Error when loading DICOM images, image with noise when using Arch Linux

[MuriloSchaefer]

Hi,

I'm using AMI.js with OHIF Viewer, and it was working fine in Ubuntu, but when I'm using Arch Linux, every image loaded came with some noise (see Figure 1), then I zoomed to see what is this noise, and discover that is like the image has been sliced in many rows, and between this rows there a space (Figure 2). The Figure is from lesson 1 example.

Figure 1

Figure 2

About the machine: I'm using an Intel i7, 8Gb of RAM, Google Chrome version 66 and Firefox 59 (both presented the same issue). When I run the script $uname -a I get: Linux Schaefer 4.16.3-1-ARCH #1 SMP PREEMPT Thu Apr 19 09:17:56 UTC 2018 x86_64 GNU/Linux

I believed that was an error with the three.js lib, but I can't reproduce the error with their examples, so I decided to post it here to see if I get some possible cause of this error.

Thank you, Murilo Schaefer

[NicolasRannou]

Interesting…

What is the same machine working fine in Ubuntu or a different machine?

On Apr 23, 2018, at 6:02 PM, MuriloSchaefer notifications@github.com wrote:

Hi,

I'm using AMI.js with OHIF Viewer, and it was working fine in Ubuntu, but when I'm using Arch Linux, every image loaded came with some noise (see Figure 1), then I zoomed to see what is this noise, and discover that is like the image has been sliced in many rows, and between this rows there a space (Figure 2). The Figure is from lesson 1 example.

Figure 1 https://user-images.githubusercontent.com/14366202/39138162-b668e660-46f5-11e8-8765-14ebf1dedc24.png Figure 2 https://user-images.githubusercontent.com/14366202/39138163-b6903134-46f5-11e8-8290-58cdc87f31a2.png About the machine: I'm using an Intel i7, 8Gb of RAM, Google Chrome version 66 and Firefox 59 (both presented the same issue). When I run the script $uname -a I get: Linux Schaefer 4.16.3-1-ARCH #1 SMP PREEMPT Thu Apr 19 09:17:56 UTC 2018 x86_64 GNU/Linux

I believed that was an error with the three.js lib, but I can't reproduce the error with their examples, so I decided to post it here to see if I get some possible cause of this error.

Thank you, Murilo Schaefer

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[MuriloSchaefer]

It's a different machine, but when I use the Windows 10 installed on the same machine from Arch, it works fine, using the same version of Google Chrome and Firefox.

[MuriloSchaefer]

ADD: When I open the lesson with the console opened, some warnings came up:

THREE.WebGLShader: gl.getShaderInfoLog() vertex 0:1(12): warning: extension 'GL_ARB_gpu_shader5' unsupported in vertex shader

THREE.WebGLShader: gl.getShaderInfoLog() fragment 0:1(12): warning: extension 'GL_ARB_gpu_shader5' unsupported in fragment shader

This message isn't shown in Google Chrome, only in Firefox. There are some topics in three.js repository about it and apparently, this is a Firefox issue, so I don't know if it's related if the bug.

And the following Warning:

Error: WebGL warning: texImage2D: Alpha-premult and y-flip are deprecated for non-DOM-Element uploads.

Which looks like a wontfix issue from Firefox: https://bugzilla.mozilla.org/show_bug.cgi?id=1400077

[NicolasRannou]

Hmm yes, this one is tough, I suspect some driver / graphic-card specific thing. Could you find a THREE example not working using the "problematic machine"?

[MuriloSchaefer]

So, I thought that's a driver problem and tried to re-install and update everything but nothing changed. I've tried to find a THREE example if the same bug and didn't find one, everything works, the problem only occurs with the ami.js textures.

I've start believe that the driver for this O.S doesn't support something, but I have no idea of what and what to do

[NicolasRannou]

Yes I think that may be a precision issue in the shaders, that is graphic card specific. That is a bug in AMI but a tough one to track down :)

[MuriloSchaefer]

Do you have any idea of what could I do to track?

[NicolasRannou]

It is tough - do you have experience with WebGL/ OpenGL?

[MuriloSchaefer]

So, no, just the basics