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.
Related
In the end, my goal is to send a raw image data from the front-end, then split that image into however many pages, and lastly send that pdf back to the front-end for download.
But every time I use the theDoc.addImageFile(), it tells me that the "Image is not in a suitable format". I'm using this as reference: https://www.websupergoo.com/helppdfnet/source/5-abcpdf/doc/1-methods/addimagefile.htm
To troubleshoot, I thought that the image might not be rendering correctly, so I added a File.WriteAllBytes to view the rendered image and it was exactly what I wanted, but still not adding to the PDF. I also tried sending the actual path of a previously rendered image thinking that the new image might not have been fully created yet, but it also gave me the same error. Lastly, I thought PNGs might be problematic and changed to JPG but it did not work.
Here is the code:
[HttpPost]
public IActionResult PrintToPDF(string imageString)
{
// Converts dataUri to bytes
var base64Data = Regex.Match(imageString, #"data:image/(?<type>.+?),(?<data>.+)").Groups["data"].Value;
var binData = Convert.FromBase64String(base64Data);
/* Ultimately will be removed, but used for debugging image */
string path = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
string imgName= "Test.jpg";
string filename = Path.Combine(path, imgName);
System.IO.File.WriteAllBytes(filename, binData);
/***********************************************************/
using (Doc theDoc = new Doc())
{
// Using explicit path
theDoc.AddImageFile(#"C:\Users\User\Documents\Test.jpg", 1);
// Using variable
//theDoc.AddImageFile(filename, 1);
// What I really want
//theDoc.AddImageFile(binData , 1);
theDoc.Page = theDoc.AddPage();
theDoc.AddText("Thanks");
Response.Headers.Clear();
Response.Headers.Add("content-disposition", "attachment; filename=test.pdf");
return new FileStreamResult(theDoc.GetStream(), "application/pdf");
}
}
Try something like this (not tested, but cleaned up from my own code):
public int AddImageFile(Doc doc, byte[] data, int insertBeforePageID)
{
int pageid;
using (var img = new XImage())
{
img.SetData(data);
doc.Page = doc.AddPage(insertBeforePageID);
pageid = doc.Page;
doc.AddImage(img);
img.Clear();
}
return pageid;
}
To add a JPEG from a byte array you need Doc.AddImageData instead of Doc.AddImageFile. Note that AddImageFile / AddImageData do not support PNG - for that you would definitely need to use an XImage. The XImage.SetData documentation has the currently supported image formats.
I've an IFormFile image file (from postman as form data), which I convert into byte array. Before converting it into byte array, I want to rotate it into its actual position (if user input image as 90°(right). I'm implementing web api in asp.net core 2.0.
byte[] ImageBytes = Utils.ConvertFileToByteArray(model.Image);
public static byte[] ConvertFileToByteArray(IFormFile file)
{
using (var memoryStream = new MemoryStream())
{
file.CopyTo(memoryStream);
return memoryStream.ToArray();
}
}
Any help, Thanks in advance.
In my project I need to crop and resize the images users upload. And I am using a fantastic library called ImageSharp from Six Labors. You can use its image processor to do the transformation such as Resize, Crop, Skew, Rotate and more!
Install via NuGet
I am actually using their nightly build through MyGet.
Visual Studio -> Tools -> Options -> NuGet Package Manager -> Package Sources
Hit the "Plus" button to add a new package resource
I typed "ImageSharp Nightly" as the name and put "https://www.myget.org/F/sixlabors/api/v3/index.json" as the source url.
On Browse, search "SixLabors.ImageSharp" (In my case I also need "SixLabors.ImageSharp.Drawing" but in your case you might only need to core library. Always refer back to their documentations).
Crop & Resize
using SixLabors.ImageSharp;
using SixLabors.ImageSharp.Formats;
using SixLabors.ImageSharp.Processing;
using SixLabors.ImageSharp.Processing.Transforms;
using SixLabors.Primitives;
using System.IO;
namespace DL.SO.Project.Services.ImageProcessing.ImageSharp
{
public CropAndResizeResult CropAndResize(byte[] originalImage,
int offsetX, int offsetY, int croppedWidth, int croppedHeight,
int finalWidth, int finalHeight) : IImageProcessingService
{
IImageFormat format;
using (var image = Image.Load(originalImage, out format))
{
image.Mutate(x => x
// There is .Rotate() you can call for your case
.Crop(new Rectangle(offsetX, offsetY, croppedWidth, croppedHeight))
.Resize(finalWidth, finalHeight));
using (var output = new MemoryStream())
{
image.Save(output, format);
// This is just my custom class. But see you can easily
// get the processed image byte[] using the ToArray() method.
return new CropAndResizeResult
{
ImageExtension = format.Name,
CroppedImage = output.ToArray()
};
}
}
}
}
Hope this helps you - from a big fan of ImageSharp library!
