I have Xamarin Android project and I would like to recognize QR code from camera and save picture to storage at the same time. I used Android.Hardware.Camera.IPreviewCallback to get image from camera. Saving image works as expected but recognition of QR code fails. Here is my code:
void Android.Hardware.Camera.IPreviewCallback.OnPreviewFrame(byte[] data, Android.Hardware.Camera camera)
{
byte[] jpegData = ConvertYuvToJpeg(data);
Bitmap bitmap = BytesToBitmap(jpegData);
SaveBitmapImage(bitmap); // This works great
var width = (int)_textureView.Width;
var height = (int)_textureView.Height;
// How to get LuminanceSource??
//LuminanceSource source = new RGBLuminanceSource(rgbValues, bm.Width, bm.Height, RGBLuminanceSource.BitmapFormat.ARGB32);
//LuminanceSource source = new RGBLuminanceSource( jpegData, width, height);
LuminanceSource source = new PlanarYUVLuminanceSource(data, width, height,
0, 0, width, height, false);
BinaryBitmap binaryBitmap = new BinaryBitmap(new HybridBinarizer(source));
QRCodeReader reader = new QRCodeReader();
var result = reader.decode(binaryBitmap);
}
Call to
var result = reader.decode(binaryBitmap);
always returns null.
Edit:
It seems that problem is with camera. It is not focusing on QR code, image is blurry and ZXing library is unable to decode it. How can I make camera focus?
Problem is with camera focus. Focus mode must be set. Here is a code:
var parameters = _camera.GetParameters();
parameters.FocusMode = GetOptimalFocusMode(parameters);
_camera.SetParameters(parameters);
private String GetOptimalFocusMode(Android.Hardware.Camera.Parameters parameters)
{
String result;
IList<String> focusModes = parameters.SupportedFocusModes;
if (focusModes.Contains(Android.Hardware.Camera.Parameters.FocusModeContinuousVideo))
{
result = Android.Hardware.Camera.Parameters.FocusModeContinuousVideo;
}
else if (focusModes.Contains(Android.Hardware.Camera.Parameters.FocusModeAuto))
{
result = Android.Hardware.Camera.Parameters.FocusModeAuto;
}
else
{
result = parameters.SupportedFocusModes.First();
}
return result;
}
Related
I am using SharpDX to basically render browser (chromium) output buffer on directX process.
Process is relatively simple, I intercept CEF buffer (by overriding OnPaint method) and write that to a texture2D.
Code is relatively simple:
Texture creation:
public void BuildTextureWrap() {
var oldTexture = texture;
texture = new D3D11.Texture2D(DxHandler.Device, new D3D11.Texture2DDescription() {
Width = overlay.Size.Width,
Height = overlay.Size.Height,
MipLevels = 1,
ArraySize = 1,
Format = DXGI.Format.B8G8R8A8_UNorm,
SampleDescription = new DXGI.SampleDescription(1, 0),
Usage = D3D11.ResourceUsage.Default,
BindFlags = D3D11.BindFlags.ShaderResource,
CpuAccessFlags = D3D11.CpuAccessFlags.None,
OptionFlags = D3D11.ResourceOptionFlags.None,
});
var view = new D3D11.ShaderResourceView(
DxHandler.Device,
texture,
new D3D11.ShaderResourceViewDescription {
Format = texture.Description.Format,
Dimension = D3D.ShaderResourceViewDimension.Texture2D,
Texture2D = { MipLevels = texture.Description.MipLevels },
}
);
textureWrap = new D3DTextureWrap(view, texture.Description.Width, texture.Description.Height);
if (oldTexture != null) {
obsoleteTextures.Add(oldTexture);
}
}
That piece of code is executed at start and when resize is happening.
