I try to read an image from sdcard (in emulator) and then create a Bitmap image with the
BitmapFactory.decodeByteArray
method. I set the options:
options.inPrefferedConfig = Bitmap.Config.ARGB_8888
options.inDither = false
Then I extract the pixels into a ByteBuffer.
ByteBuffer buffer = ByteBuffer.allocateDirect(width*height*4)
bitmap.copyPixelsToBuffer(buffer)
I use this ByteBuffer then in the JNI to convert it into RGB format and want to calculate on it.
But always I get false data - I test without modifying the ByteBuffer. Only thing I do is to put it into the native method into JNI. Then cast it into a unsigned char* and convert it back into a ByteBuffer before returning it back to Java.
unsigned char* buffer = (unsinged char*)(env->GetDirectBufferAddress(byteBuffer))
jobject returnByteBuffer = env->NewDirectByteBuffer(buffer, length)
Before displaying the image I get data back with
bitmap.copyPixelsFromBuffer( buffer )
But then it has wrong data in it.
My Question is if this is because the image is internally converted into RGB 565 or what is wrong here?
.....
Have an answer for it:
->>> yes, it is converted internally to RGB565.
Does anybody know how to create such an bitmap image from PNG with ARGB8888 pixel format?
If anybody has an idea, it would be great!
An ARGB_8888 Bitmap (on pre Honeycomb versions) is natively stored in the RGBA format.
So the alpha channel is moved at the end. You should take this into account when accessing a Bitmap's pixels natively.
I assume you are writing code for a version of Android lower than 3.2 (API level < 12), because since then the behavior of the methods
BitmapFactory.decodeFile(pathToImage);
BitmapFactory.decodeFile(pathToImage, opt);
bitmapObject.createScaledBitmap(bitmap, desiredWidth, desiredHeight, false /*filter?*/);
has changed.
On older platforms (API level < 12) the BitmapFactory.decodeFile(..) methods try to return a Bitmap with RGB_565 config by default, if they can't find any alpha, which lowers the quality of an iamge. This is still ok, because you can enforce an ARGB_8888 bitmap using
options.inPrefferedConfig = Bitmap.Config.ARGB_8888
options.inDither = false
The real problem comes when each pixel of your image has an alpha value of 255 (i.e. completely opaque). In that case the Bitmap's flag 'hasAlpha' is set to false, even though your Bitmap has ARGB_8888 config. If your *.png-file had at least one real transparent pixel, this flag would have been set to true and you wouldn't have to worry about anything.
So when you want to create a scaled Bitmap using
bitmapObject.createScaledBitmap(bitmap, desiredWidth, desiredHeight, false /*filter?*/);
the method checks whether the 'hasAlpha' flag is set to true or false, and in your case it is set to false, which results in obtaining a scaled Bitmap, which was automatically converted to the RGB_565 format.
Therefore on API level >= 12 there is a public method called
public void setHasAlpha (boolean hasAlpha);
which would have solved this issue. So far this was just an explanation of the problem.
I did some research and noticed that the setHasAlpha method has existed for a long time and it's public, but has been hidden (#hide annotation). Here is how it is defined on Android 2.3:
/**
* 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 ignore, 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.
*
* #hide
*/
public void setHasAlpha(boolean hasAlpha) {
nativeSetHasAlpha(mNativeBitmap, hasAlpha);
}
Now here is my solution proposal. It does not involve any copying of bitmap data:
Checked at runtime using java.lang.Reflect if the current
Bitmap implementation has a public 'setHasAplha' method.
(According to my tests it works perfectly since API level 3, and i haven't tested lower versions, because JNI wouldn't work). You may have problems if a manufacturer has explicitly made it private, protected or deleted it.
Call the 'setHasAlpha' method for a given Bitmap object using JNI.
This works perfectly, even for private methods or fields. It is official that JNI does not check whether you are violating the access control rules or not.
