I discovered AForge a few days ago with a goal in mind. I wanted to be able to manipulate an image's colors. However, after trying several different methods I have not been able to find a resolution.
I looked thoroughly through the documentation they give, but it hasn't been any help to me. The specific part of the documentation I have been using is:
http://www.aforgenet.com/framework/docs/html/3aaa490f-8dbe-f179-f64b-eedd0b9d34ac.htm
The example they give:
// create filter
YCbCrLinear filter = new YCbCrLinear( );
// configure the filter
filter.InCb = new Range( -0.276f, 0.163f );
filter.InCr = new Range( -0.202f, 0.500f );
// apply the filter
filter.ApplyInPlace( image );
I replicated it for a button click event, but the 'image' portion of it wasn't specified. I converted the image inside of my picturebox to a bitmap, then referenced it in the last line thinking that it would work. But it had no affect at all.
My code is the following:
private void ColManButton_Click(object sender, EventArgs e)
{
Bitmap newimage = new Bitmap(pictureBox1.Image);
YCbCrLinear filter = new YCbCrLinear();
filter.InCb = new Range(-0.276f, 0.163f);
filter.InCr = new Range(-0.202f, 0.500f);
filter.ApplyInPlace(newimage);
}
My question essentially is, to anyone familiar or willing to help with this framework, how do I take my image and manipulate its color using AForge's YCbCrLinear Class under my button's click event?
Remember to set the picture box image after you have applied the filtering.
private void ColManButton_Click(object sender, EventArgs e)
{
Bitmap newimage = new Bitmap(pictureBox1.Image);
YCbCrLinear filter = new YCbCrLinear();
filter.InCb = new Range(-0.276f, 0.163f);
filter.InCr = new Range(-0.202f, 0.500f);
filter.ApplyInPlace(newimage);
pictureBox1.Image = newimage;
}
at the aforge website you can download the source code of a sample filter application, did you try it ?
Related
This is quite vexing.
I am working on an app for image management. Part of the value is the ability to store images in sub-folders based on image properties, eg. creation date.
If I store the image source in a shallow folder (app\images\img.jpg), everything works fine.
If I store the image in KnownFolders.Pictures\source\year\month\day\img.jpg, Image does not render. (Yes, that specific path won't work, I am trying to give you a sense of how the path is constructed)...
The file is actually there. The path is correct (I can open it in a browser, e.g.). The app has access to the file.
But it does not render the bitmap.
I tried to render the bitmap manually using
new BitmapImage(new Uri("KnownFolders.Pictures\source\year\month\day\img.jpg"),UriKind.Absolute))
That does not render anything. (Again, assume the path is valid and has a file at its bottom).
What Am I Missing?
The head scratcher: for GIF anims, I am using Thomas Levesque's useful component: https://github.com/XamlAnimatedGif. That one, unfortunately, does only render gifs... and it does so even when the path is the one given above. So the Standard IMAGE control does not render correctly, but Thomas's control does... infuriating.
An UWP app can't load a BitmapImage from an absolute URL to a file in a folder structure below the Pictures Library Folder.
So this won't work:
var relativePath = #"source\year\month\day\img.jpg";
var imageFile = await KnownFolders.PicturesLibrary.GetFileAsync(relativePath);
var bitmapImage = new BitmapImage(new Uri(imageFile.Path));
However, you could do this:
var relativePath= #"source\year\month\day\img.jpg";
var imageFile = await KnownFolders.PicturesLibrary.GetFileAsync(relativePath);
var bitmapImage = new BitmapImage();
using (var stream = await imageFile.OpenAsync(FileAccessMode.Read))
{
await bitmapImage.SetSourceAsync(stream);
}
So, after way too much time spent on this...
