I am developing an application using JNI and a third party engine (Unreal Engine 4) in charge of managing the graphics pipeline/rendering.
The third party engine is written in C++, thus the need of using JNI to bridge it with Android.
The app requires to save a screenshot on the device of what is being displayed on the screen (in other words a dump of the framebuffer).
The third party engine exposes an API that calls a custom handler, passing in the width, height and color data of the screen.
colordata is a custom container of uint8 representing RGBA components.
I successfully managed to convert the colorData to a jbyteArray and pass it as an argument to a function on the JAVA side.
On the java side things are simpler: I create a bitmap from the byteArray, flip it and save it as a jpg/png via a custom AsyncTask.
The problem:
The code works marvellously o Samsung Galaxy S4/Note3 (Both Android 5.0), whereas on a Nexus 10 Android version 5.1.1 the png that gets saved is blank.
I am afraid that the problem with this lies on a depper level than the ones I have access to, i.e. graphics card/drivers/OS version, but I am not an expert in that field, so I would like to know if someone has already experienced a similar issue or could shed some light on what is causing it.
This is the code used to bridge the engine with Java (I started c++ with this project so maybe there are ownership/memory issues in this snippet. You are more than welcome to correct me in case :))
void AndroidInterface::SaveBitmap(const TArray<FColor>& colorData, int32 width, int32 height) {
JNIEnv* env = FAndroidApplication::GetJavaEnv(true);
TArray<FColor> bitmap = colorData;
TArray<uint8> compressedBitmap;
FImageUtils::CompressImageArray(width, height, bitmap, compressedBitmap);
size_t len = width*height*compressedBitmap.GetTypeSize();
LOGD("===========Width: %i, height: %i - Len of bitmap element: %i==========", width, height, len);
jbyteArray bitmapData = env->NewByteArray(len);
LOGD("===========Called new byte array==========");
env->SetByteArrayRegion(bitmapData, 0, len, (const jbyte*)compressedBitmap.GetData() );
LOGD("===========Populated byte array==========");
check (bitmapData != NULL && "Couldn't create byte array");
jclass gameActivityClass = FAndroidApplication::FindJavaClass("com/epicgames/ue4/GameActivity");
check (gameActivityClass != nullptr && "GameActivityClassNotFound");
//get the method signature to take a game screenshot
jmethodID saveScreenshot = env->GetMethodID(gameActivityClass, "saveScreenshot", "([BII)V");
env->CallVoidMethod(AndroidInterface::sGameActivity, saveScreenshot, bitmapData, width, height);
env->DeleteLocalRef(bitmapData);
}
This is the java code in charge of converting from byte[] to Bitmap:
public void saveScreenshot(final byte[] colors, int width, int height) {
android.util.Log.d("GameActivity", "======saveScreenshot called. Width: " + width + " height: " + height + "=======");
android.util.Log.d("GameActivity", "Color content---->\n " + Arrays.toString(colors));
final BitmapFactory.Options opts = new BitmapFactory.Options();
opts.inPreferredConfig = Bitmap.Config.ARGB_8888;
final Bitmap bitmap = BitmapFactory.decodeByteArray(colors, 0, colors.length, opts);
final FlipBitmap flipBitmapTask = new FlipBitmap();
flipBitmapTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, bitmap);
}
FlipBitmap is the AsyncTask in charge of saving the bitmap to a file:
private class FlipBitmap extends AsyncTask<Bitmap, Void, File> {
#Override
protected File doInBackground(Bitmap... params) {
final Bitmap src = params[0];
final File file = new File(MainActivity.SCREENSHOT_FOLDER + "screenshot" + System.currentTimeMillis() + ".png");
final Matrix matrix = new Matrix();
matrix.setScale(1, -1);
final Bitmap dst = Bitmap.createBitmap(src, 0, 0, src.getWidth(), src.getHeight(), matrix, false);
try {
final FileOutputStream out = new FileOutputStream(file);
dst.compress(Bitmap.CompressFormat.PNG, 90, out);
out.flush();
out.close();
} catch (Exception e) {
e.printStackTrace();
}
return file;
}
#Override
protected void onPostExecute(File file) {
android.util.Log.d("GameActivity", "FlipBitmap onPostExecute");
if (file.exists()) {
final Intent i = new Intent(Intent.ACTION_SENDTO);
i.setData(Uri.parse("mailto:" + Globals.Network.MAIL_TO));
i.putExtra(Intent.EXTRA_SUBJECT, Globals.Network.MAIL_SUBJECT);
i.putExtra(Intent.EXTRA_TEXT, mBodyEmail);
i.putExtra(Intent.EXTRA_STREAM, Uri.parse("file://" + file.getAbsolutePath()));
startActivity(Intent.createChooser(i, "Invia via email"));
}
}
}
Thanks in advance!