Source: http://java.sun.com/docs/books/jni/html/pitfalls.html (10.9)
This gives us great power, which should be used wisely. I wouldn't try modifying a final field, even if it would work (just to give an example). And please note this is just a workaround...
Here is my implementation of all necessary methods:
JAVA PART:
// NOTE: this cannot be used in switch statements
private static final boolean SETHASALPHA_EXISTS = setHasAlphaExists();
private static boolean setHasAlphaExists() {
// get all puplic Methods of the class Bitmap
java.lang.reflect.Method[] methods = Bitmap.class.getMethods();
// search for a method called 'setHasAlpha'
for(int i=0; i<methods.length; i++) {
if(methods[i].getName().contains("setHasAlpha")) {
Log.i(TAG, "method setHasAlpha was found");
return true;
}
}
Log.i(TAG, "couldn't find method setHasAlpha");
return false;
}
private static void setHasAlpha(Bitmap bitmap, boolean value) {
if(bitmap.hasAlpha() == value) {
Log.i(TAG, "bitmap.hasAlpha() == value -> do nothing");
return;
}
if(!SETHASALPHA_EXISTS) { // if we can't find it then API level MUST be lower than 12
// couldn't find the setHasAlpha-method
// <-- provide alternative here...
return;
}
// using android.os.Build.VERSION.SDK to support API level 3 and above
// use android.os.Build.VERSION.SDK_INT to support API level 4 and above
if(Integer.valueOf(android.os.Build.VERSION.SDK) <= 11) {
Log.i(TAG, "BEFORE: bitmap.hasAlpha() == " + bitmap.hasAlpha());
Log.i(TAG, "trying to set hasAplha to true");
int result = setHasAlphaNative(bitmap, value);
Log.i(TAG, "AFTER: bitmap.hasAlpha() == " + bitmap.hasAlpha());
if(result == -1) {
Log.e(TAG, "Unable to access bitmap."); // usually due to a bug in the own code
return;
}
} else { //API level >= 12
bitmap.setHasAlpha(true);
}
}
/**
* Decodes a Bitmap from the SD card
* and scales it if necessary
*/
public Bitmap decodeBitmapFromFile(String pathToImage, int pixels_limit) {
Bitmap bitmap;
Options opt = new Options();
opt.inDither = false; //important
opt.inPreferredConfig = Bitmap.Config.ARGB_8888;
bitmap = BitmapFactory.decodeFile(pathToImage, opt);
if(bitmap == null) {
Log.e(TAG, "unable to decode bitmap");
return null;
}
setHasAlpha(bitmap, true); // if necessary
int numOfPixels = bitmap.getWidth() * bitmap.getHeight();
if(numOfPixels > pixels_limit) { //image needs to be scaled down
// ensures that the scaled image uses the maximum of the pixel_limit while keeping the original aspect ratio
// i use: private static final int pixels_limit = 1280*960; //1,3 Megapixel
imageScaleFactor = Math.sqrt((double) pixels_limit / (double) numOfPixels);
Bitmap scaledBitmap = Bitmap.createScaledBitmap(bitmap,
(int) (imageScaleFactor * bitmap.getWidth()), (int) (imageScaleFactor * bitmap.getHeight()), false);
bitmap.recycle();
bitmap = scaledBitmap;
Log.i(TAG, "scaled bitmap config: " + bitmap.getConfig().toString());
Log.i(TAG, "pixels_limit = " + pixels_limit);
Log.i(TAG, "scaled_numOfpixels = " + scaledBitmap.getWidth()*scaledBitmap.getHeight());
setHasAlpha(bitmap, true); // if necessary
}
return bitmap;
}
Load your lib and declare the native method:
static {
System.loadLibrary("bitmaputils");
}
private static native int setHasAlphaNative(Bitmap bitmap, boolean value);
Native section ('jni' folder)
Android.mk:
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := bitmaputils
LOCAL_SRC_FILES := bitmap_utils.c
