PNG images with 16bpp aren't supported by libgdiplus

[lennylxx]

Related https://github.com/dotnet/corefx/issues/33951

---

I'm using System.Drawing.Common on Ubuntu, there is exception when loading a 16bit png file.

** (process:10021): WARNING **: 17:41:57.195: PNG images with 16bpp aren't supported by libgdiplus.

Unhandled Exception: System.ArgumentException: Image format is unknown.
   at System.Drawing.Bitmap..ctor(String filename, Boolean useIcm)
   at debug.Program.Main(String[] args) in /home/user/debug/Program.cs:line 10

Ubuntu versions: OS: Ubuntu 18.04.1 LTS Kernel: 4.15.0-39-generic x86_64 dotnet: 2.1.500 System.Drawing.Common: 4.6.0-preview.18571.3 libpng16: 1.6.34-1ubuntu0.18.04.1 libgdiplus: 4.2-2

However, there is no exception when I test the same image on CentOS.

CentOS Versions: OS: CentOS 7 Kernel: 3.10.0-514.21.1.el7.x86_64 dotnet: 2.1.500 System.Drawing.Common: 4.6.0-preview.18571.3 libpng: libpng-1.5.13-7.el7_2.x86_64 libgdiplus: libgdiplus-2.10-10.el7.x86_64

Sample code:

using System;
using System.Drawing;

namespace debug
{
    class Program
    {
        static void Main(string[] args)
        {
            Bitmap bmp = new Bitmap("16bit_Gray16.png");
            Console.WriteLine(bmp.Height);
        }
    }
}

Sample image:

[EgorBo]

I guess it should be fixed here https://github.com/mono/libgdiplus/blob/bbd132a0ad01b1f514836b40fe49e23e0ef6b3da/src/pngcodec.c#L459 it should be if (channels * bit_depth >= 48) {

[lennylxx]

@EgorBo so, does it mean that 48bpp is still not supported after the fixed? I have another image that can be load on CentOS while not on Ubuntu.

libpng warning: iCCP: known incorrect sRGB profile

** (process:12405): WARNING **: 11:26:57.707: PNG images with 48bpp aren't supported by libgdiplus.

Unhandled Exception: System.ArgumentException: Image format is unknown.
   at System.Drawing.Bitmap..ctor(String filename, Boolean useIcm)
   at debug.Program.Main(String[] args) in /home/user/debug/Program.cs:line 10

[djbios]

Any progress on this one? My case:

** (process:1): WARNING **: PNG images with 64bpp aren't supported by libgdiplus.

[xhafan]

Due to PNG images with 48bpp aren't supported by libgdiplus issue on Linux I switched my .NET Core image resizing implementation to use ImageSharp based on this article. Had to install libgdiplus into my docker image though, even for ImageSharp.

[qmfrederik]

(Partial) support for 48bpp and 64bpp PNG images was implemented in #49 about two years ago. Are you using the latest version of libgdiplus (currently 6.0.1)?

[xhafan]

I checked a log, and Amazon Linux amzn2-ami-ecs-hvm-2.0 (apparently based on Debian) is downloading is version 4.2-1+b1.

[elgerm]

Guys, is this correct? https://packages.ubuntu.com/bionic/libgdiplus The latest version is apparently 4.2.2 (not 6.0.x) on ubuntu 18.04 lts.

[qmfrederik]

Yes. Use the Mono Ubuntu repositories to get a newer version of libgdiplus.

[elgerm]

Yes. Use the Mono Ubuntu repositories to get a newer version of libgdiplus.

Do you mean install mono to get libgdiplus 6? I'm using libgdiplus with aspnet core in a production environment to scale images. Installing mono with it feels a bit much

[qmfrederik]

You don't need to install Mono. But the package repositories for Mono contain an updated version of libgdiplus.

Alternatively, Ubuntu 20.04 should ship with libgdiplus 6.