Now when CEF OnDraw I basically copy their buffer to texture:
var destinationRegion = new D3D11.ResourceRegion {
Top = Math.Min(r.dirtyRect.y, texDesc.Height),
Bottom = Math.Min(r.dirtyRect.y + r.dirtyRect.height, texDesc.Height),
Left = Math.Min(r.dirtyRect.x, texDesc.Width),
Right = Math.Min(r.dirtyRect.x + r.dirtyRect.width, texDesc.Width),
Front = 0,
Back = 1,
};
// Draw to the target
var context = targetTexture.Device.ImmediateContext;
context.UpdateSubresource(targetTexture, 0, destinationRegion, sourceRegionPtr, rowPitch, depthPitch);
There are some more code out there but basically this is only relevant piece. Whole thing works until OnDraw happens frequently.
Apparently if I force CEF to Paint frequently, whole host process dies.
This is happening at UpdateSubresource.
So my question is, is there another, safer way to do this? (Update texture frequently)
Solution to this problem was relatively simple yet not so obvious at the beginning.
I simply moved the code responsible for updating texture inside render loop and just keep internal buffer pointer cached.
In my Xamarin Forms app, I have an image under androidProject/Resources/drawable/myImage.png. To load these from Xamarin, you can simply do
Image myImage = new Image() { Source = ImageSource.FromFile("myImage.png") };
However, there is no way to draw an Image using NGraphics. Instead, NGraphics DrawImage(IImage) requires an IImage. As far as I can tell, there's no way to turn a Xamarin.Forms.Image into an NGraphics.IImage. In fact, the only way I could find to load IImage is
IImage myImage = Platform.LoadImage("myImage.png");
However, this doesn't work because under the hood this uses BitmapFactory.decodeFile(), which requires the absolute file path. And I couldn't find any way to get the absolute file path of a resource (if it even exists?)
So, how do I actually load and display an image using NGraphics?
NGraphics does not provide any helpers to load images from your Platforms Resource files.
You could do something as follows. However, it will add some overhead converting back and forth between bitmap -> stream -> bitmap.
Android:
Stream GetDrawableStream(Context context, int resourceId)
{
var drawable = ResourcesCompat.GetDrawable(context.Resources, resourceId, context.Theme);
if (drawable is BitmapDrawable bitmapDrawable)
{
var stream = new MemoryStream();
var bitmap = bitmapDrawable.Bitmap;
bitmap.Compress(Bitmap.CompressFormat.Png, 80, stream);
bitmap.Recycle();
return stream;
}
return null;
}
iOS:
Stream GetImageStream(string fileName)
{
using (var image = UIImage.FromFile(fileName))
using (var imageData = image.AsPNG())
{
var byteArray = new byte[imageData.Length];
System.Runtime.InteropServices.Marshal.Copy(imageData.Bytes, byteArray, 0, Convert.ToInt32(imageData.Length));
var stream = new MemoryStream(byteArray);
return stream;
}
return null;
}
However, you could go directly from Bitmap to BitmapImage on Android instead like:
BitmapImage GetBitmapFromDrawable(Context context, int resourceId)
{
var drawable = ResourcesCompat.GetDrawable(context.Resources, resourceId, context.Theme);
if (drawable is BitmapDrawable bitmapDrawable)
{
var bitmap = bitmapDrawable.Bitmap;
return new BitmapImage(bitmap);
}
return null;
}
And on iOS:
CGImageImage GetImageStream(string fileName)
{
var iOSimage = UIImage.FromFile(fileName);
var cgImage = new CGImageImage(iOSImage.CGImage, iOSImage.Scale);
return cgImage;
}
BitmapImage and CGImageImage implement IImage in NGraphics.
I'm trying to implement an UI where the user can edit and apply effects to an uploaded image, and want to save the BlendMode merged to the image. It's possible to save the result of the blended image or apply it using the Canvas?
There are some packages that apply some specific filters, but I want something more customizable for the end user.
I already saw some examples of how to implement Canvas to draw images, but can't figure it out how to use to load an image an apply the blend related in the docs. Anyone could give an example?
