Using Image Data

[mikolaskova]

Hello, 

I want to work with the image data of a jpeg-image like in this example:

https://www.w3schools.com/tags/tryit.asp?filename=tryhtml5_canvas_getimagedata2

On a webserver it works fine, but if I test locally I get an error

Quote

index.html:16 Uncaught DOMException: Failed to execute 'getImageData' on 'CanvasRenderingContext2D': The canvas has been tainted by cross-origin data.

Isn't it possible to work locally? How do I have to change the script in order to run it locally?

I will work with my (young) students with javascript and would like to work locally.

Best Regards

[Ingolme]

Browsers have security in place to prevent local scripts from mining information from the user's computer. Aside from that, if the image you are loading is not on your computer then the cross-origin protection will apply.

I would suggest installing server software, such as XAMPP, on your computer.