In general, when I try to zoom a DjVu image, Okular shows only a white background instead continuing zooming the image. The zoom level is distinct in each DjVu document. You can download this DjVu image http://www.tr3s60.com/Reproduccion_Ampliada/Zaragoza_1861_djvu/AMZ_4-2_0274.djvu and enlarge it in Okular till you reach 50% level. Then you will see a white background, not the image. Reproducible: Always Steps to Reproduce: 1.Open a DjVu image 2.Zoom in it till you see no image Actual Results: Okular is showing a white background instead of the image. Expected Results: To continue enlarging the image. For researchers, this is an important feature, cause they need to see fine details in old documents digitized in DjVu. DjVuLibre (DjView) enlarge the referenced document as far as 1200% level.
The problem is that we don't support tiled rendering for djvu files, i.e. we always render the whole page, and that means that we pass the "safety limit" net of size for a single page when zooming too much. I'll increase the safety limits since they are quite small for nowadays standards and that will allow for some more zooming but the real fix is supporting the tiled rendering like we do for pdf files.
I understand, so I'll be waiting for the size limit change. But, what's the problem about implementing tile rendering on DjVu files? Is about complexity of the format? Is not usefull the open source code of DjView to embed that functionallity in Okular? Thank you
It's not hard, just need someone with time to do it.
Ok, I'm sure it will be a great improvement for Okular users that will not need to install DjView in the future. ;)
Thank you for the bug report. As this report hasn't seen any changes in 5 years or more, we ask if you can please confirm that the issue still persists. If this bug is no longer persisting or relevant please change the status to resolved.
Issue still persist, despite it appears now from 151% https://www.zaragoza.es/imagenes_archivo/cartografia/AMZ_4-2_0274/AMZ_4-2_0274.djvu