace(): Int
Get the dataspace associated with this frame.
getFence
open fun getFence(): SyncFence
Get the SyncFence object associated with this frame.
This function returns an invalid SyncFence after getPlanes() on the image dequeued from ImageWriter via ImageWriter#dequeueInputImage().
| Return | |
|---|---|
SyncFence |
The SyncFence for this frame. This value cannot be null. |
| Exceptions | |
|---|---|
java.io.IOException |
if there is an error when a SyncFence object returns. |
See Also
getFormat
abstract fun getFormat(): Int
Get the format for this image. This format determines the number of ByteBuffers needed to represent the image, and the general layout of the pixel data in each ByteBuffer.
The format is one of the values from ImageFormat, PixelFormat, or HardwareBuffer. The mapping between the formats and the planes is as follows (any formats not listed will have 1 plane):
| Format | Plane count | Layout details |
|---|---|---|
JPEG |
1 | Compressed data, so row and pixel strides are 0. To uncompress, use android.graphics.BitmapFactory#decodeByteArray. |
YUV_420_888 |
3 | A luminance plane followed by the Cb and Cr chroma planes. The chroma planes have half the width and height of the luminance plane (4:2:0 subsampling). Each pixel sample in each plane has 8 bits. Each plane has its own row stride and pixel stride. |
YUV_422_888 |
3 | A luminance plane followed by the Cb and Cr chroma planes. The chroma planes have half the width and the full height of the luminance plane (4:2:2 subsampling). Each pixel sample in each plane has 8 bits. Each plane has its own row stride and pixel stride. |
YUV_444_888 |
3 | A luminance plane followed by the Cb and Cr chroma planes. The chroma planes have the same width and height as that of the luminance plane (4:4:4 subsampling). Each pixel sample in each plane has 8 bits. Each plane has its own row stride and pixel stride. |
FLEX_RGB_888 |
3 | A R (red) plane followed by the G (green) and B (blue) planes. All planes have the same widths and heights. Each pixel sample in each plane has 8 bits. Each plane has its own row stride and pixel stride. |
FLEX_RGBA_8888 |
4 | A R (red) plane followed by the G (green), B (blue), and A (alpha) planes. All planes have the same widths and heights. Each pixel sample in each plane has 8 bits. Each plane has its own row stride and pixel stride. |
RAW_SENSOR |
1 | A single plane of raw sensor image data, with 16 bits per color sample. The details of the layout need to be queried from the source of the raw sensor data, such as CameraDevice. |
RAW_PRIVATE |
1 | A single plane of raw sensor image data of private layout. The details of the layout is implementation specific. Row stride and pixel stride are undefined for this format. Calling Plane#getRowStride() or Plane#getPixelStride() on RAW_PRIVATE image will cause UnSupportedOperationException being thrown. |
HEIC |
1 | Compressed data, so row and pixel strides are 0. To uncompress, use android.graphics.BitmapFactory#decodeByteArray. |
YCBCR_P010 |
3 | P010 is a 4:2:0 YCbCr semiplanar format comprised of a WxH Y plane followed by a Wx(H/2) Cb and Cr planes. Each sample is represented by a 16-bit little-endian value, with the lower 6 bits set to zero. Since this is guaranteed to be a semi-planar format, the Cb plane can also be treated as an interleaved Cb/Cr plane. |
getHardwareBuffer
open fun getHardwareBuffer(): HardwareBuffer?
Get the HardwareBuffer handle of the input image intended for GPU and/or hardware access.
The returned HardwareBuffer shall not be used after Image.close() has been called.
| Return | |
|---|---|
HardwareBuffer? |
the HardwareBuffer associated with this Image or null if this Image doesn't support this feature. (Unsupported use cases include Image instances obtained through MediaCodec, and on versions prior to Android P, ImageWriter). |
getHeight
abstract fun getHeight(): Int
The height of the image in pixels. For formats where some color channels are subsampled, this is the height of the largest-resolution plane.
getPlanes
abstract fun getPlanes(): Array<Image.Plane!>!
Get the array of pixel planes for this Image. The number of planes is determined by the format of the Image. The application will get an empty array if the image format is PRIVATE, because the image pixel data is not directly accessible. The application can check the image format by calling Image#getFormat().
getTimestamp
abstract fun getTimestamp(): Long
Get the timestamp associated with this frame.
The timestamp is measured in nanoseconds, and is normally monotonically increasing. The timestamps for the images from different sources may have different timebases therefore may not be comparable. The specific meaning and timebase of the timestamp depend on the source providing images. See Camera, CameraDevice, MediaPlayer and MediaCodec for more details.
getWidth
abstract fun getWidth(): Int
The width of the image in pixels. For formats where some color channels are subsampled, this is the width of the largest-resolution plane.
setCropRect
open fun setCropRect(cropRect: Rect!): Unit
Set the crop rectangle associated with this frame.
The crop rectangle specifies the region of valid pixels in the image, using coordinates in the largest-resolution plane.
setDataSpace
open fun setDataSpace(dataSpace: Int): Unit
Set the dataspace associated with this frame.
If dataspace for an image is not set, dataspace value depends on android.view.Surface that is provided in the ImageWriter constructor.
setFence
open fun setFence(fence: SyncFence): Unit
Set the fence file descriptor with this frame.
| Parameters | |
|---|---|
fence |
SyncFence: The fence file descriptor to be set for this frame. This value cannot be null. |
| Exceptions | |
|---|---|
java.io.IOException |
if there is an error when setting a SyncFence. |
See Also
setTimestamp
open fun setTimestamp(timestamp: Long): Unit
Set the timestamp associated with this frame.
The timestamp is measured in nanoseconds, and is normally monotonically increasing. The timestamps for the images from different sources may have different timebases therefore may not be comparable. The specific meaning and timebase of the timestamp depend on the source providing images. See Camera, CameraDevice, MediaPlayer and MediaCodec for more details.
For images dequeued from ImageWriter via ImageWriter#dequeueInputImage(), it's up to the application to set the timestamps correctly before sending them back to the ImageWriter, or the timestamp will be generated automatically when queueInputImage() is called.
| Parameters | |
|---|---|
timestamp |
Long: The timestamp to be set for this image. |