Browse code
Add jpgscancropmargin.pike
Dario Rodriguez authored on 28/12/2020 19:10:54
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+#!/usr/bin/pike |
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+/* |
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+ * cropzoomer.pike |
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+ * |
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+ * Utility to zoom a little on scanned pages (req. RGB page) |
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+ * |
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+ * Author: Dario Rodriguez dario@softhome.net |
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+ * The program is licensed under the terms of the MIT/X license. |
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+ */ |
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+ |
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+int bgthreshold=64; // from 0 to 255 |
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+int amplitude=15; // from 1 to 255 |
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+ |
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+int darkenfactor=2; // from 1 to 255 |
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+ |
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+int |
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+main(int argc, array(string) argv) |
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+{
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+ Image.Image in,out,inhsv,indistance; |
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+ string infile,outfile; |
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+ if(argc!=3 || argv[argc-1]=="--help") {
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+ write("Syntax: "+argv[0]+" infile.jpg outfile.png\n");
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+ return(1); |
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+ } |
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+ write(argv[1]+" -> "+argv[2]+"\n"); |
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+ write("* Generating intermediate representations...");
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+ infile=argv[1]; |
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+ outfile=argv[2]; |
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+ in=Image.load(infile); |
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+ inhsv=in->copy()->rgb_to_hsv(); |
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+ indistance=in->copy()->distancesq(255,255,255); |
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+ out=Image.Image(in.xsize(),in.ysize()); |
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+ // Guess the most used bg color |
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+ write("done.\n* Guessing most used bg hue...");
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+ array(int) hues=allocate(256); |
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+ int x,y; |
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+ int h,n,selh,seln,j; |
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+ int c; |
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+ for(y=0;y<in.ysize();y++) {
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+ for(x=0;x<in.xsize();x++) {
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+ c=indistance.getpixel(x,y)[0]; |
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+ if(c<bgthreshold) {
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+ // possible bg |
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+ c=inhsv.getpixel(x,y)[0]; |
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+ hues[c]++; |
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+ } |
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+ } |
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+ if(!(y%1000)) |
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+ write(".");
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+ } |
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+ for(selh=0,seln=0,h=0;h<256;h++) {
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+ for(n=0,j=-amplitude;j<amplitude;j++) {
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+ n+=hues[(h+256+j)%256]; |
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+ } |
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+ if(n>seln) {
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+ seln=n; |
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+ selh=h; |
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+ } |
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+ } |
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+ write(""+selh);
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+ // Getting image statistics |
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+ write(".\n* Getting image statistics...");
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+ int d; |
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+ array(int) ycoverage=allocate(in.ysize()); |
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+ for(y=0;y<in.ysize();y++) |
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+ ycoverage[y]=0; |
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+ array(int) xcoverage=allocate(in.xsize()); |
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+ for(x=0;x<in.xsize();x++) |
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+ xcoverage[x]=0; |
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+ for(y=0;y<in.ysize();y++) {
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+ for(x=0;x<in.xsize();x++) {
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+ c=indistance.getpixel(x,y)[0]; |
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+ h=inhsv.getpixel(x,y)[0]; |
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+ // calc. hue distance to bg hue wrapping on the color wheel |
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+ if(h<selh) {
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+ if((selh-h)<(h+256-selh)) |
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+ d=selh-h; |
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+ else |
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+ d=h+256-selh; |
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+ } else {
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+ if((h-selh)<(selh+256-h)) |
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+ d=h-selh; |
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+ else |
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+ d=selh+256-h; |
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+ } |
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+ // heuristics |
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+ if(!(c<bgthreshold && d<bgthreshold)) {
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+ ycoverage[y]++; |
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+ xcoverage[x]++; |
