[mmjoshi]

I need to convert my K20D images to wallpapers for my Windows 7 Dell Vostro 13 notebook. I shoot in raw DNG format. I can convert to jpg with 1920:1200 resolution. But the image would not cover the complete screen. There are two wide patches on both sides of the image.

Has anyone successfully converted K20D or any Pentax raw image in the DNG formmat to wallpapers?

mj

[eccs19]

I do it regularly. You need to find out what your screen resolution is set to, and crop to that size, then it will be a perfect fit. You do need to convert them to JPG.

On my HP, I just right click on the desktop, and select Resolution. There is tells me that my screen resolution is set to 1366x768, so I then just crop my picture to that size.

[Wheatfield]

I need to convert my K20D images to wallpapers for my Windows 7 Dell Vostro 13 notebook. I shoot in raw DNG format. I can convert to jpg with 1920:1200 resolution. But the image would not cover the complete screen. There are two wide patches on both sides of the image.

Has anyone successfully converted K20D or any Pentax raw image in the DNG formmat to wallpapers?

mj

Yes, I do it all the time. As the obove poster says, crop to your screen resolution. As an alternative, set your wallpaper to stretch, though this can give odd results.

[mmjoshi]

Yes, I do it all the time. As the obove poster says, crop to your screen resolution. As an alternative, set your wallpaper to stretch, though this can give odd results.

Thanks for the replies. I tried your procedure in IrfanView. My screen resolution is 1366x768. I resized the dng images to this resolution and converted them to jpg format. However, if I preserve the aspect ratio, then the converted image is still smaller than the screen size. If I do not preserve the aspect ratio the image fits the screen but I think the images look stretched in the horizontal direction as compared to the original one.

Am I doing something wrong?

mj

[Wheatfield]

You can't just resize unless you are willing to put up with a bit of wonkiness in the image.
You have to physically crop the picture using a crop tool which Irfanview seems to lack.

[mmjoshi]

You can't just resize unless you are willing to put up with a bit of wonkiness in the image.
You have to physically crop the picture using a crop tool which Irfanview seems to lack.

Hi Wheatfield

I also have Gimp and Xnview but have not used them extensively. Will any of them be able to do what you are suggesting? Else let me know which tool you use, preferably freeware/opensource and how this tool can be used.

mj

[Wheatfield]

I suspect gimp can crop, but I use Photoshop for this sort of stuff so i can't speak to the software you are using.
Sorry.

[dosdan]

1366x768

That's an Aspect Ratio of 1.78. APS-C DSLR AR is 1.5. So you are going to have to crop a bit off the top and/or bottom of the photo to make it suitable for the PC's wallpaper. XnView can do this:

1. Start with the full-sized image.
2. Use Edit | Set Selection Ratio. Choose 16:9 (1.78).
3. Then click & drag across the image to set the AR-constrained cropping area and then click on the Crop icon (or use the Ctrl-Y hotkey) to complete the crop.
4. Then resize the 16:9 image to 1366 x 768 using Image | Resize (or the Shift-S hotkey).

Dan.

[iTod]

Faststone, IIRC, has a tool for this exact purpose.
I could be mistaken, though, as I've not used it for some time now. Switched to Linux & Mac...
Come to think of it, doesn't Picassa also have something similar?
Good luck!

[mmjoshi]

Thanks Wheatfield, dosdan and iTod. I could finally do what I wanted. XnView indeed can do this. But it has to be done individually for each file. FastStone on the other hand can do this in a batch mode, if you can accept the automatic cropping. Which was a blessing for me as I had to convert a number of images! The results from a wallpaper point of view are more than adequate. However, it does brighten the colors a bit. I haven't figured out how to prevent this!

mj

[Wheatfield]

However, it does brighten the colors a bit. I haven't figured out how to prevent this!

mj

Sounds like you are changing colour profiles during your processing. Make sure the end result is an sRGB file.

[dosdan]

T XnView indeed can do this. But it has to be done individually for each file. FastStone on the other hand can do this in a batch mode, if you can accept the automatic cropping.

XnView can so this in batch processing mode too (Ctrl-U). You can stack up Canvas Resize followed by Resize to do an indiscriminate crop to a different AR & then resize it to 1366x768 in one batch job. You can save the sequence of commands and reload them when needed.

Dan

[mmjoshi]

XnView can so this in batch processing mode too (Ctrl-U). You can stack up Canvas Resize followed by Resize to do an indiscriminate crop to a different AR & then resize it to 1366x768 in one batch job. You can save the sequence of commands and reload them when needed.

Dan

Dan

Sorry about being a little thick here. I tried to follow your instructions but could not manage the final 1366x768 size. Do I need to do the Resize twice? And where do I give the 1366x768 parameters?

Apologies if I am asking elementary questions.

mj

[dosdan]

Dan

Sorry about being a little thick here. I tried to follow your instructions but could not manage the final 1366x768 size. Do I need to do the Resize twice? And where do I give the 1366x768 parameters?

Two commands in the batch list:

1. Resize Canvas. Width = 100% Height = 84%. The height percentage is derived from 1.5 (original APS-C AR) / 1.78 (new PC AR). Centre the resize/crop. Make sure you do a percentage resize - don't specify the W & H in pixels. This is effectively a full-width crop with an AR of 1.78.

To explain this consider an original file with the dimensions of 3000px width & 2000px height. That's a 1.5 AR. With a canvas width of 100%, new width is 3000px. 84% of 2000px height = 1680px. New AR = 3000/1680 = 1.79 (slight rounding error because we can't use decimal places in the percentage figures).

2. Resize. Width = 1366 Height = 768.


Also you can automatically create a sub-directory (if it doesn't already exist) off the directory where the selected photos reside, by specifying $\Cropped for Wallpaper as the output directory in your batch job file. So if the photos are in C:\Photos, the cropped versions will be in C:\Photos\Cropped For Wallpaper.

Dan.