Allow task to request data using quality=original

My actions before raising this issue

• Read/searched the docs
• Searched past issues

We have projects with large (5MP) images. There is a significant delay loading new images if a new chunk needs to be requested, even locally. When the page requests a new chunk it uses something like: api/v1/tasks/68/data?type=chunk&number=2&quality=compressed

Looking at the network logs, there are two parts to the delay: waiting for a response and downloading the data. On a local connection, the delay is mostly due to waiting for a response.

If I make a request manually using quality=original, the delay waiting for a response is almost zero.

• Is there all ready an option when creating a task to make it use quality=original? I tried all permutations of the settings and couldn’t find a combination that worked.
• If not, could this option be added? (Which area of the code do I need to look to change this?)

[nmanovic]

@geometrikal , you see the overhead because chunks are created on the fly. When you create a task, you can uncheck “Use cache” in advanced options. CVAT will prepare all necessary data when a task is created. The primary idea behind “Use cache” is to reduce consumption of disk space, reduce time to create a task.

[geometrikal]

@nmanovic Thanks for your reply and for the work on CVAT.

Unfortunately our datasets are very large (> 1TB and growing) and are regularly updated so we have to use the cache. (We are using CVAT as the front end for annotating large environmental datasets - can discuss offline)

I found where to change the code (line 824 in https://github.com/openvinotoolkit/cvat/blob/develop/cvat-core/src/server-proxy.js) and now it works well for internal use (e.g. fast network)

If this could be made an option in the task creation that would be great. Hopefully we can make the changes ourselves and submit a pull request. Another wish would be that CVAT pre-caches chunks around the currently selected image, so that there is no delay waiting for a new chunk to be requested.