diff --git a/img2cpi.c b/img2cpi.c
new file mode 100644
index 0000000..67c603e
--- /dev/null
+++ b/img2cpi.c
@@ -0,0 +1,327 @@
+// x-run: ~/scripts/runc.sh % -Wall -Wextra -std=c99 -pedantic -lm --- ~/images/boykisser.png cpi-images/boykisser.cpi
+#define STB_IMAGE_IMPLEMENTATION
+#include <stb/stb_image.h>
+#define STB_IMAGE_RESIZE_IMPLEMENTATION
+#include <stb/stb_image_resize2.h>
+#include <argp.h>
+#include <stdio.h>
+#include <getopt.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <strings.h>
+#include <stdbool.h>
+
+#define MAX_COLOR_DIFFERENCE 768
+
+struct arguments {
+  bool text_mode;
+  int width, height;
+  enum cpi_version {
+    CPI_VERSION_AUTO,
+    CPI_VERSION_0,
+    CPI_VERSION_1,
+    CPI_VERSION_2,
+  } cpi_version;
+  enum placement {
+    PLACEMENT_CENTER,
+    PLACEMENT_COVER,
+    PLACEMENT_TILE,
+    PLACEMENT_FULL,
+    PLACEMENT_EXTEND,
+    PLACEMENT_FILL
+  } placement;
+  char *input_path;
+  char *output_path;
+} args = {
+  .text_mode = false,
+  .width = 4 * 8 - 1,
+  .height = 3 * 6 - 2,
+  .cpi_version = CPI_VERSION_AUTO,
+  .placement = PLACEMENT_FULL,
+  .input_path = NULL,
+  .output_path = NULL
+};
+
+struct image {
+  int w, h;
+  union color { // Alpha channel is not used, it's just there to align it all
+    struct rgba { uint8_t r, g, b, a; } rgba;
+    uint32_t v;
+  } *pixels;
+};
+
+bool parse_cmdline(int argc, char **argv);
+void show_help(const char *progname, bool show_all, FILE *fp);
+struct image *image_load(const char *fp);
+struct image *image_new(int w, int h);
+struct image *image_resize(struct image *original, int new_w, int new_h);
+struct image *image_dither(struct image *original, union color *colors, size_t n_colors);
+void image_unload(struct image *img);
+
+const char *known_file_extensions[] = {
+  ".png", ".jpg", ".jpeg", ".jfif", ".jpg", ".gif",
+  ".tga", ".bmp", ".hdr", ".pnm", 0
+};
+
+static const struct optiondocs {
+  char shortopt;
+  char *longopt;
+  char *target;
+  char *doc;
+  struct optiondocs_choice { char *value; char *doc; } *choices;
+} optiondocs[] = {
+  { 'h', "help",        0,            "Show help", 0 },
+  { 't', "textmode",    0,            "Output Lua script instead of binary", 0 },
+  { 'W', "width",       "width",      "Width in characters", 0 },
+  { 'h', "height",      "height",     "Height in characters", 0 },
+  { 'V', "cpi_version", "version",    "Force specific version of CPI",
+    (struct optiondocs_choice[]) {
+      { "-1", "Choose best available" },
+      { "0", "OG CPI, 255x255, uncompressed" },
+      { "1", "CPIv1, huge images, uncompressed" },
+      { "255", "In-dev version, may not work" },
+      { 0, 0 } } },
+  { 'p', "placement",   "placement",  "Image placement mode (same as in hsetroot)",
+    (struct optiondocs_choice[]){
+      { "center", "Render image centered on the canvas" },
+      { "cover",  "Centered on screen, scaled to fill fully" },
+      { "tile",   "Render image tiled" },
+      { "full",   "Use maximum aspect ratio" },
+      { "extend", "Same as \"full\", but filling borders" },
+      { "fill",   "Stretch to fill" },
+      { 0, 0 } } },
+  { 0,   0,             "input.*",    "Input file path", 0 },
+  { 0,   0,             "output.cpi", "Output file path", 0 },
+  { 0 }
+};
+
+int main(int argc, char **argv) {
+  if (!parse_cmdline(argc, argv)) {
+    show_help(argv[0], false, stderr);
+    fprintf(stderr, "Fatal error occurred, exiting.\n");
+    return EXIT_FAILURE;
+  }
+
