Data commit

Task/Bitmap-Read-a-PPM-file/Phix/bitmap-read-a-ppm-file.phix

@@ -0,0 +1,32 @@
+-- demo\rosetta\Bitmap_read_ppm.exw (runnable version)
+
+function read_ppm(string filename)
+sequence image, line
+integer dimx, dimy, maxcolor
+atom fn = open(filename, "rb")
+    if fn<0 then
+        return -1 -- unable to open
+    end if
+    line = gets(fn)
+    if line!="P6\n" then
+        return -1 -- only ppm6 files are supported
+    end if
+    line = gets(fn)
+    {{dimx,dimy}} = scanf(line,"%d %d%s")
+    line = gets(fn)
+    {{maxcolor}} = scanf(line,"%d%s")
+    image = repeat(repeat(0,dimy),dimx)
+    for y=1 to dimy do
+        for x=1 to dimx do
+            image[x][y] = getc(fn)*#10000 + getc(fn)*#100 + getc(fn)
+        end for
+    end for
+    close(fn)
+    return image
+end function
+
+--include ppm.e   -- read_ppm(), write_ppm(), to_grey()  (as distributed, instead of the above)
+
+sequence img = read_ppm("Lena.ppm")
+img = to_grey(img)
+write_ppm("LenaGray.ppm",img)