Re: Images in MultiMarkdown -> context -> PDF

[Guy Stalnaker <jstalnak@wisc.edu>]

In case anyone else has been following this thread, here is the shell 
script I wrote to resize an image width to 6.5x72dpi so they fit in the 
standard letter pagesize \textwidth with 1-inch margins and add image 
density/resolution information so that context correctly sizes them in 
the PDF output file.

<code>
#!/bin/bash
#set -x

TEXTWIDTH="438" #6.5inches x 72 dpi

for i in *.jpg ;
do
     SIZEX="$(exiftool -imagewidth $i | awk '{print $4}')"
     SIZEY="$(exiftool -imageheight $i | awk '{print $4}')"
     echo "Image $i is $SIZEX x $SIZEY, max X is $TEXTWIDTH ..."
     if [[ $SIZEX > $TEXTWIDTH ]] ; then
         convert $i -resize $TEXTWIDTH -density 72 $i
         echo "resized image $i from $SIZEX to $TEXTWIDTH."
     fi
done
</code>

Regards,

Guy

On 11/21/2012 02:36 PM, Sietse Brouwer wrote:
> Guy wrote:
>> Well, that lead to an interesting experiment. I used convert to -resample a
>> set of images to 300dpi and redid the compile. They are all now too bod,
>> many off the right side of the page. Then did the same but set to 72. They
>> are still too big. Odd, from too small to too big.
> I think you don't want -resample, but -density:
>
> # density given in dpi
> convert pic.jpg -density 72 pic-out.jpg
>
> convert -density keeps the pixel size and changes the display size by
> setting the density metadata.
> convert -resample keeps the display size and changes the pixel size by
> resampling at a certain density. (This explains why the picture
> remained the same too-large size when you resampled at 72 and 300
> dpi.)
>
> Because you want to change the display size (and also because
> resampling is a lossy process), I think you want -density.
>
> As for the density value you want to use:
> Your picture is 547px wide, so if you want it to display it 3 inches
> wide you should set its density metadata to 547/3 = 183 dpi.
>
> Does this work?
> All the best,
> Sietse

-- 

"There is only love, and then oblivion. Love is all we have
to set against hatred." (paraphrased) Ian McEwan

Guy Stalnaker, I^2@DOIT, 1210 West Dayton Street, Room 3209 CSS, Madison
WI 53719-1220, jstalnak@wisc.edu, work 608.263.8035, cell 608.235.4718,
fax 608.265.6681, page page-guy@watchdog.doit.wisc.edu

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