Improve OCR preprocessing and normalize merchant names

test/parser.test.js

@@ -12,6 +12,13 @@ import {
   rectFromPoints,
   resolveFieldRect,
 } from "../src/parser.js";
+import { isWhiteTextPixel } from "../src/vision.js";
+
+test("keeps white text pixels and removes colored or dark pixels", () => {
+  assert.equal(isWhiteTextPixel(220, 215, 195), true);
+  assert.equal(isWhiteTextPixel(210, 165, 80), false);
+  assert.equal(isWhiteTextPixel(120, 120, 120), false);
+});
 
 test("keeps only letters, digits and spaces in OCR item names", () => {
   assert.equal(cleanItemName(" ~~  Soulshot:   S-grade `  "), "Soulshot S grade");
@@ -139,5 +146,6 @@ test("parses trade side and merchant from the store header", () => {
     merchant: "Dwa",
     rawText: "Private Store({Sell) - Dwa",
   });
+  assert.equal(parseStoreHeaderText("Private Store(Buy) - Hik vision")?.merchant, "Hikvision");
   assert.equal(parseStoreHeaderText("Items on Sale"), null);
 });