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Simon Waters wrote:
> Julian Hall wrote:
>>
>> Does GIMP have this functionality?
>
> GIMP has a batch mode, and can also have modules added (including Python).
>
>> Tedious to do it for every picture, but better than doing every step
>> manually.
>
> The netpbm tools are far better for bulk image manipulation.
>
> Of course you need some basic shell scripting skills, but it is so
> useful (and cool) to be able to resize, crop, and handle so many
> different image formats, so quickly.
>
> http://netpbm.sourceforge.net/doc/#prognotes
>
> The example above show, converting png to jpeg (why?), and how to
> brighten and image, but there are a lot of other programs in the suite.
>
>
> Say you have some "png" files and you want them all the same width as
> they'll all appear on the same web page template, and saved as "jpeg"
> files because the customer likes jpeg for some weird reason, but you
> don't want any compression artifacts introduced into the jpegs.
>
>
> So you start with a set of files....
>
> for afile in photodir/*.png
> do
> ....magic goes here...
> done
>
>
> The first step in the pipeline is usually to covert the image to pnm, so
> there are a load of programs names {imageformat}topnm.
>
> "pngtopnm $afile |"
>
> Then we want to make the resulting "pnm" the same width (say 200).
>
> "pnmscale -xsize=200 |"
>
> Then we want to convert to a jpeg, but preserve the quality.
>
> "pnmtojpeg -quality=100"
>
> And then save it to a file ">$afile.jpeg".
>
>
> Putting it together;
>
> for afile in photodir/*.png
> do
> pngtopnm $afile | pnmscale -xsize=200 | pnmtojpeg -quality=100 >$afile.jpeg
> done
>
> And you can use "mmv" to rename them if the ".png.jpeg" ending offends
> your sensibilities.
>
> It may seem a bit weird at first, but this is exactly how Unix/Linux was
> suppose to be used. Lots of small programs, that are efficient and do
> one task well, that hook together to produce a flexible system. If one
> step in the pipeline fails, it just skips that image.
>
> I use netpbm for thumbnails for product images for customer sites, and
> that sort of thing. But because the programs mostly have obvious names
> you can usually just type "pnm" (or type a graphic extension like
> "png"), and use the Bash shell tab auto-completion to find which program
> you need. Each program has a standard manual page, that explains its
> options.
>
> Here is a list of the programs in Debians netpbm package.....
>
> 411toppm anytopnm asciitopgm atktopbm bioradtopgm bmptopnm bmptoppm
> brushtopbm cmuwmtopbm eyuvtoppm fiascotopnm fitstopnm fstopgm g3topbm
> gemtopbm gemtopnm giftopnm gouldtoppm hipstopgm icontopbm ilbmtoppm
> imgtoppm jpegtopnm leaftoppm lispmtopgm macptopbm mdatopbm mgrtopbm
> mtvtoppm neotoppm palmtopnm pamcut pamdeinterlace pamdice pamfile pamoil
> pamstack pamstretch pamstretch-gen pbmclean pbmlife pbmmake pbmmask
> pbmpage pbmpscale pbmreduce pbmtext pbmtextps pbmto10x pbmtoascii
> pbmtoatk pbmtobbnbg pbmtocmuwm pbmtoepsi pbmtoepson pbmtog3 pbmtogem
> pbmtogo pbmtoicon pbmtolj pbmtomacp pbmtomda pbmtomgr pbmtonokia
> pbmtopgm pbmtopi3 pbmtoplot pbmtoppa pbmtopsg3 pbmtoptx pbmtowbmp
> pbmtox10bm pbmtoxbm pbmtoybm pbmtozinc pbmupc pcxtoppm pgmbentley