UPDATED:
For who has the same question, bellow follows the code with how to save a image from canvas to a file with blendMode applied.
But I still haven't the result expected. The quality of the image generated isn't the same as the original image, neither the blend seems to be the blend that i've applied. And i can't save as jpg, just as png file.
So, how can i load an image, apply a blend with canvas and save as a jpg file, without losing quality?
CODE:
const kCanvasSize = 200.0;
class CanvasImageToFile {
CanvasImageToFile._();
static final instance = CanvasImageToFile._();
ByteData _readFromFile(File file) {
// File file = getSomeCorrectFile();
Uint8List bytes = file.readAsBytesSync();
return ByteData.view(bytes.buffer);
}
Future<File> _writeToFile(ByteData data) async {
String dir = (await getTemporaryDirectory()).path;
String filePath = '$dir/tempImage.jpg';
final buffer = data.buffer;
return new File(filePath).writeAsBytes(
buffer.asUint8List(data.offsetInBytes, data.lengthInBytes));
}
Future<ui.Image> _loadImageSource(File imageSource) async {
// ByteData data = await rootBundle.load(asset);
ByteData data = _readFromFile(imageSource);
ui.Codec codec = await ui.instantiateImageCodec(data.buffer.asUint8List());
ui.FrameInfo fi = await codec.getNextFrame();
return fi.image;
}
Future<File> generateImage(File imageSource) async {
File imageResult;
ui.Image image;
await _loadImageSource(imageSource).then((value) {
image = value;
});
if (image != null) {
final recorder = ui.PictureRecorder();
var rect =
Rect.fromPoints(Offset(0.0, 0.0), Offset(kCanvasSize, kCanvasSize));
final canvas = Canvas(recorder, rect);
Size outputSize = rect.size;
Paint paint = new Paint();
//OVERLAY - BlendMode uses the previously drawn content as a mask
paint.blendMode = BlendMode.colorBurn;
paint.color = Colors.red;
// paint.colorFilter = ColorFilter.mode(Colors.blue, BlendMode.colorDodge);
// paint = Paint()..color = Colors.red;
// paint = Paint()..blendMode = BlendMode.multiply;
//Image
Size inputSize = Size(image.width.toDouble(), image.height.toDouble());
final FittedSizes fittedSizes =
applyBoxFit(BoxFit.cover, inputSize, outputSize);
final Size sourceSize = fittedSizes.source;
final Rect sourceRect =
Alignment.center.inscribe(sourceSize, Offset.zero & inputSize);
canvas.saveLayer(rect, paint);
canvas.drawImageRect(
image, sourceRect, rect, paint);
canvas.restore();
final picture = recorder.endRecording();
final img = await picture.toImage(200, 200);
final byteData = await img.toByteData(format: ImageByteFormat.png);
await _writeToFile(byteData).then((value) {
imageResult = value;
});
return imageResult;
}
After some research e some adjust at decoding image from png to rawUnmodified in my previous code using (Bitmap package), i could save the image with the original format (jpg) and achieved what i wanted. If there's anyone who have the same question, bellow follows the code to load an image with canvas, apply a blend and write to a file with the same quality:
Future<File> generateImage(
File imageSource, Color color, BlendMode blendMode) async {
File imageResult;
ui.Image image;
await _loadImageSource(imageSource).then((value) {
image = value;
});
if (image != null) {
final recorder = ui.PictureRecorder();
var rect = Rect.fromPoints(Offset(0.0, 0.0),
Offset(image.width.toDouble(), image.height.toDouble()));
final canvas = Canvas(recorder, rect);
Size outputSize = rect.size;
Paint paint = new Paint();
//OVERLAY - BlendMode uses the previously drawn content as a mask
// paint.blendMode = blendMode;
// paint.color = color;
paint.colorFilter = ColorFilter.mode(color, blendMode);
//Image
Size inputSize = Size(image.width.toDouble(), image.height.toDouble());
final FittedSizes fittedSizes =
applyBoxFit(BoxFit.contain, inputSize, outputSize);
final Size sourceSize = fittedSizes.source;
final Rect sourceRect =
Alignment.center.inscribe(sourceSize, Offset.zero & inputSize);
canvas.drawImageRect(image, sourceRect, rect, paint);
final picture = recorder.endRecording();
final img = await picture.toImage(image.width, image.height);
ByteData byteData =
await img.toByteData(format: ui.ImageByteFormat.rawUnmodified);
Bitmap bitmap = Bitmap.fromHeadless(
image.width, image.height, byteData.buffer.asUint8List());
Uint8List headedIntList = bitmap.buildHeaded();
await _writeToFile(headedIntList.buffer.asByteData()).then((value) {
imageResult = value;
});
return imageResult;
}
}
I'm using Xamarin.Forms with Urhosharp in my project. I'm tring to set a matrial from an image on a sphere, everything is OK in my Android project but in iOS project, when I set material from some jpg files it doesn't work and all I get is a black screen.