First, link to DataContextChanged of the IMAGE element. In there, parse the DataContext out. If you are using the IMAGE outside of an ItemsControl etc, this is not required...
private async void ImageView_DataContextChanged(FrameworkElement sender, DataContextChangedEventArgs args)
{
if (sender is Image)
{
Image img = (Image)sender;
if (img.DataContext is ImageView)
{
MyViewDataContext dc = (MyViewDataContext)img.DataContext;
img.Source = await dc.bitmap();
}
}
}
And here the implementation of MyViewDataContext.bitmap() which has a property called source that yields, you guessed it, absolute paths:
public async Task<BitmapImage> MyViewDataContext.bitmap()
{
if (_bitmap == null)
{
try
{
StorageFile file = await StorageFile.GetFileFromPathAsync(source);
bool r = Windows.Storage.AccessCache.StorageApplicationPermissions.FutureAccessList.CheckAccess(file);
if (r)
{
using (IRandomAccessStream fileStream = await file.OpenAsync(Windows.Storage.FileAccessMode.Read))
{
// create a new bitmap, coz the old one must be done for...
_bitmap = new BitmapImage();
// And get that bitmap sucked in from stream.
await _bitmap.SetSourceAsync(fileStream);
}
}
}
catch (Exception e)
{
_bitmap = null;
}
}
return _bitmap;
}
BitmapImage _bitmap;
I cache the resulting bitmap until I dispose of this MyViewDataContext.
I am now most concerned about memory. This one worries me:
How to dispose BitmapImage cache?
So, as a tech debt, I am going to address the potential mem leaks later, once this whole thing is on the test bench and I can take a look at its runtime behavior...
To access the folders and libraries represented by the properties of this class, specify the corresponding capabilities in your app manifest. For example, to access KnownFolders.PicturesLibrary, specify the Pictures Library capability in the app manifest.
Hope this will help
KnowFolders
I am working on a feature for my Android app. I would like to read text from a picture then save that text in a database. Is using OCR the best way? Is there another way? Google suggests in its documentation that NDK should only be used if strictly necessary but what are the downfalls exactly?
Any help would be great.
you can use google vision library for convert image to text, it will give better output from image.
Add below library in build gradle:
compile 'com.google.android.gms:play-services-vision:10.0.0+'
TextRecognizer textRecognizer = new TextRecognizer.Builder(getApplicationContext()).build();
Frame imageFrame = new Frame.Builder()
.setBitmap(bitmap) // your image bitmap
.build();
String imageText = "";
SparseArray<TextBlock> textBlocks = textRecognizer.detect(imageFrame);
for (int i = 0; i < textBlocks.size(); i++) {
TextBlock textBlock = textBlocks.get(textBlocks.keyAt(i));
imageText = textBlock.getValue(); // return string
}
From this Simple example of OCRReader in Android tutorial you can read text from image and also you can scan for text using camera, using very simple code.
This library is developed using Mobile Vision Text API
For scan text from camera
OCRCapture.Builder(this)
.setUseFlash(true)
.setAutoFocus(true)
.buildWithRequestCode(CAMERA_SCAN_TEXT);
For extract text from image
String text = OCRCapture.Builder(this).getTextFromUri(pickedImage);
//You can also use getTextFromBitmap(Bitmap bitmap) or getTextFromImage(String imagePath) buplic APIs from OCRLibrary library.
Text from an image can be extracted using Firebase machine learning (ML) kit. There are two versions of the text recognition API, on-device API (free) and on-cloud API.
To use the API, first create BitMap of the image, which should be upright. Then create FirebaseVisionImage object passing the bitmap object.
FirebaseVisionImage image = FirebaseVisionImage.fromBitmap(bitmap);
Then create FirebaseVisionTextRecognizer object.
FirebaseVisionTextRecognizer textRecognizer = FirebaseVision.getInstance()
.getCloudTextRecognizer();
Then pass the FirebaseVisionImage object to processImage() method, add listeners to the resulting task and capture the extracted text in success callback method.
textRecognizer.processImage(image)
.addOnSuccessListener(new OnSuccessListener<FirebaseVisionText>() {
#Override
public void onSuccess(FirebaseVisionText firebaseVisionText) {
//process success
}
})
.addOnFailureListener(new OnFailureListener() {
#Override
public void onFailure(#NonNull Exception e) {
//process failure
}
});
For complete example which shows how to use Firebase ML text recognizer, see https://www.zoftino.com/extracting-text-from-images-android
There is a different option. You can upload your image to the server, OCR it from the server, then get the result.
