Imagepublic abstract class Image extends Object implements AutoCloseableA single complete image buffer to use with a media source such as a
{@link MediaCodec} or a
{@link android.hardware.camera2.CameraDevice CameraDevice}.
This class allows for efficient direct application access to the pixel
data of the Image through one or more
{@link java.nio.ByteBuffer ByteBuffers}. Each buffer is encapsulated in a
{@link Plane} that describes the layout of the pixel data in that plane. Due
to this direct access, and unlike the {@link android.graphics.Bitmap Bitmap} class,
Images are not directly usable as 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 {@link ImageReader} class to read out Images
from various media sources, not closing old Image objects will prevent the
availability of new Images once
{@link ImageReader#getMaxImages the maximum outstanding image count} is
reached. When this happens, the function acquiring new Images will typically
throw an {@link IllegalStateException}. |
| Fields Summary |
|---|
| private android.graphics.Rect | mCropRect |
| Constructors Summary |
|---|
protected Image()
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| Methods Summary |
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| public abstract void | close()Free up this frame for reuse.
After calling this method, calling any methods on this {@code Image} will
result in an {@link IllegalStateException}, and attempting to read from
{@link ByteBuffer ByteBuffers} returned by an earlier
{@link Plane#getBuffer} call will have undefined behavior.
| | public android.graphics.Rect | getCropRect()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.
if (mCropRect == null) {
return new Rect(0, 0, getWidth(), getHeight());
} else {
return new Rect(mCropRect); // return a copy
}
| | public abstract int | getFormat()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 in ByteBuffer.
The format is one of the values from
{@link android.graphics.ImageFormat ImageFormat}. The mapping between the
formats and the planes is as follows:
| Format |
Plane count |
Layout details |
| {@link android.graphics.ImageFormat#JPEG JPEG} |
1 |
Compressed data, so row and pixel strides are 0. To uncompress, use
{@link android.graphics.BitmapFactory#decodeByteArray BitmapFactory#decodeByteArray}.
|
| {@link android.graphics.ImageFormat#YUV_420_888 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. |
| {@link android.graphics.ImageFormat#RAW_SENSOR 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
{@link android.hardware.camera2.CameraDevice CameraDevice}.
|
| | public abstract int | getHeight()The height of the image in pixels. For formats where some color channels
are subsampled, this is the height of the largest-resolution plane.
| | public abstract android.media.Image$Plane[] | getPlanes()Get the array of pixel planes for this Image. The number of planes is
determined by the format of the Image.
| | public abstract long | getTimestamp()Get the timestamp associated with this frame.
The timestamp is measured in nanoseconds, and is monotonically
increasing. However, the zero point and whether the timestamp can be
compared against other sources of time or images depend on the source of
this image.
| | public abstract int | getWidth()The width of the image in pixels. For formats where some color channels
are subsampled, this is the width of the largest-resolution plane.
| | public void | setCropRect(android.graphics.Rect cropRect)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.
if (cropRect != null) {
cropRect = new Rect(cropRect); // make a copy
cropRect.intersect(0, 0, getWidth(), getHeight());
}
mCropRect = cropRect;
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