SvgQRCode with logo and disable quitzones has a hole

[TheBlubb14]

Type of issue

• Bug
• Question (e.g. about handling/usage)
• Request for new feature/improvement

Expected Behavior

When generating a graphic with SvgQRCode, using a logo and disabling the quitezones. The logo is in the middle of the qr code and the qr code is intact.

Current Behavior

There is a "hole" in the top left area of the qr code and the image overlaps pixels.

Steps to Reproduce (for bugs)

I have setup a simple blazor web ui here: https://theblubb14.github.io/QrCoderBlazor/
Source code is available here: https://github.com/TheBlubb14/QrCoderBlazor/blob/main/QrCoderBlazor/App.razor
Sample logo you can download from here: https://avatars.githubusercontent.com/u/94650532

1. Download the above logo and select it in the ui for upload
2. Disable the checkbox quiet zones
3. Enter one letter in the input
4. Click the button generate

Your Environment

• Version used: 1.4.3
• Compiled from source or NuGet package?: Use latest available nuget package and copied SvgQRCode from source as the new changes to add a logo are not yet available via nuget. I removed some constructors which where not compatible and removed the #ifs to make it run under .net 8
• Payload/Encoded text: a
• Used ECC-level: M
• Used renderer class: SvgQRCode
• Environment: net8.0 blazor webassembly

[Shane32]

Looks like perhaps the SvgQRCode class was supposed to clear an area below the image, but the calculation is off - probably due to the quiet zones.

Can you reproduce the issue in a simple console application? It would be most convenient if you could post a simple snippet of code that reproduces the effect along with attaching the image you are using for the logo. Then it should be simple to fix.

[codebude]

Seems to be the IsBlockedByLogo function that doesn't take the quiet zones into consideration:
https://github.com/codebude/QRCoder/blob/master/QRCoder/SvgQRCode.cs#L213

@TheBlubb14 can you try to set fill background to false in the SvgLogo object and check if the "hole" is gone then?

By the way - you don't have to compile from source. The latest commits are available via the CI packages: https://github.com/codebude/qrcoder/packages

[TheBlubb14]

Looks like perhaps the SvgQRCode class was supposed to clear an area below the image, but the calculation is off - probably due to the quiet zones.

Can you reproduce the issue in a simple console application? It would be most convenient if you could post a simple snippet of code that reproduces the effect along with attaching the image you are using for the logo. Then it should be simple to fix.

using QRCoder;

var base64Img = "iVBORw0KGgoAAAANSUhEUgAAADIAAAAyBAMAAADsEZWCAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAADUExURf8AABniCTcAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAAUSURBVDjLYxgFo2AUjIJRAAUMDAAFFAABr92aEgAAAABJRU5ErkJggg==";
using var ms = new MemoryStream(Convert.FromBase64String(base64Img));
var qrCodeData = QRCodeGenerator.GenerateQrCode("a", QRCodeGenerator.ECCLevel.M);
var logo = new SvgQRCode.SvgLogo(new System.Drawing.Bitmap(ms));
var svg = new SvgQRCode(qrCodeData);
var rendered = svg.GetGraphic(24, "#000000", "#FFFFFF", false, SvgQRCode.SizingMode.ViewBoxAttribute, logo);
Console.WriteLine(rendered);
//File.WriteAllText("logo.svg", rendered);

[TheBlubb14]

Seems to be the IsBlockedByLogo function that doesn't take the quiet zones into consideration: https://github.com/codebude/QRCoder/blob/master/QRCoder/SvgQRCode.cs#L213

@TheBlubb14 can you try to set fill background to false in the SvgLogo object and check if the "hole" is gone then?

By the way - you don't have to compile from source. The latest commits are available via the CI packages: https://github.com/codebude/qrcoder/packages

Setting fillLogoBackground to false resolves the issue. So there is an issue in the calculation i guess.

I cannot access your CI nuget packages from github as the asset link to the nupkg is not clickable. I believe that only people with write access to this repo can download the packages.

[Shane32]

@TheBlubb14 GitHub Packages unfortunately requires authentication for both public and private repositories.

See: https://docs.github.com/en/packages/learn-github-packages/about-permissions-for-github-packages

[Shane32]

So to clarify, you have access -- it is public -- but you still need to use a GitHub PAT to authenticate.

[TheBlubb14]

So to clarify, you have access -- it is public -- but you still need to use a GitHub PAT to authenticate.

Thanks now it is working with the CI packages.
I tried this before, but i only added my github registry, not the codebude one..

[codebude]

@TheBlubb14 Should be fixed with the latest build. If you still experience faulty behaviour feel free to re-open the issue

[TheBlubb14]

@TheBlubb14 Should be fixed with the latest build. If you still experience faulty behaviour feel free to re-open the issue

Its fixed, thanks