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turks
Beginner
104 Views

JPEG2000 Ratio not working in Picnic App ?

I'm using the picnic app to open an 80MB RGB BMP file. When saving as LOSSY jp2, I'm seeing a 16MB
jp2 file using "No MCT" and an 8MB using "MCT" at EVERY ratio value. The ratio slider does not seem to change
file size at all using "MCT". If using "NoMCT" then the 16MB size goes to 8MB ONLY if the ratio value is zero.

In summary, if using "NoMCT" then file size remains the same (16MB) for ratio values >0. Goes to 8MB when zero. My WT is set to WT53.

(If using WT97 then ratio does not change file size at all, regardless of MCT)
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7 Replies
Vladimir_Dudnik
Employee
104 Views

Could you please provide image you try to test on somehow?

Regards,
Vladimir
turks
Beginner
104 Views

Quoting - turks
I'm using the picnic app to open an 80MB RGB BMP file. When saving as LOSSY jp2, I'm seeing a 16MB
jp2 file using "No MCT" and an 8MB using "MCT" at EVERY ratio value. The ratio slider does not seem to change
file size at all using "MCT". If using "NoMCT" then the 16MB size goes to 8MB ONLY if the ratio value is zero.

In summary, if using "NoMCT" then file size remains the same (16MB) for ratio values >0. Goes to 8MB when zero. My WT is set to WT53.

(If using WT97 then ratio does not change file size at all, regardless of MCT)
Here's the 80MB BMP file I am using for testing.

Thanks !
turks
Beginner
104 Views

Could you please provide image you try to test on somehow?

Regards,
Vladimir
Here's the 80MB BMP file I am using for testing.

Thanks !
Vladimir_Dudnik
Employee
104 Views

I've just tested your file with picnic:

wt97 is on
mct is on

ratio 1 - result JP2 file size is ~800 Kb
ratio 2 - result JP2 file size is ~1.6 Mb
ratio 4 - result JP2 file size is ~3.2 Mb
ratio10 - result JP2 file size is ~8.2 Mb

Regards,
Vladimir
turks
Beginner
104 Views

I've just tested your file with picnic:

wt97 is on
mct is on

ratio 1 - result JP2 file size is ~800 Kb
ratio 2 - result JP2 file size is ~1.6 Mb
ratio 4 - result JP2 file size is ~3.2 Mb
ratio10 - result JP2 file size is ~8.2 Mb

Regards,
Vladimir
Hi Vladimir,

Thanks for that. I was trying ratios of like 30, 50, 80 and 100 and did not see any change. Is the ratio range 0-100
or 0-10 ? I just did the test with 1,2,4,10 and got the same results as you. Why was my file size static at these higher ratios ?

Thanks again.
Mikhail_Kulikov__Int
New Contributor I
104 Views

Hi,

the slider represents 1-100% of file size for lossy as approximately highest limit of file size. (Or 0% -for lossless wt53 or approximately lossless for wt97).

Note, if you compress this file LOSSLESS with MCT the file size is ~8.9 Mb. (Because it's practicaly equally white that means a lot of similar info can be skipped.)

So for lossy we have the real file size changing in the range 1-10% , no practical reason to keep more than 10% of original size, because no any improvement in quality can be achived, it's already lossless(for wt53, or approximately lossless for wt97), which is the best possible quality.


Regards,
Mikhail
turks
Beginner
104 Views

Quoting - mkulikov
Hi,

the slider represents 1-100% of file size for lossy as approximately highest limit of file size. (Or 0% -for lossless wt53 or approximately lossless for wt97).

Note, if you compress this file LOSSLESS with MCT the file size is ~8.9 Mb. (Because it's practicaly equally white that means a lot of similar info can be skipped.)

So for lossy we have the real file size changing in the range 1-10% , no practical reason to keep more than 10% of original size, because no any improvement in quality can be achived, it's already lossless(for wt53, or approximately lossless for wt97), which is the best possible quality.


Regards,
Mikhail
Thanks Mikhail for the explanation !
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