Bad quality when downsizing image (posterization)
I am experiencing a strange problem when exporting a downsized jpg with a process recipe. Quality is ok when not resized below a certain threshold pixel size. At 25% or less (1500 pixel) posterization artefacts appear in the image, independent of the jpg quality slider or the color profile. This can already be seen in the proof view in C1, before exporting. The screenshots show the change from 1505 to 1500 pixels. Look at the gradient in the sky. Downsizing the same image with PS works fine. The original file was a RAF from Fuji XT-3, using the latest 20.02 C1 for Fujifilm version.
Did anyone encounter a similar problem? Any idea to circumvent this, other than using a different software?
Thanks Marco
Screenshots and the resulting two images can be seen here: https://www.dropbox.com/sh/2ea2jqv4ofuygia/AAD47TlRbOXjXPf4d3k8E3Dwa?dl=0
Did anyone encounter a similar problem? Any idea to circumvent this, other than using a different software?
Thanks Marco
Screenshots and the resulting two images can be seen here: https://www.dropbox.com/sh/2ea2jqv4ofuygia/AAD47TlRbOXjXPf4d3k8E3Dwa?dl=0
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It is possible to embed images in the post using the Img button but they do have to be downsized a lot (660 pixle wide)to fit the board window. That said I looked at your images and they all looked alright to me. That does not mean they are, downsizing is notorious for introducing artefacts unless the correct algorithm is used.
Just by chance I had CO open at the same time as viewing your post and it just happened to be showing some Irish Graveyard pictures I took in May 2016. I think this is the cross in your picture taken from the opposite direction
https://bglkcq.ch.files.1drv.com/y4mPe94sK8SCoMvLG_vzQ9UhXNqrqkArHE5XiAvMo5BGk896CdA50uk46Vx0r46MP6IEkTMj0BJvAj_8U_X4Zrx2C7bJ1pFWwuSiSngnBV7iL34f1xfS2YC0Wmf_Khy0o8MGUw05WlGdgoPA3jE0gaG_d4nlbJFUXjjurAcYXSViBxvIAPkEFvOhKGfsDppKGiivQRXabi9kH8cfSrV_kWZZw?width=660&height=440&cropmode=none0 -
Hi David, you are spot on. It is Corcomroe Abbey, not far from Galway, Ireland.
For me the degradation when downsizing to web size is unacceptable. I have created another image to illustrate the posterization in the sky. The only difference between left and right is that on the left side the image is downscaled to 1500 pixel and on the right side it is downscaled to 1505 pixel, which is good quality.
https://www.dropbox.com/s/vnfhwz5g1rr5e7p/CO-Error.jpg?raw=10 -
I don't have Fuji files, but 2 thouhgts came to my mind
1. can you try to restart C1 and try again? Or even the computer?
2. go to Edit / preferences and disable OPENCL ( set to "never") to see if the graphics card hardware acceleration has to do something with it. (In case hardware acceleration is currently ON)
Regards0 -
NNN636795052773784921 wrote:
Hi David, you are spot on. It is Corcomroe Abbey, not far from Galway, Ireland.
For me the degradation when downsizing to web size is unacceptable. I have created another image to illustrate the posterization in the sky. The only difference between left and right is that on the left side the image is downscaled to 1500 pixel and on the right side it is downscaled to 1505 pixel, which is good quality.
https://www.dropbox.com/s/vnfhwz5g1rr5e7p/CO-Error.jpg?raw=1
The artefacts are quite clear and distinct in this pair of pictures. I have seen that type of mottling before and am racking my brain to remember where and the cause. If I remember I will add another reply.
Dave0 -
@BeO: I restarted everything and disabled OpenCL, no change. Thanks anyway for the hint. 0
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