Related
So my issue is that I get for a video call the frames in my c code as a byte array of I420. Which I then convert to NV21 and send the byte array to create the bitmap. But because I need to create a YUV Image from the byte array, and then a bitmap from that, I have a conversion overhead and that is causing delays and loss in quality.
I am wondering if there is another way to do this. Somehow so that I can create the bitmap directly in the c code, and maybe even add it to the bitmap, or a surface view from the c code? Or just simply send the bitmap to my function so I can set it there, without needing to create the bitmap in Android.
This is what I do with the byte array in the c code:
if(size == 0)
return;
jboolean isAttached;
JNIEnv *env;
jint jParticipant;
jint jWidth;
jint jHeight;
jbyteArray jRawImageBytes;
env = getJniEnv(&isAttached);
if (env == NULL)
goto FAIL0;
//LOGE(".... **** ....TRYING TO FIND CALLBACK");
LOGI("FrameReceived will reach here 1");
char *modifiedRawImageBytes = malloc(size);
memcpy(modifiedRawImageBytes, rawImageBytes, size);
jint sizeWH = width * height;
jint quarter = sizeWH/4;
jint v0 = sizeWH + quarter;
for (int u = sizeWH, v = v0, o = sizeWH; u < v0; u++, v++, o += 2) {
modifiedRawImageBytes[o] = rawImageBytes[v]; // For NV21, V first
modifiedRawImageBytes[o + 1] = rawImageBytes[u]; // For NV21, U second
}
if(remote)
{
if(frameReceivedRemoteMethod == NULL)
frameReceivedRemoteMethod = getApplicationJniMethodId(env, applicationJniObj, "vidyoConferenceFrameReceivedRemoteCallback", "(III[B)V");
if (frameReceivedRemoteMethod == NULL) {
//LOGE(".... **** ....CALLBACK NOT FOUND");
goto FAIL1;
}
}
This is what I do in the Android java code:
remoteResolution = width + "x" + height;
remoteBAOS = new ByteArrayOutputStream();
remoteYUV = new YuvImage(rawImageBytes, ImageFormat.NV21, width, height, null);
remoteYUV.compressToJpeg(new Rect(0, 0, width, height), 100, remoteBAOS);
remoteBA = remoteBAOS.toByteArray();
remoteBitmap = BitmapFactory.decodeByteArray(remoteBA, 0, remoteBA.length);
new Handler(Looper.getMainLooper()).post(new Runnable() {
#Override
public void run() {
remoteView.setImageBitmap(remoteBitmap);
}
});
This is how the sample app of the SDK I am using had the sample. but I feel that this is not at all best practice, and there has to be a way to get the Bitmap quicker from the byte array, and preferably in the c code. Any ideas on how to improve this?