Here is the jpg that works correctly:
And here is the other one that doesn't:
This is my code:
var scene = new Scene();
scene.CreateComponent<Octree>();
// Node (Rotation and Position)
var node = scene.CreateChild("room");
node.Position = new Vector3(0, 0, 0);
//node.Rotation = new Quaternion(10, 60, 10);
node.SetScale(1f);
// Model
var modelObject = node.CreateComponent<StaticModel>();
modelObject.Model = ResourceCache.GetModel("CustomModels/SmoothSphere.mdl");
var zoneNode = scene.CreateChild("Zone");
var zone = zoneNode.CreateComponent<Zone>();
zone.SetBoundingBox(new BoundingBox(-300.0f, 300.0f));
zone.AmbientColor = new Color(1f, 1f, 1f);
//get image from byte[]
//var url = "http://www.wsj.com/public/resources/media/0524yosemite_1300R.jpg";
//var wc = new WebClient() { Encoding = Encoding.UTF8 };
//var mb = new MemoryBuffer(wc.DownloadData(new Uri(url)));
var mb = new MemoryBuffer(PanoramaBuffer.PanoramaByteArray);
var image = new Image(Context) { Name = "MyImage" };
image.Load(mb);
//or from resource
//var image = ResourceCache.GetImage("Textures/grave.jpg");
var isFliped = image.FlipHorizontal();
if (!isFliped)
{
throw new Exception("Unsuccessful flip");
}
var m = Material.FromImage("1.jpg");
m.SetTechnique(0, CoreAssets.Techniques.DiffNormal, 0, 0);
m.CullMode = CullMode.Cw;
//m.SetUVTransform(Vector2.Zero, 0, 0);
modelObject.SetMaterial(m);
// Camera
var cameraNode = scene.CreateChild("camera");
_camera = cameraNode.CreateComponent<Camera>();
_camera.Fov = 75.8f;
_initialZoom = _camera.Zoom;
// Viewport
Renderer.SetViewport(0, new Viewport(scene, _camera, null));
I already tried to change compression level, ICCC profile and ...
I asked the same question in forums.xamarin.com and someone answered the question and I'll share it here :
In iOS every texture needs to have a power of two resolution, like 256 x 256 or 1024 x 512. Check if that is the issue. Additionally check that your using the latest UrhoSharp version.
Also make sure that the image is set as BundleResource in the iOS project.
