lv_img_conv_py: first working version

img/lv_img_conv.py

@@ -2,6 +2,7 @@
 import argparse
 import pathlib
 import sys
+from PIL import Image
 
 parser = argparse.ArgumentParser()
 
@@ -36,9 +37,9 @@
 #  --dither, -d         enable dither                                   [boolean]
 args = parser.parse_args()
 
-img = pathlib.Path(args.img)
+img_path = pathlib.Path(args.img)
 out = pathlib.Path(args.output_file)
-if not img.is_file():
+if not img_path.is_file():
     print(f"Input file is missing: '{args.img}'")
     sys.exit(1)
 if out.exists():
@@ -48,3 +49,55 @@
         print(f"output-file exists, set --force to allow overwriting of file")
         sys.exit(0)
 out.touch()
+
+# only implemented the bare minimum, everything else is not implemented
+if args.color_format != "CF_TRUE_COLOR_ALPHA":
+    raise NotImplementedError(f"args.color_format '{args.color_format}' not implemented")
+if args.output_format != "bin":
+    raise NotImplementedError(f"args.output_format '{args.output_format}' not implemented")
+if args.binary_format != "ARGB8565_RBSWAP":
+    raise NotImplementedError(f"args.binary_format '{args.binary_format}' not implemented")
+
+img = Image.open(img_path)
+img.convert()
+
+def classify_pixel(value, bits):
+    tmp = 1 << (8 - bits)
+    val = round(value / tmp) * tmp
+    if val < 0:
+        val = 0
+    return val
+img_height = img.height
+img_width = img.width
+buf = bytearray(4 + img_height*img_width*3) # 4bytes header + 3 bytes (21 bit) per pixel
+print(f"loaded image with width x heigth: {img_width} x {img_height}")
+for y in range(img_height):
+    for x in range(img_width):
+        i = 4 + (y*img_width + x)*3 # buffer-index
+        pixel = img.getpixel((x,y))
+        r_act = classify_pixel(pixel[0], 5)
+        g_act = classify_pixel(pixel[1], 6)
+        b_act = classify_pixel(pixel[2], 5)
+        a = pixel[3]
+        if r_act > 0xF8:
+            r_act = 0xF8;
+        if g_act > 0xFC:
+            g_act = 0xFC;
+        if b_act > 0xF8:
+            b_act = 0xF8;
+        c16 = ((r_act) << 8) | ((g_act) << 3) | ((b_act) >> 3) # RGR565
+        buf[i + 0] = (c16 >> 8) & 0xFF
+        buf[i + 1] = c16 & 0xFF
+        buf[i + 2] = a
+
+# write header
+lv_cf = 5 # CF_TRUE_COLOR_ALPHA
+header_32bit = lv_cf | (img_width << 10) | (img_height << 21)
+buf[0] = header_32bit & 0xFF
+buf[1] = (header_32bit & 0xFF00) >> 8
+buf[2] = (header_32bit & 0xFF0000) >> 16
+buf[3] = (header_32bit & 0xFF000000) >> 24
+
+# write byte buffer to file
+with open(out, "wb") as f:
+    f.write(buf)