EDIT:
I modified my Java code. I know use this library: https://github.com/silvaren/easyrs
so my code will be:
remoteBitmap = Nv21Image.nv21ToBitmap(rs, rawImageBytes, width, height);
new Handler(Looper.getMainLooper()).post(new Runnable() {
#Override
public void run() {
remoteView.setImageBitmap(remoteBitmap);
}
});
Where nv21ToBitmap does this:
public static Bitmap yuvToRgb(RenderScript rs, Nv21Image nv21Image) {
long startTime = System.currentTimeMillis();
Type.Builder yuvTypeBuilder = new Type.Builder(rs, Element.U8(rs))
.setX(nv21Image.nv21ByteArray.length);
Type yuvType = yuvTypeBuilder.create();
Allocation yuvAllocation = Allocation.createTyped(rs, yuvType, Allocation.USAGE_SCRIPT);
yuvAllocation.copyFrom(nv21Image.nv21ByteArray);
Type.Builder rgbTypeBuilder = new Type.Builder(rs, Element.RGBA_8888(rs));
rgbTypeBuilder.setX(nv21Image.width);
rgbTypeBuilder.setY(nv21Image.height);
Allocation rgbAllocation = Allocation.createTyped(rs, rgbTypeBuilder.create());
ScriptIntrinsicYuvToRGB yuvToRgbScript = ScriptIntrinsicYuvToRGB.create(rs, Element.RGBA_8888(rs));
yuvToRgbScript.setInput(yuvAllocation);
yuvToRgbScript.forEach(rgbAllocation);
Bitmap bitmap = Bitmap.createBitmap(nv21Image.width, nv21Image.height, Bitmap.Config.ARGB_8888);
rgbAllocation.copyTo(bitmap);
Log.d("NV21", "Conversion to Bitmap: " + (System.currentTimeMillis() - startTime) + "ms");
return bitmap;
}
This is faster. but still I feel there still is some delay. Now that I get my bitmap from renderscript instead of using a YUV Image. Is it possible to set it to my imageView somehow faster? or set it on a surfaceView somehow?
What My code does . is take a snapshot of the map convert it to gray (opencv) and then make it to byte array.
Now what I dont know how to start doing is making this Bytearray to a 2D Array,
here is a block of the code.
Date now = new Date();
android.text.format.DateFormat.format("yyyy-MM-dd_hh:mm:ss",now);
try {
StrictMode.ThreadPolicy old = StrictMode.getThreadPolicy();
StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder(old)
.permitDiskWrites()
.build());
String mPath = Environment.getExternalStorageDirectory().toString() + "/" + now + ".jpg";
File imageFile = new File(mPath);
FileOutputStream out = new FileOutputStream(imageFile);
bitmap.compress(Bitmap.CompressFormat.PNG,90,out);
Log.d("Image:","Saved Snashot. Starting covertion");
//show snapshot in imageview
ImageView imgview = (ImageView) findViewById(R.id.imageView);
Bitmap smyBitmap = BitmapFactory.decodeFile(mPath);
Bitmap myBitmap = BitmapFactory.decodeFile(mPath);
imgview.setImageBitmap(smyBitmap);
Mat mat = new Mat(myBitmap.getHeight(),myBitmap.getWidth(),CvType.CV_8UC3);
Mat mat1 = new Mat(myBitmap.getHeight(),myBitmap.getWidth(),CvType.CV_8UC1);
Imgproc.cvtColor(mat,mat1,Imgproc.COLOR_BGR2GRAY);
ImageView imgview2 = (ImageView) findViewById(R.id.imageView2);
Mat tmp = new Mat (myBitmap.getWidth(), myBitmap.getHeight(), CvType.CV_8UC1);
Utils.bitmapToMat(myBitmap, tmp);
Imgproc.cvtColor(tmp, tmp, Imgproc.COLOR_RGB2GRAY);
Utils.matToBitmap(tmp, myBitmap);
// Utils.matToBitmap(mat1,img);
String mPathgray = Environment.getExternalStorageDirectory().toString() + "/" + now + "gray.jpg";
File imageFilegray = new File(mPathgray);
FileOutputStream gout = new FileOutputStream(imageFilegray);
bitmap.compress(Bitmap.CompressFormat.PNG,90,gout);
byte[] byteArray = bttobyte(myBitmap);
Log.d("location"," " + mPathgray);
imgview2.setImageBitmap(myBitmap);
Log.d("Activity", "Byte array: "+ Arrays.toString(byteArray));
}
catch (Exception e) {
e.printStackTrace();
}
}
};
mMap.snapshot(callback);
Log.d("test","test2");
}
});
}
public byte[] bttobyte(Bitmap bitmap) {
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG, 70, stream);
return stream.toByteArray();
}
The problem you are trying to solve is actually extracting image data from JPEG encoding in the byte array. It is not as simple as being stored pixel by pixel in a grid of width and height equal to your image size, as you seem to be implying. That is a consequence of using this
bitmap.compress(Bitmap.CompressFormat.JPEG, 70, stream);
For example that byte data actually might encode JFIF format:
0xffd8 - SOI - exactly 1 - start of image
e.g. 0xffe0 - zero or more - e.g. APP0 for JFIF - [some sort of header, either JFIF or EXIF].
