exporting the convert methods

[VerioN1]

I noticed that you need to convert the image to an array of 8bit luma data, or rgb before passing it to decode_barcode. why not also expose the methods that do that?
Maybe I'm wrong and you can do this in vanilla js, but I couldn't find any example that do that without installing zxing (for js).
If there are other ways to pass image from js to the decoding function without installing zxing, I will be happy to know .

[hschimke]

I'll have to look up what JS image data looks like (canvas, image, I don't remember?). If it's a byte stream with predictable layout I can expose a method to handle it no problem.

I have some enhancements I want to make to this library, including the ability to set encode and decode hints for JS requests.

Would it be find for the function to be "yet another decode" function, where you hand it the JS image data directly and it handles the conversion in the background, or would a two step process be better, where one method generates the byte stream, and another decodes it?

[VerioN1]

I guess exposing a function that handles the conversion of the image to what ever decode you use, should be preferable since you are decoupling it from the decoding function. exposing multiple such conversion methods can be even better.
IMO most use cases of this wasm, would be file uploading - so maybe knowing how to handle canvas or event base64, and exposing a method that can convert it to the data type of the barcode decoder - would be nice.

you can contact me and I can help you test and improve it.

[VerioN1]

this is somehting I wrote to manipulate the Image data so I can pass it to zxing in my js app :

reader.onload = async (e) => {
const canvas = document.getElementById('imageCanvas') as HTMLCanvasElement;
if (!canvas) return;
const img = new Image();
img.src = e?.target?.result as string;
img.onload = async () => {
canvas.width = img.width;
canvas.height = img.height;
const ctx = canvas.getContext('2d');
if (!ctx) return;
ctx.drawImage(img, 0, 0);
const result = await zxingDecodeCanvas(canvas);
console.log(result);
if (result?.error) reject(result as BarcodeScannerResult);
resolve(result as BarcodeScannerResult);
};
};

[hschimke]

Got it, I'll get familiar with this and get it implemented. I'm finishing up adding maxicode detection to rxing (zxing and rxing currently only support it in a "pure barcode" image) and then I'll get to this. Probably by the end of the week.

[hschimke]

please check out version 0.1.3 on npm https://www.npmjs.com/package/rxing-wasm and let me know if that meets your requirements.

[VerioN1]

tested it and indeed the function converts the image data properly (since im not getting not found error).
What is weird is that the return value of the decode_barcode isn't right. adding a picture of a successful decode:

[VerioN1]

as you can see the in the console log - the result only has ptr in it (which I guess is a memory pointer address maybe?)

[VerioN1]

I did tried to make it async and await those functions (just to see if anything changes) and it returned the same result

[hschimke]

I pushed another version, but it shouldn't make a huge difference here.

The result should be an object, could you try using the text() method on the object and seeing if you get what you're looking for?

[VerioN1]

ohh my bad. It worked!
Only thing left is to let us configure the hints :)

[hschimke]

It's there! Check out the new decode_barcode_with_hints function. It takes a DecodeHintDictionary object, which you can create as you would any object, and which has a set_hint method.

I haven't written any documentation for it yet, so let me know if you have issues.

[VerioN1]

great! will you make a NPM lib with it?, or , if you don't have the time to handle it, I can make a lib out of it.

[hschimke]

https://www.npmjs.com/package/rxing-wasm