Gimp Background scaling/centering
Posted: Sun Jul 25, 2010 8:23 pm
Thought I'd share another script.
This one is for gimp- it will load an image, center & scale it, and then save it out to \"background.jpg\" in your working directory. Yes, beware that it automatically over-writes that file if you happen to have one in the directory in that name. Save the following code to a file, and dump it in your ~/.gimp-2.6/scripts/ folder (or windows equivalent). It scales down, but never up, and preserves the original file's aspect ratio, adding bars of a selected solid color - default black.
Also, if you've got linux, and want to have a random file picked for you & sent through the filter, you may use this: Note that you need to pass the desired search directory to the script, and that you can optionally over-ride the random part of it with a second parameter containing the desired filename. You will want to tweak the code to match your screen resolution. Also note that it writes to a \"background.jpg\" file in the search directory, so be careful about it replacing some image that's near and dear to you.
This one is for gimp- it will load an image, center & scale it, and then save it out to \"background.jpg\" in your working directory. Yes, beware that it automatically over-writes that file if you happen to have one in the directory in that name. Save the following code to a file, and dump it in your ~/.gimp-2.6/scripts/ folder (or windows equivalent). It scales down, but never up, and preserves the original file's aspect ratio, adding bars of a selected solid color - default black.
Code: Select all
; Background-resize
; Simplified scaling routine. Loads & scales an image, if needed.
(define (background-scale sourceImg
red
green
blue
width
height
)
(let*
(
;Declare some values used along the way
(widthOffset 0)
(heightOffset 0)
(scaleFactor 1)
(finalLayer)
(background (list red green blue))
;Create a new Image
(theImage (car
(gimp-image-new
width
height
RGB
)
)
)
(theLayer (car
(gimp-layer-new
theImage
width
height
RGB-IMAGE
\"theLayer\"
100
NORMAL
)
)
)
;Load the source image
(sourceImageLayer (car
(gimp-file-load-layer
0
theImage
sourceImg
)
)
)
;Read the size of the source image
(sourceWidth (car
(gimp-drawable-width
sourceImageLayer
)
)
)
(sourceHeight (car
(gimp-drawable-height
sourceImageLayer
)
)
)
;At this point we're done initializing things
)
;Create a background layer, and fill it with the selected color.
(gimp-image-add-layer theImage theLayer 0)
(gimp-context-set-background background)
(gimp-drawable-fill theLayer BACKGROUND-FILL)
;Insert the source image
(gimp-image-add-layer
theImage
sourceImageLayer
0
)
;Figure necessary resizing & offsetting for Monitor
;Find the desired scale factor (source will be multiplied by this)
;The image will be scaled down to fit, but never up, the image is scaled to fit in both height in width.
(if (> sourceHeight height)
(set! scaleFactor (/ height sourceHeight)
)
)
(if (> sourceWidth width)
(if (> scaleFactor
(/ width sourceWidth)
)
(set! scalefactor (/ width sourceWidth)
)
)
)
;scale the image, if scaling is needed
(if (> 1 scaleFactor)
(gimp-layer-scale-full
sourceImageLayer
(* sourceWidth scaleFactor)
(* sourceHeight scaleFactor)
TRUE
2
)
)
;figure the needed offset to center it on the monitor
(set! widthOffset (/
(- width
(* sourceWidth scaleFactor)
)
2)
)
(set! heightOffset (/
(- height
(* sourceHeight scaleFactor)
)
2)
)
;offset the image
(gimp-layer-set-offsets
sourceImageLayer
widthOffset
heightOffset
)
;merge the layers
(gimp-image-flatten theImage)
;get the ID of the layer
(set! finalLayer (car (gimp-image-get-active-layer theImage)))
; Not needed for batched usage
; (gimp-display-new theImage)
(file-jpeg-save
1
theImage
finalLayer
\"background.jpg\"
\"background.jpg\"
.85
0
1
1
\"GIMP-generated background file\"
1
1
0
2
)
)
)
(script-fu-register \"background-scale\"
\"Background-scale\"
\"will scale and center a source image, so it looks proper on your screen\"
\"D3snoopy\"
\"D3snoopy\"
\"2009\"
\"RGB\"
SF-FILENAME \"Source Image\" \"File\"
SF-VALUE \"Background Color- Red\" \"0\"
SF-VALUE \"Background Color- Green\" \"0\"
SF-VALUE \"Background Color- Blue\" \"0\"
SF-VALUE \"Screen Width\" \"1680\"
SF-VALUE \"Screen Height\" \"1050\"
)
(script-fu-menu-register \"background-scale\"
\"<Toolbox>/Filters/Background\")
Code: Select all
#!/bin/bash
# searches through a directory for .jpg background candidates, randomly picks one, and runs a gimp script to size & position it for background use.
# The output files is ~/background.jpg
DIR=\"$1\"
FILE=\"$2\"
RANDOM=`date '+%s'`
# find the number of files we're working with
cd $DIR
NUMBER=`ls -1 | grep .*.jpg | wc -l`
echo $NUMBER
RANDNUM=$[ ($RANDOM % $NUMBER) + 1]
echo $RANDNUM
# the random number selected represents the file number that we'd like to use.
# setting the file to be used. If a file parameter was sent, test for existence & using, otherwise using one based on the random number generated.
if test $FILE; then
if test -f $FILE; then
echo \"File defined, using $FILE\"
else
echo \"Invalid file, picking a random one\"
FILE=$(ls -1 | sed -n \"$RANDNUM p\")
fi
else
FILE=$(ls -1 | sed -n \"$RANDNUM p\")
echo \"Using $FILE\"
fi
echo \"Sending the file to gimp\"
echo \"Executing the following line\"
echo \"This file is sent to your home folder\"
#gimp -i -b '(scale-resize-background \"'$FILE'\" 0 0 0 1680 1050 1920 1080 0)' -b '(gimp-quit 0)'
gimp -i -b '(background-scale \"'$FILE'\" 0 0 0 1680 1050)' -b '(gimp-quit 0)'
mv \"background.jpg\" ~/
# poke the xfce desktop to update the image displayed
xfdesktop --reload
Although it's worth pointing out that the scheme convention is to separate-words-with-hyphens as opposed to separatingWordsWithCamelCase, especially since not all dialects are case-sensitive.