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reading data uri with opencv.js

asked 2019-07-10 00:32:55 -0500

MaggPI gravatar image

HI , I would like to import an image data uri into opencv.js. Is there a factory function such as cv.imread to do this?

If not, are there any examples javascript routines that can sort the data uri into cv.matFromImageData?

Thank You

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can you show us, what you have, so far ? what are you trying to achieve ? what's the "context" ?

berak gravatar imageberak ( 2019-07-10 01:58:31 -0500 )edit

no js expert, but imho, you should load your image into a canvas, and use cv.matFromImageData from that.

(in the same way, imread() does it, just look at helper.js / utils.js)

berak gravatar imageberak ( 2019-07-10 03:17:52 -0500 )edit

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answered 2019-07-12 17:51:13 -0500

MaggPI gravatar image

Berak , thx for your note, I found a great site that explains datauri conversion options with opencv.js

// load base64 encoded image const base64text='data:image/png;base64,R0lGO..';//Base64 encoded string const base64data =base64text.replace('data:image/jpeg;base64','') .replace('data:image/png;base64','');//Strip image type prefix const buffer = Buffer.from(base64data,'base64'); const image = cv.imdecode(buffer); //Image is now represented as Mat

// convert Mat to base64 encoded jpg image const outBase64 = cv.imencode('.jpg', croppedImage).toString('base64'); // Perform base64 encoding const htmlImg=''; //Create insert into HTML compatible tag

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^^ none of it supported from opencv.

berak gravatar imageberak ( 2019-07-13 03:16:36 -0500 )edit

Hi cv.imencode is undefined. Do you know why?

wwwwwwwwwwww gravatar imagewwwwwwwwwwww ( 2020-10-20 12:45:49 -0500 )edit

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Asked: 2019-07-10 00:32:55 -0500

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Last updated: Jul 12 '19