LOCAL_LDLIBS := -llog -ljnigraphics -lz -ldl -lgcc
include $(BUILD_SHARED_LIBRARY)
bitmapUtils.c:
#include <jni.h>
#include <android/bitmap.h>
#include <android/log.h>
#define LOG_TAG "BitmapTest"
#define Log_i(...) __android_log_print(ANDROID_LOG_INFO,LOG_TAG,__VA_ARGS__)
#define Log_e(...) __android_log_print(ANDROID_LOG_ERROR,LOG_TAG,__VA_ARGS__)
// caching class and method IDs for a faster subsequent access
static jclass bitmap_class = 0;
static jmethodID setHasAlphaMethodID = 0;
jint Java_com_example_bitmaptest_MainActivity_setHasAlphaNative(JNIEnv * env, jclass clazz, jobject bitmap, jboolean value) {
AndroidBitmapInfo info;
void* pixels;
if (AndroidBitmap_getInfo(env, bitmap, &info) < 0) {
Log_e("Failed to get Bitmap info");
return -1;
}
if (info.format != ANDROID_BITMAP_FORMAT_RGBA_8888) {
Log_e("Incompatible Bitmap format");
return -1;
}
if (AndroidBitmap_lockPixels(env, bitmap, &pixels) < 0) {
Log_e("Failed to lock the pixels of the Bitmap");
return -1;
}
// get class
if(bitmap_class == NULL) { //initializing jclass
// NOTE: The class Bitmap exists since API level 1, so it just must be found.
bitmap_class = (*env)->GetObjectClass(env, bitmap);
if(bitmap_class == NULL) {
Log_e("bitmap_class == NULL");
return -2;
}
}
// get methodID
if(setHasAlphaMethodID == NULL) { //initializing jmethodID
// NOTE: If this fails, because the method could not be found the App will crash.
// But we only call this part of the code if the method was found using java.lang.Reflect
setHasAlphaMethodID = (*env)->GetMethodID(env, bitmap_class, "setHasAlpha", "(Z)V");
if(setHasAlphaMethodID == NULL) {
Log_e("methodID == NULL");
return -2;
}
}
// call java instance method
(*env)->CallVoidMethod(env, bitmap, setHasAlphaMethodID, value);
// if an exception was thrown we could handle it here
if ((*env)->ExceptionOccurred(env)) {
(*env)->ExceptionDescribe(env);
(*env)->ExceptionClear(env);
Log_e("calling setHasAlpha threw an exception");
return -2;
}
if(AndroidBitmap_unlockPixels(env, bitmap) < 0) {
Log_e("Failed to unlock the pixels of the Bitmap");
return -1;
}
return 0; // success
}
That's it. We are done. I've posted the whole code for copy-and-paste purposes.
The actual code isn't that big, but making all these paranoid error checks makes it a lot bigger. I hope this could be helpful to anyone.
Related
I need to do some real-time image processing with the camera preview data, such as face detection which is a c++ library, and then display the processed preview with face labeled on screen.
I have read http://nezarobot.blogspot.com/2016/03/android-surfacetexture-camera2-opencv.html and Eddy Talvala's answer from Android camera2 API - Display processed frame in real time. Following the two webpages, I managed to build the app(no calling the face detection lib, only trying to display preview using ANativeWindow), but everytime I run this app on Google Pixel - 7.1.0 - API 25 running on Genymotion, the app always collapses throwing the following log
08-28 14:23:09.598 2099-2127/tau.camera2demo A/libc: Fatal signal 11 (SIGSEGV), code 2, fault addr 0xd3a96000 in tid 2127 (CAMERA2)
[ 08-28 14:23:09.599 117: 117 W/ ]
debuggerd: handling request: pid=2099 uid=10067 gid=10067 tid=2127
I googled this but no answer found.
The whole project on Github:https://github.com/Fung-yuantao/android-camera2demo
Here is the key code(I think).