+  struct image *src_image = image_load(args.input_path);
+  if (!src_image) {
+    fprintf(stderr, "Error: failed to open the file\n");
+    return EXIT_FAILURE;
+  }
+
+  struct image *canvas = image_new(args.width * 2, args.height * 3);
+  if (!canvas) {
+    fprintf(stderr, "Error: failed to allocate second image buffer\n");
+    return EXIT_FAILURE;
+  }
+
+  // TODO: actually do stuff
+
+  image_unload(src_image);
+  image_unload(canvas);
+  return EXIT_SUCCESS;
+}
+
+bool parse_cmdline(int argc, char **argv) {
+  static struct option options[] = {
+    { "help",         no_argument,        0, 'h' },
+    { "textmode",     no_argument,        0, 't' },
+    { "width",        required_argument,  0, 'W' },
+    { "height",       required_argument,  0, 'H' },
+    { "cpi_version",  required_argument,  0, 'V' },
+    { "placement",    required_argument,  0, 'p' },
+    { 0,              0,                  0,  0  }
+  };
+
+  while (true) {
+    int option_index = 0;
+    int c = getopt_long(argc, argv, "htW:H:V:p:", options, &option_index);
+    if (c == -1) break;
+    if (c == 0) c = options[option_index].val;
+    if (c == '?') break;
+
+    switch (c) {
+      case 'h':
+        show_help(argv[0], true, stdout);
+        exit(EXIT_SUCCESS);
+        break;
+      case 't':
+        args.text_mode = true;
+        if (args.cpi_version != CPI_VERSION_AUTO) {
+          fprintf(stderr, "Warning: text mode ignores version\n");
+        }
+        break;
+      case 'W':
+        args.width = atoi(optarg);
+        break;
+      case 'H':
+        args.height = atoi(optarg);
+        break;
+      case 'V':
+        {
+          int v = atoi(optarg);
+          if ((v < -1 || v > 1) && v != 255) {
+            fprintf(stderr, "Error: Invalid CPI version: %d\n", args.cpi_version);
+            return false;
+          }
+          args.cpi_version = v == -1 ? CPI_VERSION_AUTO : v;
+        }
+        break;
+      case 'p':
+        if (0 == strcmp(optarg, "center")) {
+          args.placement = PLACEMENT_CENTER;
+        } else if (0 == strcmp(optarg, "cover")) {
+          args.placement = PLACEMENT_COVER;
+        } else if (0 == strcmp(optarg, "tile")) {
+          args.placement = PLACEMENT_TILE;
+        } else if (0 == strcmp(optarg, "full")) {
+          args.placement = PLACEMENT_FULL; }
+        else if (0 == strcmp(optarg, "extend")) {
+          args.placement = PLACEMENT_EXTEND;
+        } else if (0 == strcmp(optarg, "fill")) {
+          args.placement = PLACEMENT_FILL;
+        } else {
+          fprintf(stderr, "Error: invaild placement %s\n", optarg);
+          return false;
+        }
+        break;
+    }
+  }
+
+  if (optind == argc) {
+    fprintf(stderr, "Error: no input file provided\n");
+    return false;
+  } else if (optind + 1 == argc) {
+    fprintf(stderr, "Error: no output file provided\n");
+    return false;
+  } else if ((argc - optind) != 2) {
+    fprintf(stderr, "Error: too many arguments\n");
+    return false;
+  }
+
+  args.input_path = argv[optind];
+  args.output_path = argv[optind + 1];
+
+  const char *extension = strrchr(args.input_path, '.');
+  if (!extension) {
+    fprintf(stderr, "Warning: no file extension, reading may fail!\n");
+  } else {
+    bool known = false;
+    for (int i = 0; known_file_extensions[i] != 0; i++) {
+      if (0 == strcasecmp(known_file_extensions[i], extension)) {
+        known = true;
+        break;
+      }
+    }
+    if (!known) {