0xffdb - DQT - one or more - define quantisation tables. These are the main source of quality in the image.
0xffcn - SOFn - exactly one - start of frame. SOF0 indicates a baseline DCT JPEG
0xffc4 - DHT - one or more - define Huffman tables. These are used in the final lossless encoding steps.
0xffda - SOS - exactly one (for baseline, more than one intermixed with more DHTs if progressive) - start of stream. This is where the actual data starts.
0xffd9 - EOI - exactly one - end of image.
Essentially once you have transformed your bitmap, you need a JPEG decoder to parse this data.
I think what you want is to be working with the original bitmap. For example there are APIs to extract pixel data. That is what you need if I understand what it is you want to do correctly.
Bitmap.getPixels(int[] pixels,
int offset,
int stride,
int x,
int y,
int width,
int height)
The array pixels[] is filled with data. You can then parse the array if you want to store it in a w by h 2D array by iterating copying the data. Something like:
int offset = 0;
int pixels2d[w][h]= new int[w][h];
for (int[] row : pixels2d) {
System.arraycopy(pixels, offset, row, 0, row.length);
offset += row.length;
}
You just create a new array with 2 dimensions
byte[][] picture = new byte[myBitmap.getWidth()][,myBitmap.getHeight()]
which you can access via
byte myByte = picture[x][y]
after this you iterate your original bytarray by line followed by row
I am trying to restore the image from Native memory (using NDK,C/C++) but that returns me an Black Image.
What i am doing ::
1)get the image from Drawable
2)apply the rotation to the image
3)After rotation apply the grayscale effect to the image
4)At the end i am trying to save the grayscale image in SD Card
For all the above steps, i am referring this awesome lib,which have the native method to store and restore the images.
Please note image is being stored in the SD card but when i am trying to see the image,its totally black with no display at all.
My Java Implementation ::
public boolean onOptionsItemSelected(MenuItem item)
{
switch (item.getItemId())
{
case R.id.item_rotate_90:
options.inPreferredConfig = Config.ARGB_8888;
bitmapOrig = BitmapFactory.decodeResource(this.getResources(), R.drawable.sample_cam,options);
storeBitmap(bitmapOrig);
bitmapOrig.recycle();
rotateBitmap(90,_handler);
tempBmp=getBitmapAndFree();
bitmapWip = Bitmap.createBitmap(bitmapOrig.getWidth(),bitmapOrig.getHeight(),Config.ALPHA_8);
jniConvertToGray(tempBmp,bitmapWip);
if(bitmapWip!=null)
{
try
{
Bitmap b = Bitmap.createBitmap(bitmapWip.getWidth(),bitmapWip.getHeight(),Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(b);
Paint paint = new Paint();
ColorMatrix cm = new ColorMatrix();
ColorMatrixColorFilter f = new ColorMatrixColorFilter(cm);
paint.setColorFilter(f);
c.drawBitmap(bitmapWip, 0, 0, paint);
storeBitmap(b);
SaveGrayScaledImage(b);
b.recycle();
tempBmp.recycle();
} catch (IOException e) {
e.printStackTrace();
}
ivDisplay.setImageBitmap(bitmapWip);
}
break;
}
}
I have not make any changes in native method(means using the same method as this lib have for storing and restoring the image).