Code in Camera2Demo.java:
private void startPreview(CameraDevice camera) throws CameraAccessException {
SurfaceTexture texture = mPreviewView.getSurfaceTexture();
// to set PREVIEW size
texture.setDefaultBufferSize(mPreviewSize.getWidth(),mPreviewSize.getHeight());
surface = new Surface(texture);
try {
// to set request for PREVIEW
mPreviewBuilder = camera.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
} catch (CameraAccessException e) {
e.printStackTrace();
}
mImageReader = ImageReader.newInstance(mImageWidth, mImageHeight, ImageFormat.YUV_420_888, 2);
mImageReader.setOnImageAvailableListener(mOnImageAvailableListener,mHandler);
mPreviewBuilder.addTarget(mImageReader.getSurface());
//output Surface
List<Surface> outputSurfaces = new ArrayList<>();
outputSurfaces.add(mImageReader.getSurface());
/*camera.createCaptureSession(
Arrays.asList(surface, mImageReader.getSurface()),
mSessionStateCallback, mHandler);
*/
camera.createCaptureSession(outputSurfaces, mSessionStateCallback, mHandler);
}
private CameraCaptureSession.StateCallback mSessionStateCallback = new CameraCaptureSession.StateCallback() {
#Override
public void onConfigured(CameraCaptureSession session) {
try {
updatePreview(session);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
#Override
public void onConfigureFailed(CameraCaptureSession session) {
}
};
private void updatePreview(CameraCaptureSession session)
throws CameraAccessException {
mPreviewBuilder.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_AUTO);
session.setRepeatingRequest(mPreviewBuilder.build(), null, mHandler);
}
private ImageReader.OnImageAvailableListener mOnImageAvailableListener = new ImageReader.OnImageAvailableListener() {
#Override
public void onImageAvailable(ImageReader reader) {
// get the newest frame
Image image = reader.acquireNextImage();
if (image == null) {
return;
}
// print image format
int format = reader.getImageFormat();
Log.d(TAG, "the format of captured frame: " + format);
// HERE to call jni methods
JNIUtils.display(image.getWidth(), image.getHeight(), image.getPlanes()[0].getBuffer(), surface);
//ByteBuffer buffer = image.getPlanes()[0].getBuffer();
//byte[] bytes = new byte[buffer.remaining()];
image.close();
}
};
Code in JNIUtils.java:
import android.media.Image;
import android.view.Surface;
import java.nio.ByteBuffer;
public class JNIUtils {
// TAG for JNIUtils class
private static final String TAG = "JNIUtils";
// Load native library.
static {
System.loadLibrary("native-lib");
}
public static native void display(int srcWidth, int srcHeight, ByteBuffer srcBuffer, Surface surface);
}
Code in native-lib.cpp:
#include <jni.h>
#include <string>
#include <android/log.h>
//#include <android/bitmap.h>
#include <android/native_window_jni.h>
#define LOGE(...) __android_log_print(ANDROID_LOG_ERROR, "Camera2Demo", __VA_ARGS__)
extern "C" {
JNIEXPORT jstring JNICALL Java_tau_camera2demo_JNIUtils_display(
JNIEnv *env,
jobject obj,
jint srcWidth,
jint srcHeight,
jobject srcBuffer,
jobject surface) {
/*
uint8_t *srcLumaPtr = reinterpret_cast<uint8_t *>(env->GetDirectBufferAddress(srcBuffer));
if (srcLumaPtr == nullptr) {
LOGE("srcLumaPtr null ERROR!");
return NULL;
}
*/
ANativeWindow * window = ANativeWindow_fromSurface(env, surface);
ANativeWindow_acquire(window);
ANativeWindow_Buffer buffer;
ANativeWindow_setBuffersGeometry(window, srcWidth, srcHeight, 0/* format unchanged */);
if (int32_t err = ANativeWindow_lock(window, &buffer, NULL)) {
LOGE("ANativeWindow_lock failed with error code: %d\n", err);
ANativeWindow_release(window);
return NULL;
}
memcpy(buffer.bits, srcBuffer, srcWidth * srcHeight * 4);
ANativeWindow_unlockAndPost(window);
ANativeWindow_release(window);
return NULL;
}
}
After I commented the memcpy out, the app no longer collapses but displays nothing. So I guess the problem is now turning to how to correctly use memcpy to copy the captured/processed buffer to buffer.bits.
