Disable Jpeg compression and panorama helper - Feature Requests - CHDK Forum

Disable Jpeg compression and panorama helper

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Disable Jpeg compression and panorama helper
« on: 21 / August / 2008, 07:26:04 »
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Is it possible to disable JPEG compression? Saving RAWs take too much time while JPEGs are many times overcompressed.

By panorama helper I mean the display one side of the previously taken picture. What I suggest is to be able to set which side of a picture is shown on LCD before shooting thus, it would help to create better pics for panorama.

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Offline LjL

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Re: Disable Jpeg compression and panorama helper
« Reply #1 on: 23 / August / 2008, 08:35:37 »
Uhm, but you can choose which side of the picture is shown, by hitting the left or right key in panorama mode before starting to shoot... or isn't that what you meant?

As for disabling JPEG compression, I suspect that's intrinsically impossible as JPEG is a lossy format by definition, unless you switch to noticeably different variants of JPEG such as Lossless JPEG or JPEG-LS.

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Offline dzsemx

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Re: Disable Jpeg compression and panorama helper
« Reply #2 on: 24 / August / 2008, 09:30:27 »
raw files are without compression :)
« Last Edit: 24 / August / 2008, 09:51:55 by dzsemx »

Re: Disable Jpeg compression and panorama helper
« Reply #3 on: 24 / August / 2008, 09:51:46 »
Is there a panorama mode for A460 (I have an A460)?

Yep, RAW is uncompressed but takes 3-4 times longer to save one picture.


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Offline dzsemx

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Re: Disable Jpeg compression and panorama helper
« Reply #4 on: 24 / August / 2008, 09:53:05 »
on other cameras with original firmware, takes even more, i don't think it's slow, with fast sd cards tskes less than 2 seconds
« Last Edit: 24 / August / 2008, 09:56:16 by dzsemx »

Re: Disable Jpeg compression and panorama helper
« Reply #5 on: 24 / August / 2008, 09:59:08 »
Then I should try sdhc :)

I just got up and mixed up things :)

Which are the fastest MICRO sd cards?
« Last Edit: 24 / August / 2008, 11:22:26 by vihar1 »

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Offline LjL

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Re: Disable Jpeg compression and panorama helper
« Reply #6 on: 24 / August / 2008, 10:20:50 »
SDHC doesn't make it faster, speed makes it faster. As for the panorama mode, I thought that was available throughout the A series. If not, emulating it may pose difficulties, due to the limited numbers of colors that can be used on the screen bitmap. Although I wonder... How does Canon's panorama mode do it? It must be using something other than the bitmap, something we currently don't access in CHDK.

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Offline dzsemx

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Re: Disable Jpeg compression and panorama helper
« Reply #7 on: 24 / August / 2008, 17:42:47 »
in panorama mode the fourth of the screen(2 times smaller height and width) is used for live preview and  previous shot can be copied to other portion of the screen, because it won't be overwritten
btw can we alter the screens YUV data? i newer tried :D bu i'll try it


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Offline LjL

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Re: Disable Jpeg compression and panorama helper
« Reply #8 on: 25 / August / 2008, 06:03:17 »
I've tried altering it, yes, but normally, it gets overwritten very fast by the data coming from the sensor, so that all you see is some unreadable flashing.

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Offline dzsemx

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Re: Disable Jpeg compression and panorama helper
« Reply #9 on: 25 / August / 2008, 12:06:58 »
and in review mode?

 

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