From 03e01bdd3e552da632a9b5e853d2efa3540c02d9 Mon Sep 17 00:00:00 2001
From: Liam <30486941+liamHowatt@users.noreply.github.com>
Date: Thu, 29 Aug 2024 13:04:15 -0400
Subject: [PATCH] fix(png): use color rounding like img conv tool (#6626)

---
 src/extra/libs/png/lv_png.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/extra/libs/png/lv_png.c b/src/extra/libs/png/lv_png.c
index a8171f2c4..75b196c1c 100644
--- a/src/extra/libs/png/lv_png.c
+++ b/src/extra/libs/png/lv_png.c
@@ -28,6 +28,7 @@ static lv_res_t decoder_info(struct _lv_img_decoder_t * decoder, const void * sr
 static lv_res_t decoder_open(lv_img_decoder_t * dec, lv_img_decoder_dsc_t * dsc);
 static void decoder_close(lv_img_decoder_t * dec, lv_img_decoder_dsc_t * dsc);
 static void convert_color_depth(uint8_t * img, uint32_t px_cnt);
+static inline lv_color_t lv_color_make_rounding(uint8_t r, uint8_t g, uint8_t b);
 
 /**********************
  *  STATIC VARIABLES
@@ -246,7 +247,7 @@ static void convert_color_depth(uint8_t * img, uint32_t px_cnt)
     lv_color_t c;
     uint32_t i;
     for(i = 0; i < px_cnt; i++) {
-        c = lv_color_make(img_argb[i].ch.blue, img_argb[i].ch.green, img_argb[i].ch.red);
+        c = lv_color_make_rounding(img_argb[i].ch.blue, img_argb[i].ch.green, img_argb[i].ch.red);
         img[i * 3 + 2] = img_argb[i].ch.alpha;
         img[i * 3 + 1] = c.full >> 8;
         img[i * 3 + 0] = c.full & 0xFF;
@@ -256,7 +257,7 @@ static void convert_color_depth(uint8_t * img, uint32_t px_cnt)
     lv_color_t c;
     uint32_t i;
     for(i = 0; i < px_cnt; i++) {
-        c = lv_color_make(img_argb[i].ch.red, img_argb[i].ch.green, img_argb[i].ch.blue);
+        c = lv_color_make_rounding(img_argb[i].ch.red, img_argb[i].ch.green, img_argb[i].ch.blue);
         img[i * 2 + 1] = img_argb[i].ch.alpha;
         img[i * 2 + 0] = c.full;
     }
@@ -272,4 +273,15 @@ static void convert_color_depth(uint8_t * img, uint32_t px_cnt)
 #endif
 }
 
+static inline lv_color_t lv_color_make_rounding(uint8_t r, uint8_t g, uint8_t b)
+{
+#if LV_COLOR_DEPTH == 16
+    if(r <= 251) r += 4;
+    if(g <= 253) g += 2;
+    if(b <= 251) b += 4;
+#endif
+
+    return lv_color_make(r, g, b);
+}
+
 #endif /*LV_USE_PNG*/