I am having a tough time converting lumia imaging SDK 2.0 code to SDK3.0 in below specific case. I used to increase/decrease the image quality of JPG file using below code in Windows phone 8.1 RT apps:
using (StreamImageSource source = new StreamImageSource(fileStream.AsStreamForRead()))
{
IFilterEffect effect = new FilterEffect(source);
using (JpegRenderer renderer = new JpegRenderer(effect))
{
renderer.Quality = App.COMPRESSION_RATIO / 100.0; // higher value means better quality
compressedImageBytes = await renderer.RenderAsync();
}
}
Now since FilterEffect class has been replaced in SDK 3.0 with EffectList(), I changed code to
using (BufferProviderImageSource source = new BufferProviderImageSource(fileStream.AsBufferProvider()))
{
using (JpegRenderer renderer = new JpegRenderer())
{
IImageProvider2 source1 = new EffectList() { Source = source };
renderer.Source = source1;
renderer.Quality = App.COMPRESSION_RATIO / 100.0;
try
{
var img = await renderer.RenderAsync();
}
catch (Exception ex)
{
;
}
}
}
I am getting InvalidCastException exception. I have tried several combinations but no luck.
I don't really know what is going on with the InvalidCastException, we can continue that discussion in the comments as it will most likely need some back-and-forth.
That said, you could continue without the effect list, and chain effects in the normal way. So to rewrite your scenario:
using (var soruce = new StreamImageSource(...))
using (var renderer = new JpegRenderer(source))
{
renderer.Quality = App.COMPRESSION_RATIO / 100.0;
var img = await renderer.RenderAsync();
}
If you wanted to add an effect (for example a CarttonEffect), just do:
using (var soruce = new StreamImageSource(...))
using (var caroonEffect = new CartoonEffect(source))
using (var renderer = new JpegRenderer(caroonEffect))
{
renderer.Quality = App.COMPRESSION_RATIO / 100.0;
var img = await renderer.RenderAsync();
}
and so on. If you had effects A, B, C and D just make a chain Source -> A -> B -> C -> D -> JpegRenderer.
I am on VS 2015 community version. While digging around this, I got below code working which works exactly same as SDK 2.0. All I did was specified the Size of JpegRenderer. It works for all landscape images but fails to transform the portrait images to correct orientation. There is no exception but result of portrait image is widely stretched landscape image.
I initialized the Size for portrait images to Size(765, 1024) but no impact.
using (JpegRenderer renderer = new JpegRenderer(source))
{
renderer.Quality = App.COMPRESSION_RATIO / 100.0;
try
{
var info = await source.GetInfoAsync();
renderer.Size = new Size(1024, 765);
compressedImageBytes = await renderer.RenderAsync();
}
catch (Exception ex)
{
new MessageDialog("Error while compressing.").ShowAsync();
}
}
I am sorry the working code was using BufferProviderImageSource instead StreamImageSource. Below is the snippet. Few points here:
1) If I don't use Size property I get "The component cannot be found exception".
2) GetInfoAsync(): Yes it was useless for above code but I need to use it to know if image is Landscape or Portrait so that I can initialize Size property of resultant image.
3) If Size property goes beyond 1024x1024 for portrait images I get the exception "Value does not fall within the expected range"
Why lumia made this version so tricky. :(
var stream = FileIO.ReadBufferAsync(file);
using (var source = new BufferProviderImageSource(stream.AsBufferProvider()))
{
EffectList list = new EffectList() { Source = source };
using (JpegRenderer renderer = new JpegRenderer(list))
{
renderer.Quality = App.COMPRESSION_RATIO / 100.0;
renderer.OutputOption = OutputOption.PreserveAspectRatio;
try
{
var info = await source.GetInfoAsync();
double width = 0;
double height = 0;
if (info.ImageSize.Width > info.ImageSize.Height) //landscape
{
width = 1024;
height = 765;
if (info.ImageSize.Width < 1024)
width = info.ImageSize.Width;
if (info.ImageSize.Height < 765)
height = info.ImageSize.Height;
}
else //portrait..
{
width = 765;
height = 1024;
if (info.ImageSize.Width < 765)
width = info.ImageSize.Width;
if (info.ImageSize.Height < 1024)
height = info.ImageSize.Height;
}
renderer.Size = new Size(width, height);
compressedImageBytes = await renderer.RenderAsync();
}
catch (Exception ex)
{
new MessageDialog(ex.Message).ShowAsync();
}
}
}