Saving image to SD Card ::
private void SaveGrayScaledImage(Bitmap finalBitmap)throws IOException
{
String imageFileName = "Temp" + "_gray";
File albumF = new File("/mnt/sdcard/","gray_img");
if(!albumF.exists())
{
albumF.mkdirs();
}
// File imageF = File.createTempFile(imageFileName, JPEG_FILE_SUFFIX,
// albumF);
File imageF = new File(albumF,imageFileName + ".jpeg");
if (imageF.exists()) {
imageF.delete();
imageF.createNewFile();
}
try {
FileOutputStream out = new FileOutputStream(imageF);
finalBitmap.compress(Bitmap.CompressFormat.JPEG, 100, out);
out.flush();
out.close();
} catch (Exception e) {
e.printStackTrace();
imageF = null;
}
}
While googling, i found that(may be i am wrong) image which returns for Native Memory have the ALPHA_8 bitmap config,so i convert the config ALPHA_8 t0 ARGB_8888,but the result is same.
Conversion of bitmap from ALPHA_8 to ARGB_8888 ::
Bitmap b = Bitmap.createBitmap(bitmapWip.getWidth(),bitmapWip.getHeight(),Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(b);
Paint paint = new Paint();
ColorMatrix cm = new ColorMatrix();
ColorMatrixColorFilter f = new ColorMatrixColorFilter(cm);
paint.setColorFilter(f);
c.drawBitmap(bitmapWip, 0, 0, paint);
StoreBimap funcation ::
public void storeBitmap(final Bitmap bitmap)
{
if(_handler!=null)
freeBitmap();
_handler=jniStoreBitmapData(bitmap);
}
I have no clue about where i was wrong. i have checked the lib methods and implmentation again and again to find the issue.
I have spent my many hours on this small issue and it really frustrating me.
Let me know please if you need anything else from my side.
Please help me to resolve this issue.
Many Thanks in Advance....
EDIT ::
bitmapHolder=new JniBitmapHolder();
final Options options=new Options();
BitmapFactory.decodeFile(picPath, options);
options.inJustDecodeBounds=true;
options.inPreferredConfig=Config.ARGB_8888;
prepareForDownsampling(options,192,256);
System.gc();
bmpGrayscale=BitmapFactory.decodeFile(picPath,options);
int width = bmpGrayscale.getWidth();
int height = bmpGrayscale.getHeight();
bitmapHolder.storeBitmap(bmpGrayscale);
bmpGrayscale.recycle();
Bitmap thumbnail = null;
int rotationInDegrees = 0;
if (picPath != null) {
Uri uri = Uri.parse(picPath);
ExifInterface exif = null;
try {
exif = new ExifInterface(uri.getPath());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
int rotation = exif.getAttributeInt(
ExifInterface.TAG_ORIENTATION,
ExifInterface.ORIENTATION_NORMAL);
rotationInDegrees = exifToDegrees(rotation);
}
rotationInDegrees = 90;
ByteBuffer _handler =null;
switch(rotationInDegrees)
{
case 90:
bitmapHolder.rotateBitmapCw90();
break;
case 180:
bitmapHolder.rotateBitmap180();
break;
}
Bitmap bitmapWip = Bitmap.createBitmap(width,height,Config.ALPHA_8);
bitmapHolder.bitmapGrayScale(bitmapWip);
if(bitmapWip!=null){
File CurrentFile = saveGrayScaledIamge(bitmapWip,
takePhotoFile);
}
I have followed your suggestion/steps but the result is same,getting black image with no display.
ok I've found multiple problems and tips for improvements:
the first createBitmap is run with width*height on a bitmap that got rotated instead of height*width. this should be as:
rotateBitmap(90,_handler);
tempBmp=getBitmapAndFree();
bitmapWip=Bitmap.createBitmap(bitmapOrig.getHeight(),bitmapOrig.getWidth(),Config.ALPHA_8);
when saving file you don't get the correct path (you use a hardcoded path, and Lint warns about it).
