JPEG Lossless Join

[Lite]

Hello
In many internet pages large JPEG pictures are divided into many small ones. So, they have the same compression settings. Therefore, theoretically it is possible to combine them into one big without recompress, ie without any loss of data.

Can you implement such a possibility in the XnView?

At the moment there is no program that can do that. There is only a one good program which does it with recompress. It's called JPEG Joiner. Web page is: http://downloads.mcrenox.com.ar/
Link to download: http://www.mcrenox.com.ar/downloads/jpegjoiner.exe

Its graphical interface is quite easy and well thought out. Therefore, it might serve as a GUI model for such functionality in XnView.

[oops66]

Hello,
I support ++ this kind of functionalities (in fact it's a other kind of image format which should be supported by XnView among the others 400 graphics formats)
here: http://www.xnview.com/en/formats.html

[XnTriq]

I support this request. (For now I'm using Jpegjoin.)

[Lite]

JPEG Wizard (shareware) is also able to combine JPEG as Jpeg Join. But both of these programs have one significant limitation - if the dimensions of parts are not multiples of 4 (8), then combine will not work right, because of need to add extra pixels, or lay on top of the current part the next part and losing the pixels on current part that go beyond multiplicity 4 (8).

There needed more clever approach to restructure the image without these restrictions.

[DOS386]

In many internet pages large JPEG pictures are divided into many small ones. So, they have the same compression settings. Therefore, theoretically it is possible to combine them into one big without recompress, ie without any loss of data.

YES, but only if size is multiple of 8 or 16 ...

JPEG Wizard (shareware) is also able to combine JPEG as Jpeg Join. But both of these programs have one significant limitation - if the dimensions of parts are not multiples of 4 (8), then combine will not work right, because of need to add extra pixels, or lay on top of the current part the next part and losing the pixels on current part that go beyond multiplicity 4 (8).

Are yout sure it's 4 (8) and not 8 or 16 ?

There needed more clever approach to restructure the image without these restrictions

I am more skeptic about some no-go's like this one ...

OTOH, I support the idea to add more lossless JPG features into the Lib + XN + NC (whenever size divisibility allows to do):

- join
- crop (more than the "auto-crop" when mirroring or rotating by 90 deg)
- blurring some blocks (leaving the other lossless)
- replacing some blocks by an incoming BMP (will cause some loss on those blocks)