option --nn for PNG nearest neighbour

README.md

@@ -163,6 +163,8 @@ optional arguments:
                         specified hres or vres or --res=100 [default: off]
   -m, --mute            operate silently [default: informative]
   -n, --enlarge         enlarge smaller images [default: off]
+  --nn                  use nearest neighbour interpolation for PNG images
+                        [default: antialias]
   -p, --optimize        optimize the output images [default: off]
   -q N, --quality N     quality factor (N=1-95, JPEG only) [default: 75]
   -r, --recurse         process directories recursively [default: off]

auto-completion/bash/imgp-completion.bash

@@ -21,6 +21,7 @@ _imgp () {
         -k --keep
         -m --mute
         -n --enlarge
+        --nn
         -o --rotate
         -p --optimize
         -q --quality

auto-completion/fish/imgp.fish

@@ -14,6 +14,7 @@ complete -c imgp -s i -l includeimgp --description 're-process _IMGP files'
 complete -c imgp -s k -l keep        --description 'skip images with matching hres or vres'
 complete -c imgp -s m -l mute        --description 'operate silently'
 complete -c imgp -s n -l enlarge     --description 'enlarge smaller images'
+complete -c imgp      -l nn          --description 'use nearest neighbour interpolation for PNG'
 complete -c imgp -s o -l rotate   -r --description 'rotate clockwise by angle (in degrees)'
 complete -c imgp -s p -l optimize    --description 'optimize the output images'
 complete -c imgp -s q -l quality  -r --description 'specify quality factor (1-95)'

auto-completion/zsh/_imgp

@@ -19,6 +19,7 @@ args=(
     '(-k --keep)'{-k,--keep}'[skip images with matching hres or vres]'
     '(-m --mute)'{-m,--mute}'[operate silently]'
     '(-n --enlarge)'{-n,--enlarge}'[enlarge smaller images]'
+    '(--nn)--n[use nearest neighbour interpolation for PNG]'
     '(-o --rotate)'{-o,--rotate}'[rotate clockwise by angle]:degree'
     '(-p --optimize)'{-p,--optimize}'[optimize the output images]'
     '(-q --quiet)'{-q,--quality}'[specify quality factor (1-95)]:factor'

imgp

@@ -47,7 +47,7 @@ overwrite = False  # remove source images
 debug = False  # enable debug information
 no_res_opt = False  # --res is not specified
 pad = '_IMGP'  # output file suffix when --overwrite is unused
-nn_png = False # if the image is a png, use nearest neighbour interpolation
+png_ip = PIL.Image.ANTIALIAS  # default interpolation for PNG
 fill_color = '#ffffff'  # BG color to strip alpha channel
 init_time = time.time()  # profile the total time taken
 _VERSION_ = '2.4.1'  # current program version
@@ -231,7 +231,7 @@ def resize_image(src):
     vres = img.size[1]
     ImageFile.MAXBLOCK = hres * vres
 
-    antialias = PIL.Image.NEAREST if nn_png and _format == 'PNG' else PIL.Image.ANTIALIAS
+    antialias = png_ip if _format == 'PNG' else PIL.Image.ANTIALIAS
     if keep and (HRES == hres or VRES == vres or scale == 100):
         if not (_format == 'PNG' and convert):
             return
@@ -466,8 +466,8 @@ def parse_args(args=None, namespace=None):
            help='operate silently [default: informative]')
     addarg('-n', '--enlarge', action='store_true',
            help='enlarge smaller images [default: off]')
-    addarg('-nn', action='store_true',
-           help='use nearest neighbour interpolation for PNG images [default: off]')
+    addarg('--nn', action='store_true',
+           help='use nearest neighbour interpolation for PNG images [default: antialias]')
     addarg('-p', '--optimize', action='store_true',
            help='optimize the output images [default: off]')
     addarg('-q', '--quality', type=int, metavar='N', choices=range(1, 96),
@@ -494,7 +494,7 @@ def parse_args(args=None, namespace=None):
 
 def main():
     global HRES, VRES, scale, rotate, adapt, convert, dot, eraseexif, force, includeimgp, keep, enlarge, \
-           optimal, mute, recurse, size, qual, overwrite, debug, no_res_opt, pool, init_time, count, nn_png
+           optimal, mute, recurse, size, qual, overwrite, debug, no_res_opt, pool, init_time, count, png_ip
 
     args = parse_args()
 
@@ -554,7 +554,8 @@ def main():
         qual = args.quality
     overwrite = args.overwrite
     debug = args.debug
-    nn_png = args.nearest_neighbour
+    if args.nn:
+        png_ip = PIL.Image.NEAREST
 
     pool = Pool()
 

imgp.1

@@ -80,6 +80,9 @@ Do not process if image hres or vres matches specified hres or vres, or --res is
 .BI "-n, --enlarge"
 Enlarge smaller images. By default smaller images are not scaled if specified resolution is greater.
 .TP
+.BI "--nn"
+Use nearest neighbour interpolation for PNG images instead of default antialias.
+.TP
 .BI "-p, --optimize"
 Optimize output images using PIL library optimization algorithm. Disabled by default.
 .TP