Update:
I change
memcpy(buffer.bits, srcBuffer, srcWidth * srcHeight * 4);
to
memcpy(buffer.bits, srcLumaPtr, srcWidth * srcHeight * 4);
the app no longer collapses and starts to display but it's displaying something strange.
As mentioned by yakobom, you're trying to copy a YUV_420_888 image directly into a RGBA_8888 destination (that's the default, if you haven't changed it). That won't work with just a memcpy.
You need to actually convert the data, and you need to ensure you don't copy too much - the sample code you have copies width*height*4 bytes, while a YUV_420_888 image takes up only stride*height*1.5 bytes (roughly). So when you copied, you were running way off the end of the buffer.
You also have to account for the stride provided at the Java level to correctly index into the buffer. This link from Microsoft has a useful diagram.
If you just care about the luminance (so grayscale output is enough), just duplicate the luminance channel into the R, G, and B channels. The pseudocode would be roughly:
uint8_t *outPtr = buffer.bits;
for (size_t y = 0; y < height; y++) {
uint8_t *rowPtr = srcLumaPtr + y * srcLumaStride;
for (size_t x = 0; x < width; x++) {
*(outPtr++) = *rowPtr;
*(outPtr++) = *rowPtr;
*(outPtr++) = *rowPtr;
*(outPtr++) = 255; // gamma for RGBA_8888
++rowPtr;
}
}
You'll need to read the srcLumaStride from the Image object (row stride of the first Plane) and pass it down via JNI as well.
Just to put it as an answer, to avoid a long chain of comments - such a crash issue may be due to improper size of bites being copied by the memcpy (UPDATE following other comments: In this case it was due to forbidden direct copy).
If you are now getting a weird image, it is probably another issue - I would suspect the image format, try to modify that.
I'm passing window buffer from native side in android app to java side.
AndroidBitmapInfo info;
void saveBufferToBitmap(JNIEnv *env, ANativeWindow_Buffer *buffer, jobject bitmap) {
void *pixels;
LOGI(10, "saving buffer to bitmap");
if (AndroidBitmap_getInfo(env, bitmap, &info) < 0) {
LOGE(10, "Failed to get bitmap info");
return;
}
if (AndroidBitmap_lockPixels(env, bitmap, &pixels) < 0) {
LOGE(10, "Failed to lock pixles for bitmap");
return;
}
int i, scan_length;
scan_length = buffer->width * 4;
memcpy(pixels, buffer->bits, buffer->width * buffer->height * 4); // 4 = (rgba)
AndroidBitmap_unlockPixels(env, bitmap);
//free(pixels); // here
}
Should i free pixels buffer in // here ? Does AndroidBitmap_lockPixels/AndroidBitmap_unlockPixels copy buffer to bitmap?
As a general rule you generally should never free a pointer that you did not create with new yourself. The library call you get the pointer from may use whatever allocation or just pass out a pointer to an internal data structure. The second is very likely in this case.
Looking at the documentation from the source:
/**
* Given a java bitmap object, attempt to lock the pixel address.
* Locking will ensure that the memory for the pixels will not move
* until the unlockPixels call, and ensure that, if the pixels had been
* previously purged, they will have been restored.
*
* If this call succeeds, it must be balanced by a call to
* AndroidBitmap_unlockPixels, after which time the address of the pixels should
* no longer be used.
*
* If this succeeds, *addrPtr will be set to the pixel address. If the call
* fails, addrPtr will be ignored.
*/
int AndroidBitmap_lockPixels(JNIEnv* env, jobject jbitmap, void** addrPtr);
Source: https://android.googlesource.com/platform/frameworks/native/+/master/include/android/bitmap.h
That tells us not do anything with pixels after AndroidBitmap_unlockPixels and definitely not free it.