Magick.NET, The ImageMagick wrapper for .Net Core can be used for many file manipulations, see https://github.com/dlemstra/Magick.NET
byte[] byt = System.IO.File.ReadAllBytes(filePath);
System.IO.MemoryStream ms = new System.IO.MemoryStream(byt);
using (Image img = Image.FromStream(ms))
{
RotateFlipType r = angle == 90 ? RotateFlipType.Rotate90FlipNone : RotateFlipType.Rotate270FlipNone;
img.RotateFlip(r);
img.Save(filePath);
}
Using your existing code you can do the following
I'm trying to upload an image from xamarin.forms and using restsharp for api service.
RestRequest uploadPostRestRequest = new RestRequest("post/create/", Method.POST);
uploadPostRestRequest.AddJsonBody(uploadPostRequest);
and this is my model UploadPostRequest
public class UploadPostRequest
{
public string content;
public byte[] image;
}
Question - Is it right to set image type as byte[]?
Would server accept this or would restsharp manage it?
If RestSharp has a nice control with this, can I just put MediaFile from Xam.Plugin.Media so I can upload it right over?
Xam.Plugin.Media is used for picking images from mobile device.
Too many options, so, that's why I'm looking for good advice.
Has anyone experienced this same issue before? please help.
For additional info, I cant use System.IO.File, Xamarin.Forms wont let me use it.
When the Xam.Plugin.Media finish loading the media either from the Camera or from the Library it returns a MediaFile. This object can be converter to a byte array with something like this:
byte[] byteArray;
using (var memoryStream = new MemoryStream ())
{
mediaFile.GetStream ().CopyTo (memoryStream);
mediaFile.Dispose ();
byteArray = memoryStream.ToArray ();
}
Now you have the byte array you just need to pass it to the method that will upload the image to your backend.
I am loading image from script to texture from URL. It is loading successfully, but the image is not reflecting on the texture.
How can I fix this?
you should UV unwrapped your model(that you want to put your image on it as a texture) you save the uv and then import it to unity then you can apply texture to it , here is tutorial that will show you how to do it in blender
Alright, if I'm gathering from the image correctly, it looks like you're using NGUI. If so, then you don't use Mesh Renderer. It's been a little bit since I used NGUI, but you need a reference to the game object or to the UITexture component that is on the game object. So I'll provide some code samples below for both scenarios. But you don't use a mesh renderer unless you're wrapping the texture around a 3D model. If this is for the UITexture then you would attach the image on there.
Game Object Reference:
imageObject.GetComponent<UITexture>().mainTexture = textureToUse;
UITexture Reference:
uiTextureReference.mainTexture = textureToUse;
I think that is what you were looking for, otherwise you need to do unwrapping and what not.
It is very easy if you are using NGUI.
Create a UITexture.
Refer it in you class either by declaring it public variable of getting it at runtime.
Import MiniJSON class that is easily available on internet. (Do not hesitate if you failed to find MiniJSON.Json, it could be MiniJSON.Deserialize or only Json.Deseiralize)
Following is the code snippet to get Facebook Display Picture with User_API_ID
string myImageUrl = "https://graph.facebook.com/"+API_ID+"/picture?type=large&redirect=0";
WWW myImageGraphRequest = new WWW(myImageUrl);
yield return myImageGraphRequest;
if (!string.IsNullOrEmpty(myImageGraphRequest.error))
Debug.Log("Could not fetch own User Image due to: " + myImageGraphRequest.error);
else
{
var myImageData = MiniJSON.Json.Deserialize (myImageGraphRequest.text) as Dictionary<string, object>;
var myImageLinkWithData = myImageData["data"] as Dictionary<string, object>;
string myImageLink = (string)myImageLinkWithData["url"];
WWW myImageRequest = new WWW(myImageLink);
yield return myImageRequest;
if (!string.IsNullOrEmpty(myImageRequest.error))
Debug.Log("Could not get user facebook image: " + myImageRequest.error);
else
{
userDP.mainTexture = myImageRequest.texture;
}
}
userDP is your UITexture.
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