QR Codes with images losing data when converting to byte[]

[Sdraugel]

Type of issue

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

Expected Behavior

I expect the generated QR code to look like this but have the logo in the middle.

Current Behavior

This is currently what is output if adding a logo.

Steps to Reproduce (for bugs)

Here is my code for generating a QR Code with a logo

private async Task<byte[]> GetLogoQRCode(string url, string darkColorHex, string logoUrl)
        {
            PayloadGenerator.Url generator = new PayloadGenerator.Url(url);
            string payload = generator.ToString();
            using (var qrGenerator = new QRCodeGenerator())
            using (var qrCodeData = qrGenerator.CreateQrCode(payload, QRCodeGenerator.ECCLevel.Q))
            using (var qrCode = new QRCode(qrCodeData))
            using (var stream = new MemoryStream())
            {
                // Grab an image from the internet and convert it to a Bitmap
                var logo = await _webHelper.GetImageFromWeb(logoUrl);
                // Convert a Hex string into a Color
                var darkColor = ColorTranslator.FromHtml(darkColorHex);
                var qrCodeImage = qrCode.GetGraphic(20, darkColor, Color.White, logo, 20);
                qrCodeImage.Save(stream, System.Drawing.Imaging.ImageFormat.Bmp);
                var result = stream.ToArray();
                return result;
            }
        }

Your Environment

• OS: macOS Mojave Version 10.14.6
• Version used: 1.3.5
• Compiled from source or NuGet package?: Nuget
• Payload/Encoded text: payload
• Used payload generator: yes
• Used ECC-level:
• Used renderer class:
• Environment (.NET 3.5, .NET 4.X, .NETCore, ...): .NET 2.2

[Sdraugel]

#210

[Sdraugel]

The problem is this line

QRCoder/QRCoder/QRCode.cs

Line 105 in 60217f8

region.Exclude(iconPath);

I removed that line and now QR codes, with logos, generate correctly.

[manikata0]

Great! can you please create pull request so codebude can release it

[codebude]

@Sdraugel have you tried this with transparent logos? (e.g. a png graphic with alpha transparent channel) If I remember correctly I added the region.Exclude to build "whitespace" in the size of the logo graphics, so that the logo can be seen clearly. I guess without the region.Exclude it could be hard to see logos with a transparent background.

[Sdraugel]

@codebude It does get rid of the white background but a side effect of using region.Exclude is a lot of lost data for Linux and Mac. You can still see a png with alpha transparency fine, as long as it isn't a solid color that's the same as the background or foreground.

Here is one I generated:

My suggestion, if you want to add a white background, is to add it to the passed in png. This will prevent the region.Exclude side bug and still achieve your desired look.

[abrari]

Waiting this fix to be released to nuget

[Simon311]

@codebude I mean, people could just add a white background of any shape into their logo. I did it (using a white circle) and I am totally happy with the result. Right now I am using a workaround to draw it over the QR code, but this fix will genuinely improve people's experience with the library.

[johnboker]

How's it going with the fix for this?

[codebude]

Hi @Sdraugel , @manikata0 , @Simon311 @johnboker , @abrari - thanks for you support and pushing me again and again to merge this. I really apologize for the long response times. That's not how it should work out usually. Thus thanks again for being patient! :-)