I get the error that my buffer is not large enough for pixels. Any recommendations? The Bitmap b should be the same size as the gSaveBitmap that I'm trying to place its pixels into.
if(gBuffer == null)
{
Bitmap b = Bitmap.createScaledBitmap(gBitmap, mWidth, mHeight, false);
//gBuffer = ByteBuffer.allocateDirect(b.getRowBytes()*b.getHeight()*4);
ByteArrayOutputStream stream = new ByteArrayOutputStream();
b.compress(Bitmap.CompressFormat.PNG, 100, stream);
gBuffer = ByteBuffer.wrap(stream.toByteArray());
b.recycle();
}
gSaveBitmap.copyPixelsFromBuffer(gBuffer);
Update: The below code gives the exact same error without any compression involved.
if(gBuffer == null)
{
Bitmap b = Bitmap.createScaledBitmap(gBitmap, mWidth, mHeight, false);
int bytes = b.getWidth()*b.getHeight()*4;
gBuffer = ByteBuffer.allocate(bytes);
b.copyPixelsToBuffer(gBuffer);
b.recycle();
}
gSaveBitmap.copyPixelsFromBuffer(gBuffer);
Update: Solved the issue by doubling the size of gBuffer. Perhaps someone can tell me why this is the correct size. Also ... the picture is in the wrong rotation, needs rotated 90 degrees. Any ideas how the data would need to be rearranged in gBuffer?
gBuffer = ByteBuffer.allocate(b.getRowBytes()*b.getHeight()*2);
I think I might have solved this one-- take a look at the source (version 2.3.4_r1, last time Bitmap was updated on Grepcode prior to 4.4) for Bitmap::copyPixelsFromBuffer()
public void copyPixelsFromBuffer(Buffer src) {
checkRecycled("copyPixelsFromBuffer called on recycled bitmap");
int elements = src.remaining();
int shift;
if (src instanceof ByteBuffer) {
shift = 0;
} else if (src instanceof ShortBuffer) {
shift = 1;
} else if (src instanceof IntBuffer) {
shift = 2;
} else {
throw new RuntimeException("unsupported Buffer subclass");
}
long bufferBytes = (long)elements << shift;
long bitmapBytes = (long)getRowBytes() * getHeight();
if (bufferBytes < bitmapBytes) {
throw new RuntimeException("Buffer not large enough for pixels");
}
nativeCopyPixelsFromBuffer(mNativeBitmap, src);
}
The wording of the error is a bit unclear, but the code clarifies-- it means that your buffer is calculated as not having enough data to fill the pixels of your bitmap.
This is because they use the buffer's remaining() method to figure the capacity of the buffer, which takes into account the current value of its position attribute. If you call rewind() on your buffer before you invoke copyPixelsFromBuffer(), you should see the runtime exception disappear.
I found the answer for this issue :
You should always set the buffer size > bit map size since The Bitmap on different Android version always changed.
You can log the codes in below to see the buffer size & bitmap size (Android API should >= 12 to use following log)
Log.i("", "Bitmap size = " + mBitmap.getByteCount());
Log.i("", "Buffer size = " + mBuffer.capacity());
It should be worked.
Thanks,
I have an app built in Android 2.2 and I'm using inPreferredConfig() to switch a bitmap to ARGB_8888 format, however, this doesn't seem to work as when checked immediately afterwards the bitmap is still in RGB_565 format. I've tried changing it to any of the other formats and neither of those work either.
The function works fine if the phone or emulator is running Android 2.2, but anything above that fails. Does anyone know why this is happening? Is inPreferredConfig() depreciated in later Android versions?
What I'm doing:
I'm using the NDK with some C code I've found to run some image processing functions (taken from http://www.ibm.com/developerworks/opensource/tutorials/os-androidndk/section5.html). The C code expects the image format to be in ARGB_8888 and although the Android documentation says that the format should already be in 8888 by default but it's definitely in 565 so I'm very confused.