I have some images that are stored in Media Libary, view here. Now I need to get the name of an image after I choose the image by using photo chooser task. I used photo chooser task to select an image and then got the path of the image. My pupose is get the name from the path:
private void button1_Click(object sender, RoutedEventArgs e)
{
PhotoChooserTask objPhotoChooser = new PhotoChooserTask();
objPhotoChooser.Completed += new EventHandler<PhotoResult>(PhotoChooseCall);
objPhotoChooser.Show();
}
void PhotoChooseCall(object sender, PhotoResult e)
{
switch (e.TaskResult)
{
case TaskResult.OK:
BinaryReader objReader = new BinaryReader(e.ChosenPhoto);
image1.Source = new BitmapImage(new Uri(e.OriginalFileName));
MessageBox.Show("Photo's name: " + e.OriginalFileName.ToString());
break;
case TaskResult.Cancel:
MessageBox.Show("Cancelled");
break;
case TaskResult.None:
MessageBox.Show("Nothing Entered");
break;
}
}
Output:
Photo's name: \Applications\Data\C80566AB-E17E-495C-81A1-3FCAE34D3DEDE\Data\PlatformData\PhotoChooser-a8208960-3597-40fc-9b4f-869afcf822b6.jpg
After I choose the same image. The name of it will change (PhotoChooser-a8208960-3597-40fc-9b4f-869afcf822b6.jpg will change). I think it's not the name of the photo.
So:
Can we get the name of the image?
And how do we do?
You can get the actual file names. Use the MediaLibrary for that:
MediaLibrary lib = new MediaLibrary();
var collection = lib.RootPictureAlbum;
foreach (var p in collection.Albums[0].Pictures)
Debug.WriteLine(p.Name);
Notice that I am specifying the album index inside the root picture album. 0 will be for sample pictures, and so on. If you need to grab the contents of the image, just use p.GetImage(); to get the readable stream.
No. You cannot get the name of the file as it is in the pictures hub. You are given a copy of the stream and that has a different, temporary, name.
I want to load images into a Pivot header to substitute the lack of a Gallery control in WP7. I'm trying to populate them from a URL, and want to make sure that the image is not kept in the cache (by setting UriSource = null) to make sure that they don't take too much resources.
There's no way to do this in the XAML itself, can someone give me sample code to handle this from code-behind. my attempts have been unsuccessful. what am I doing wrong here?
public class PhotoGalleryVM
{
public ObservableCollection<BitmapImage> Images
{
get
{
ObservableCollection<BitmapImage> list = new ObservableCollection<BitmapImage>();
foreach (RoomImage r in App.appData.currentChoices.roomImages)
{
BitmapImage img = new BitmapImage(new Uri(Uri.UnescapeDataString(r.largeUri)));
img.UriSource = null;
list.Add(img);
}
return list;
}
}
}
There is an option that enables to ignore image cache:
bitmapImage.CreateOptions = BitmapCreateOptions.IgnoreImageCache;
Read more at msdn
I am trying to add photos to my game through photochooser.
I am using all the right usings (images, shell, etc.) but can't get to the bitmap class
What am I missing?
Update:
I tried using System.Windows.Media.Imaging.
and still can't find the bitmapimage class.
I can't find using System.Windows.dll.
can you be more specific? I get a sgwigly line below bitmapImage.
void photoChooserTask_Completed(object sender, PhotoResult result)
{
if (result.TaskResult == TaskResult.OK)
{
var bitmapImage=new
System.Windows.Media.Imaging.BitmapImage bmp =
new System.Windows.Media.Imaging.BitmapImage();
bmp.SetSource(result.ChosenPhoto);
}
}
If you're trying to use System.Bitmap then this isn't supported on the phone.
You probably want System.Windows.Media.Imaging.BitmapImage (in System.Windows.dll) instead.