> pgmcrater pgmedge pgmenhance pgmhist pgmkernel pgmnoise pgmnorm pgmoil
> pgmramp pgmslice pgmtexture pgmtofs pgmtolispm pgmtopbm pgmtoppm
> pi1toppm pi3topbm pjtoppm pngtopnm pnmalias pnmarith pnmcat pnmcolormap
> pnmcomp pnmconvol pnmcrop pnmcut pnmdepth pnmenlarge pnmfile pnmflip
> pnmgamma pnmhisteq pnmhistmap pnmindex pnminterp pnminterp-gen pnminvert
> pnmmargin pnmmontage pnmnlfilt pnmnoraw pnmnorm pnmpad pnmpaste pnmpsnr
> pnmquant pnmremap pnmrotate pnmscale pnmscalefixed pnmshear pnmsmooth
> pnmsplit pnmtile pnmtoddif pnmtofiasco pnmtofits pnmtojpeg pnmtopalm
> pnmtoplainpnm pnmtopng pnmtops pnmtorast pnmtorle pnmtosgi pnmtosir
> pnmtotiff pnmtotiffcmyk pnmtoxwd ppm3d ppmbrighten ppmchange ppmcie
> ppmcolormask ppmcolors ppmdim ppmdist ppmdither ppmfade ppmflash
> ppmforge ppmhist ppmlabel ppmmake ppmmix ppmnorm ppmntsc ppmpat ppmquant
> ppmquantall ppmqvga ppmrainbow ppmrelief ppmshadow ppmshift ppmspread
> ppmtoacad ppmtobmp ppmtoeyuv ppmtogif ppmtoicr ppmtoilbm ppmtojpeg
> ppmtoleaf ppmtolj ppmtomap ppmtomitsu ppmtompeg ppmtoneo ppmtopcx
> ppmtopgm ppmtopi1 ppmtopict ppmtopj ppmtopuzz ppmtorgb3 ppmtosixel
> ppmtotga ppmtouil ppmtowinicon ppmtoxpm ppmtoyuv ppmtoyuvsplit ppmtv
> psidtopgm pstopnm qrttoppm rasttopnm rawtopgm rawtoppm rgb3toppm
> rletopnm sbigtopgm sgitopnm sirtopnm sldtoppm spctoppm sputoppm st4topgm
> tgatoppm thinkjettopbm tifftopnm wbmptopbm winicontoppm xbmtopbm
> ximtoppm xpmtoppm xvminitoppm xwdtopnm ybmtopbm yuvsplittoppm yuvtoppm
> zeisstopnm
>
> I'm told you can usually ignore (pbm, pgm, ppm) as they are hidden
> behind the "pnm" commands most of the time. Certainly I get everything I
> need done with "pnm" commands.
>
> The pnm ones....... you can just guess what half of them do.
>
> anytopnm bmptopnm fiascotopnm fitstopnm gemtopnm giftopnm jpegtopnm
> palmtopnm pngtopnm pnmalias pnmarith pnmcat pnmcolormap pnmcomp
> pnmconvol pnmcrop pnmcut pnmdepth pnmenlarge pnmfile pnmflip pnmgamma
> pnmhisteq pnmhistmap pnmindex pnminterp pnminterp-gen pnminvert
> pnmmargin pnmmontage pnmnlfilt pnmnoraw pnmnorm pnmpad pnmpaste pnmpsnr
> pnmquant pnmremap pnmrotate pnmscale pnmscalefixed pnmshear pnmsmooth
> pnmsplit pnmtile pnmtoddif pnmtofiasco pnmtofits pnmtojpeg pnmtopalm
> pnmtoplainpnm pnmtopng pnmtops pnmtorast pnmtorle pnmtosgi pnmtosir
> pnmtotiff pnmtotiffcmyk pnmtoxwd pstopnm rasttopnm rletopnm sgitopnm
> sirtopnm tifftopnm xwdtopnm zeisstopnm
>
> Now why would I want to do this in something like the GIMP, often I'm
> done before the GIMP would finish loading? Although a "previewing file
> managers" which show a thumbnail view of every image in a directory is a
> great help here, as you can spot when you mess up quickly.
>
> Anyone fancy a play -- try writing a script that makes outline/sketch
> like versions of a directory of images, all at the same small size,
> using png, and then looks around for a tool that ensures all the png
> files are as small as possible. pnmconvol can be used as a kind of
> Gaussian filter to do this. The ambitious can then add borders to them,
> and mount them in montages. It should be much more than the example given.
AMAZING. Why was there so much enthusiasm about imagemagick when we have
this!?!?
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