I'm guessing I could convert it in C...but I'm terrible at C so I wouldn't know where to start.
My C function:
{
AndroidBitmapInfo infocolor;
void* pixelscolor;
AndroidBitmapInfo infogray;
void* pixelsgray;
int ret;
int y;
int x;
LOGI("convertToGray");
if ((ret = AndroidBitmap_getInfo(env, bitmapcolor, &infocolor)) < 0) {
LOGE("AndroidBitmap_getInfo() failed ! error=%d", ret);
return;
}
if ((ret = AndroidBitmap_getInfo(env, bitmapgray, &infogray)) < 0) {
LOGE("AndroidBitmap_getInfo() failed ! error=%d", ret);
return;
}
LOGI("color image :: width is %d; height is %d; stride is %d; format is %d;flags is %d",infocolor.width,infocolor.height,infocolor.stride,infocolor.format,infocolor.flags);
if (infocolor.format != ANDROID_BITMAP_FORMAT_RGBA_8888) {
LOGE("Bitmap format is not RGBA_8888 !");
return;
}
LOGI("gray image :: width is %d; height is %d; stride is %d; format is %d;flags is %d",infogray.width,infogray.height,infogray.stride,infogray.format,infogray.flags);
if (infogray.format != ANDROID_BITMAP_FORMAT_A_8) {
LOGE("Bitmap format is not A_8 !");
return;
}
if ((ret = AndroidBitmap_lockPixels(env, bitmapcolor, &pixelscolor)) < 0) {
LOGE("AndroidBitmap_lockPixels() failed ! error=%d", ret);
}
if ((ret = AndroidBitmap_lockPixels(env, bitmapgray, &pixelsgray)) < 0) {
LOGE("AndroidBitmap_lockPixels() failed ! error=%d", ret);
}
// modify pixels with image processing algorithm
for (y=0;y<infocolor.height;y++) {
argb * line = (argb *) pixelscolor;
uint8_t * grayline = (uint8_t *) pixelsgray;
for (x=0;x<infocolor.width;x++) {
grayline[x] = 0.3 * line[x].red + 0.59 * line[x].green + 0.11*line[x].blue;
}
pixelscolor = (char *)pixelscolor + infocolor.stride;
pixelsgray = (char *) pixelsgray + infogray.stride;
}
LOGI("unlocking pixels");
AndroidBitmap_unlockPixels(env, bitmapcolor);
AndroidBitmap_unlockPixels(env, bitmapgray);
}
My Java functions:
// load bitmap from resources
BitmapFactory.Options options = new BitmapFactory.Options();
// Make sure it is 24 bit color as our image processing algorithm expects this format
options.inPreferredConfig = Config.ARGB_8888;
bitmapOrig = BitmapFactory.decodeResource(this.getResources(), R.drawable.sampleimage,options);
if (bitmapOrig != null)
ivDisplay.setImageBitmap(bitmapOrig);
-
bitmapWip = Bitmap.createBitmap(bitmapOrig.getWidth(),bitmapOrig.getHeight(),Config.ALPHA_8);
convertToGray(bitmapOrig,bitmapWip);
ivDisplay.setImageBitmap(bitmapWip);
Thanks, N
P.S My last question of the same subject got deleted, which is annoying as I can't find any answers to this anywhere.
Images are loaded with the ARGB_8888 config by default, according to the documentation, so my guess is that it recognizes the RGB_565 format of your bitmap and changes the config for that. I don't see why this should be a problem if the original image is of RGB_565 format and has no transparency.
Here's the documentation - read the last bit:
If this is non-null, the decoder will try to decode into this internal configuration. If it is null, or the request cannot be met, the decoder will try to pick the best matching config based on the system's screen depth, and characteristics of the original image such as if it has per-pixel alpha (requiring a config that also does). Image are loaded with the ARGB_8888 config by default.
http://developer.android.com/reference/android/graphics/BitmapFactory.Options.html#inPreferredConfig
This is old, but so far not satisfactory answered:
Just ran into the same problem the other day.