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+ } |
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+ } |
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+ if(!(y%1000)) |
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+ write(".");
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+ } |
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+ // Looking for largest white zone |
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+ write(".\n* Looking for white zone from the center...");
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+ // average numbers to a 40th of the length |
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+ int pos; |
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+ int i; |
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+ int yblock=(int) in.ysize()/40; |
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+ int xblock=(int) in.xsize()/40; |
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+ if(yblock>=2) {
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+ array(int) last=allocate(yblock); |
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+ for(pos=0;pos<yblock;pos++) |
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+ last[pos]=ycoverage[pos]; |
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+ for(y=0,pos=0;y<in.ysize();y++,pos++,pos%=yblock) {
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+ last[pos]=ycoverage[y]; |
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+ for(c=0,i=0;i<yblock;i++) |
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+ c+=last[i]; |
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+ ycoverage[y]=(int) (c/yblock); |
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+ } |
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+ } |
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+ if(xblock>=2) {
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+ array(int) last=allocate(xblock); |
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+ for(pos=0;pos<xblock;pos++) |
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+ last[pos]=xcoverage[pos]; |
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+ for(x=0,pos=0;x<in.xsize();x++,pos++,pos%=xblock) {
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+ last[pos]=xcoverage[x]; |
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+ for(c=0,i=0;i<xblock;i++) |
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+ c+=last[i]; |
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+ xcoverage[x]=(int) (c/xblock); |
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+ } |
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+ } |
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+ // get ymin/ymax and xmin/xmax |
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+ int ymax=0,ymin=in.xsize(); |
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+ for(y=0;y<sizeof(ycoverage);y++) {
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+ if(ycoverage[y]<ymin) |
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+ ymin=ycoverage[y]; |
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+ if(ycoverage[y]>ymax) |
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+ ymax=ycoverage[y]; |
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+ } |
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+ int xmax=0,xmin=in.xsize(); |
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+ for(x=0;x<sizeof(xcoverage);x++) {
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+ if(xcoverage[x]<xmin) |
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+ xmin=xcoverage[x]; |
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+ if(xcoverage[x]>xmax) |
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+ xmax=xcoverage[x]; |
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+ } |
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+ int xdiff=(xmax-xmin); |
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+ int ydiff=(ymax-ymin); |
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+ int xminthreshold=xmin+xdiff/50; |
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+ int yminthreshold=ymin+ydiff/50; |
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+ // look for first dip under yminthreshold |
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+ int y0,y1,x0,x1; |
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+ for(y=in.ysize()/4;y>0;y--) {
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+ if(ycoverage[y]<yminthreshold) |
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+ break; |
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+ } |
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+ y0=y-2*yblock; |
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+ y0=(y0<0)?0:y0; |
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+ for(y=in.ysize()*3/4;y<(in.ysize()-1);y++) {
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+ if(ycoverage[y]<yminthreshold) |
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+ break; |
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+ } |
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+ y1=y+2*yblock; |
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+ y1=(y1>=in.ysize())?(in.ysize()-1):y1; |
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+ // look for first dip under xminthreshold |
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+ for(x=in.xsize()/4;x>0;x--) {
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+ if(xcoverage[x]<xminthreshold) |
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+ break; |
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+ } |
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+ x0=x-2*xblock; |
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+ x0=(x0<0)?0:x0; |
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+ for(x=in.xsize()*3/4;x<(in.xsize()-1);x++) {
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+ if(xcoverage[x]<xminthreshold) |
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+ break; |
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+ } |
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+ x1=x+2*xblock; |
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+ x1=(x1>=in.xsize())?(in.xsize()-1):x1; |
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+ // Crop |
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+ write(".\n* Cropping from "+out.xsize()+"x"+out.ysize()+" rectangle ("+x0+","+y0+")-("+x1+","+y1+")...");
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+ out=in->copy(x0,y0,x1,y1,255,255,255); |
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+ // Write result |
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+ write("done.\n* Writing result to disk...");
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+ Stdio.write_file(outfile,Image.PNG.encode(out)); |
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+ write("done.\n* Process finished.\n");
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+} |