Re: [Texmacs-dev] eps image is pixelated

[Michael Lachmann]

On 14 August 2013 10:49, Miguel de Benito Delgado <address@hidden> wrote:

Joris asked me to convert it to C++, and it stopped there.

You wrote it in scheme, I guess? Did you send the patch to savannah?

no, in bash.... it was called ps_to_eps, and looked like this:

---

#!/bin/bash

# 1 2 wh 3 4 wh 5 out 6 in

CRC=crc32

CACHE=~/.TeXmacs/system/cache/images

echo crc32 $6

CRC=`$CRC $6 | sed  's/\(.\)/\\1\//g'`

echo $CRC

mkdir -p $CACHE/$CRC

img=$CACHE/$CRC/img_$1x$2_$3x$4.png

EPSFILE=`mktemp -t ps_to_png_tmp.XXXX`

if ! [ -a $img ] ; then

    ps2epsi $6 $EPSFILE # This is only needed because at some point

    # There was a bug that didn't create correct eps files, and now

    # I have some .tm files with wrong ps in them.

    gs -dQUIET -dNOPAUSE -dBATCH -dSAFER -sDEVICE=png16m -dGraphicsAlphaBits=4 -dEPSCrop -g$1"x"$2 -r$3"x"$4 -sOutputFile=$img $EPSFILE

    rm $EPSFILE

fi

ln -s $img $5

--

Primitive, I know.... but it worked pretty well.

For sessions (like R...) filename+width+height won't be good... they are all the same dimensions, and probably have

similar names. I see that we have MD5 routines in dpxcrypt in Pdf. I could use that.

 

Should I restore that? (And if I add the CRC caching to the C++ source, where's the best place to put it?)

I guess you could start looking around in scalable_image and cached_load_picture.

sure, I'll look.

 

Would this CRC caching also cache scaled versions of the images? That is: would we still suffer the performance hit of conversion each time the canvas scrolls? If yes, could you add width+height to the index of the cache?

The scheme above caches all scales of images. One needs to think about when/how to clean the cache.

Michael