So far I couldn't solve it and I'm considering writing a converter. Since I'm using OpenCV and they don't support the 565 format.
Saving the image and loading it again with different configuration works, but unfortunately for a real time camera application this is not feasible.
Have a look at this code:
How does one convert 16-bit RGB565 to 24-bit RGB888?
I know the Android platform is a huge mess, over complicated and over-engineered, but seriously to get the size of a bitmap, is it really necessary to do all those conversions?
Bitmap bitmap = your bitmap object
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream);
byte[] imageInByte = stream.toByteArray();
long length = imageInByte.length;
According to Google Documentation Bitmap has a method getByteCount() to do this, however it is not present in SDK2.2, haven't tried other's but there is no mention of it being deprecated or that API support is any different from API 1... So where is this mysterious method hiding? It would really nice to be albe to simple do
bitmap.getByteCount()
I just wrote this method.
AndroidVersion.java is a class I created to easily get me the version code from the phone.
http://code.google.com/p/android-beryl/source/browse/beryl/src/org/beryl/app/AndroidVersion.java
public static long getSizeInBytes(Bitmap bitmap) {
if(AndroidVersion.isHoneycombMr2OrHigher()) {
return bitmap.getByteCount();
} else {
return bitmap.getRowBytes() * bitmap.getHeight();
}
}
If you filter by API Level 8 (= SDK 2.2), you'll see that Bitmap#getByteCount() is greyed out, meaning that method is not present in that API level.
getByteCount() was added in API Level 12.
The answers here are a bit outdated. Reason (in the docs) :
getByteCount : As of KITKAT, the result of this method can no longer
be used to determine memory usage of a bitmap. See
getAllocationByteCount().
So, the current answer should be :
int result=BitmapCompat.getAllocationByteCount(bitmap)
or, if you insist on writing it yourself:
public static int getBitmapByteCount(Bitmap bitmap) {
if (VERSION.SDK_INT < VERSION_CODES.HONEYCOMB_MR1)
return bitmap.getRowBytes() * bitmap.getHeight();
if (VERSION.SDK_INT < VERSION_CODES.KITKAT)
return bitmap.getByteCount();
return bitmap.getAllocationByteCount();
}
Before API 12 you can calculate the byte size of an Bitmap using getHeight() * getWidth() * 4 if you are using ARGB_8888 because every pixel is stored in 4bytes. I think this is the default format.
As mentioned in other answers, it is only available on API 12 or higher. This is a simple compatibility version of the method.
public static int getByteCount(Bitmap bitmap) {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.HONEYCOMB_MR1) {
return bitmap.getRowBytes() * bitmap.getHeight();
} else {
return bitmap.getByteCount();
}
}
I tried all of the above methods and they were close, but not quite right (for my situation at least).
I was using bitmap.getByteCount(); inside of the sizeOf() method when creating a new LruCache:
mMemoryCache = new LruCache<String, Bitmap>(cacheSize) {
#Override
protected int sizeOf(String key, Bitmap bitmap) {
return bitmap.getByteCount();
}
};
I then tried the suggested:
return bitmap.getRowBytes() * bitmap.getHeight();
This was great, but I noticed that the returned values were different and when I used the suggestion above, it would not even make a cache on my device. I tested the return values on a Nexus One running api 3.2 and a Galaxy Nexus running 4.2:
bitmap.getByteCount(); returned-> 15
bitmap.getRowBytes() * bitmap.getHeight(); returned-> 15400
So to solve my issue, I simply did this:
return (bitmap.getRowBytes() * bitmap.getHeight()) / 1000;
instead of:
return bitmap.getByteCount();
May not be the same situation you were in, but this worked for me.
As you can see in the source code, getByteCount is simply this:
public final int getByteCount() {
// int result permits bitmaps up to 46,340 x 46,340
return getRowBytes() * getHeight();
}
Here is the source code for 5.0