jniConvertToGray doesn't really need to go over arrays and can just use a pointer, as it just runs on a single pixel. you store the bitmap into JNI twice instead of once (just do: store, rotate, grayscale, restore&free).
you don't use the new bitmap after you have finished working on it, so if I call rotation multiple times, it doesn't seem to do anything.
you already have bitmapWip rotated and grayscaled. why do you need to make a new bitmap that has its content in it, do a grayscale on it, and then save it ?
functions should be named with lowercase letter in the beginning of their names.
and finally , the most important thing: you use ALPHA_8 for the image that you show and need to save to file. this configuration has no color. it's a mask. In order to see the problem, you should set a background color to the imageView :
ivDisplay.setBackgroundColor(0xFFff0000);
before choosing the rotation, you see nothing red. after choosing it, everything you think is white, has actually become red. that's because it's transparent...
If in any phase of your development you've succeeded saving the image to a file and thought it's a black image (yet the size is not 0) , try to edit it and put a background behind it. Maybe you got lucky and just got transparent pixels...
Adding the fact that you save the file to a jpg format, which doesn't support transparency, might also contribute to unexpected behaviors.
in order to solve this, you should use the same technique i've used - use a single bitmap all the time. no need to create so many. only one should exist on the java world, and it should support having colors.
I am trying to fetch an image from a URL into a Bitmap and then using the raw data from the Bitmap am trying to create a CCSprite. The issue here is that the image is corrupted when I display the sprite. I created a standalone android only application(no cocos2dx) and used the same code to fetch and display the Bitmap and its displayed correctly. Any reason why the image is not being properly rendered in cocos2dx?
My code to fetch the image from the URL is:
String urlString = "http://www.mathewingram.com/work/wp-content/themes/thesis/rotator/335f69c5de_small.jpg";//http://graph.facebook.com/"+user.getId()+"/picture?type=large";
Bitmap pic = null;
pic = BitmapFactory.decodeStream((InputStream) new URL(urlString).getContent());
int[] pixels = new int[pic.getWidth() * pic.getHeight()];
pic.getPixels(pixels, 0, pic.getWidth(), 0, 0,pic.getWidth(),pic.getHeight());
int len = pic.getWidth()* pic.getHeight();
nativeFbUserName(pixels,len,pic.getWidth(), pic.getHeight());
The function "nativeFbUserName" is a call to a native c++ function which is :
void Java_com_WBS_Test0001_Test0001_nativeFbUserName(JNIEnv *env, jobject thiz,jintArray name, jint len, jint width, jint height) {
jint *jArr = env->GetIntArrayElements(name,NULL);
int username[len];
for (int i=0; i<len; i++){
username[i] = (int)jArr[i];
}
HelloWorld::getShared()->picLen = (int)len;
HelloWorld::getShared()->picHeight = (int)height;
HelloWorld::getShared()->picWidth = (int)width;
HelloWorld::getShared()->saveArray(username);
HelloWorld::getShared()->schedule(SEL_SCHEDULE(&HelloWorld::addSprite),0.1);
}
void HelloWorld::saveArray(int *arrayToSave)
{
arr = new int[picLen];
for(int i = 0; i < picLen; i++){
arr[i] = arrayToSave[i];
}
}
void HelloWorld::addSprite(float time)
{
this->unschedule(SEL_SCHEDULE(&HelloWorld::addSprite));
CCTexture2D *tex = new CCTexture2D();
bool val = tex->initWithData(arr,(cocos2d::CCTexture2DPixelFormat)0,picWidth,picHeight, CCSizeMake(picWidth,picHeight));
CCLog("flag is %d",val);
CCSprite *spriteToAdd = CCSprite::createWithTexture(tex);
spriteToAdd->setPosition(ccp(500, 300));
this->addChild(spriteToAdd);
}
Edit:
So I found this link Access to raw data in ARGB_8888 Android Bitmap that states that it might be a bug. Has anyone found a solution to this?