+      fprintf(stderr, "Warning: unknown file extension %s, reading may fail!\n", extension);
+    }
+  }
+
+  return true;
+}
+
+void show_help(const char *progname, bool show_all, FILE *fp) {
+  fprintf(fp, "usage: %s", progname);
+  for (int i = 0; optiondocs[i].doc != 0; i++) {
+    struct optiondocs doc = optiondocs[i];
+    fprintf(fp, " [");
+    if (doc.shortopt) fprintf(fp, "-%c", doc.shortopt);
+    if (doc.shortopt && doc.longopt) fprintf(fp, "|");
+    if (doc.longopt) fprintf(fp, "--%s", doc.longopt);
+    if (doc.target) {
+      if (doc.shortopt || doc.longopt) fprintf(fp, " ");
+      fprintf(fp, "%s", doc.target);
+    }
+    fprintf(fp, "]");
+  }
+  fprintf(fp, "\n");
+
+  if (!show_all) return;
+
+  fprintf(fp, "\n");
+  fprintf(fp, "ComputerCraft Palette Image converter\n");
+  fprintf(fp, "\n");
+  fprintf(fp, "positional arguments:\n");
+  for (int i = 0; optiondocs[i].doc != 0; i++) {
+    struct optiondocs doc = optiondocs[i];
+    if (!doc.shortopt && !doc.longopt) {
+      fprintf(fp, "  %s\t%s\n", doc.target, doc.doc);
+    }
+  }
+  fprintf(fp, "\n");
+  fprintf(fp, "options:\n");
+  for (int i = 0; optiondocs[i].doc != 0; i++) {
+    struct optiondocs doc = optiondocs[i];
+    if (!doc.shortopt && !doc.longopt) { continue; }
+    fprintf(fp, "  ");
+    int x = 2;
+    if (doc.shortopt) { fprintf(fp, "-%c", doc.shortopt); x += 2; }
+    if (doc.shortopt && doc.longopt) { fprintf(fp, ", "); x += 2; }
+    if (doc.longopt) { fprintf(fp, "--%s", doc.longopt); x += strlen(doc.longopt) + 2; }
+    if (doc.choices) {
+      fprintf(fp, " {");
+      for (int j = 0; doc.choices[j].value != 0; j++) {
+        if (j > 0) { fprintf(fp, ","); x += 1; }
+        fprintf(fp, "%s", doc.choices[j].value);
+        x += strlen(doc.choices[j].value);
+      }
+      fprintf(fp, "}");
+      x += 3;
+    } else if (doc.target) {
+      fprintf(fp, " ");
+      fprintf(fp, "%s", doc.target);
+      x += strlen(doc.target) + 1;
+    }
+    if (x > 24) fprintf(fp, "\n%24c", ' ');
+    else fprintf(fp, "%*c", 24 - x, ' ');
+    fprintf(fp, "%s\n", doc.doc);
+    if (doc.choices) {
+      for (int j = 0; doc.choices[j].value != 0; j++) {
+        fprintf(fp, "%26c", ' ');
+        if (doc.shortopt) fprintf(fp, "-%c ", doc.shortopt);
+        else if (doc.longopt) fprintf(fp, "--%s", doc.longopt);
+        fprintf(fp, "%-12s %s\n", doc.choices[j].value, doc.choices[j].doc);
+      }
+    }
+  }
+}
+
+struct image *image_load(const char *fp) {
+  struct image *img = calloc(1, sizeof(struct image));
+  if (!img) return NULL;
+  img->pixels = (union color*)stbi_load(fp, &img->w, &img->h, 0, 4);
+  if (!img->pixels) {
+    free(img);
+    return NULL;
+  }
+  return img;
+}
+
+struct image *image_new(int w, int h) {
+  struct image *img = calloc(1, sizeof(struct image));
+  if (!img) return NULL;
+  img->pixels = calloc(h, sizeof(union color) * w);
+  img->w = w;
+  img->h = h;
+  if (!img->pixels) {
+    free(img);
+    return NULL;
+  }
+  return img;
+}
+
+struct image *image_resize(struct image *original, int new_w, int new_h) {
+  struct image *resized = image_new(new_w, new_h);
+  if (!resized) return NULL;
+  stbir_resize_uint8_srgb((unsigned char *)original->pixels, original->w, original->h, 0,
+                          (unsigned char *)resized->pixels, resized->w, resized->h, 0,
+                          STBIR_RGBA);
+  return resized;
+}
+
+void image_unload(struct image *img) {
+  free(img->pixels);
+  free(img);
+}
+