EDIT
So I just noticed a corruption of images on the lower right corner of the image.I am not sure why this is happening and how to fix it. Any ideas?
EDIT END
Answering my own question, I obtained a byte array from the bitmap using:
byte[] data = null;
ByteArrayOutputStream baos = new ByteArrayOutputStream();
pic.compress(Bitmap.CompressFormat.JPEG, 100, baos);
data = baos.toByteArray();
And then passed this byte array to the native code.
I need to convert bytes of an CYMK image to bytes for RGB image.
I think it's possible to skip the bytes of the header and convert others bytes in RGB and then change the header bytes for RGB format.
Which are the header bytes to change for RGB?
Which is the formula for the bit color conversion without ICC profile?
Can anybody help me to complete this code?
//Decode with inSampleSize
Bitmap Resultbitmap;
string path = "imageFileCmyk.jpg";
int scale=4;
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inPurgeable = true;
o2.inSampleSize=scale;
o2.inDither = false;
Resultbitmap = BitmapFactory.decodeStream(new FileInputStream(path), null, o2);
if (Resultbitmap==null) // Warning!! unsupported color conversion request
{
File tmpfile = new File(path);
FileInputStream is = new FileInputStream(tmpfile.getPath());
byte[] cmykBytes= new byte[(int)tmpfile.length()];
byte[] rgbBytes= new byte[(int)tmpfile.length()];
is.read(cmykBytes);
for (int i = 0; cmykBytes.length>i; ++i)
{
if (i>11) // skip header's bytes, is it correct ??
{
rgbBytes[i] = cmykBytes[i]?? // How ??
}
}
// new header bytes for RGB format
rgbBytes[??]= ?? // How ??
Resultbitmap = BitmapFactory.decodeByteArray(rgbBytes, 0, rgbBytes.length, o2);
}
return Resultbitmap;
Thanks,
Alberto
I made it! I found a nice tool for correct handling *.jpg files on Android platform with uncommon colorspaces like CMYK, YCCK and so on.
Use https://github.com/puelocesar/android-lib-magick, it's free and easy to configure android library.
Here is a snippet for converting CMYK images to RGB colorspace:
ImageInfo info = new ImageInfo(Environment.getExternalStorageDirectory().getAbsolutePath() + "/cmyk.jpg");
MagickImage imageCMYK = new MagickImage(info);
Log.d(TAG, "ColorSpace BEFORE => " + imageCMYK.getColorspace());
boolean status = imageCMYK.transformRgbImage(ColorspaceType.CMYKColorspace);
Log.d(TAG, "ColorSpace AFTER => " + imageCMYK.getColorspace() + ", success = " + status);
imageCMYK.setFileName(Environment.getExternalStorageDirectory().getAbsolutePath() + "/cmyk_new.jpg");
imageCMYK.writeImage(info);
Bitmap bitmap = BitmapFactory.decodeFile(Environment.getExternalStorageDirectory().getAbsolutePath()
+ "/Docs/cmyk_new.jpg");
if (bitmap == null) {
//if decoding fails, create empty image
bitmap = Bitmap.createBitmap(imageCMYK.getWidth(), imageCMYK.getHeight(), Config.ARGB_8888);
}
ImageView imageView1 = (ImageView) findViewById(R.id.imageView1);
imageView1.setImageBitmap(bitmap);
Just importing android-lib-magick the code to transform its colorspace is quite simple:
ImageInfo info = new ImageInfo(path); // path where the CMYK image is your device
MagickImage imageCMYK = new MagickImage(info);
imageCMYK.transformRgbImage(ColorspaceType.CMYKColorspace);
Bitmap bitmap = MagickBitmap.ToBitmap(imageCMYK);
Kord, even it is not needed to save again the transformed image, you can just create a bitmap with it. If the image is not in your device or on your SD card, you will need to download it first.
I have implemented two simple methods using android-lib-magick called "getCMYKImageFromPath" and "getCMYKImageFromURL". You can see the code here:
https://github.com/Mariovc/GetCMYKImage