{"id":3211,"date":"2026-04-19T20:54:18","date_gmt":"2026-04-19T13:54:18","guid":{"rendered":"https:\/\/www.gocdidong.net\/index.php\/mat-do-diem-anh-ppi-la-gi-phan-biet-ppi-va-dpi-mot-cach-de-hieu\/"},"modified":"2026-04-19T20:54:18","modified_gmt":"2026-04-19T13:54:18","slug":"mat-do-diem-anh-ppi-la-gi-phan-biet-ppi-va-dpi-mot-cach-de-hieu","status":"publish","type":"post","link":"https:\/\/www.gocdidong.net\/index.php\/mat-do-diem-anh-ppi-la-gi-phan-biet-ppi-va-dpi-mot-cach-de-hieu\/","title":{"rendered":"M\u1eadt \u0111\u1ed9 \u0111i\u1ec3m \u1ea3nh PPI l\u00e0 g\u00ec? Ph\u00e2n bi\u1ec7t PPI v\u00e0 DPI m\u1ed9t c\u00e1ch d\u1ec5 hi\u1ec3u"},"content":{"rendered":"<p>Trong th\u1ebf gi\u1edbi c\u00f4ng ngh\u1ec7 hi\u1ec7n \u0111\u1ea1i, vi\u1ec7c l\u1ef1a ch\u1ecdn m\u1ed9t chi\u1ebfc \u0111i\u1ec7n tho\u1ea1i th\u00f4ng minh kh\u00f4ng ch\u1ec9 \u0111\u01a1n thu\u1ea7n l\u00e0 v\u1ec1 th\u01b0\u01a1ng hi\u1ec7u hay gi\u00e1 c\u1ea3. M\u1ed9t trong nh\u1eefng y\u1ebfu t\u1ed1 quan tr\u1ecdng m\u00e0 ng\u01b0\u1eddi ti\u00eau d\u00f9ng c\u1ea7n ch\u00fa \u00fd ch\u00ednh l\u00e0 m\u1eadt \u0111\u1ed9 \u0111i\u1ec3m \u1ea3nh PPI. \u0110i\u1ec1u n\u00e0y c\u00f3 th\u1ec3 \u1ea3nh h\u01b0\u1edfng l\u1edbn \u0111\u1ebfn tr\u1ea3i nghi\u1ec7m s\u1eed d\u1ee5ng c\u1ee7a b\u1ea1n. H\u00e3y c\u00f9ng kh\u00e1m ph\u00e1 kh\u00e1i ni\u1ec7m n\u00e0y v\u00e0 ph\u00e2n bi\u1ec7t r\u00f5 r\u00e0ng gi\u1eefa PPI v\u00e0 DPI.<\/p>\n<h2><strong>M\u1eadt \u0111\u1ed9 \u0111i\u1ec3m \u1ea3nh PPI l\u00e0 g\u00ec?<\/strong><\/h2>\n<p>M\u1eadt \u0111\u1ed9 \u0111i\u1ec3m \u1ea3nh PPI (Pixels Per Inch) l\u00e0 ch\u1ec9 s\u1ed1 th\u1ec3 hi\u1ec7n s\u1ed1 l\u01b0\u1ee3ng \u0111i\u1ec3m \u1ea3nh c\u00f3 tr\u00ean m\u1ed7i inch vu\u00f4ng c\u1ee7a m\u00e0n h\u00ecnh. \u0110\u01a1n gi\u1ea3n h\u01a1n, PPI cho bi\u1ebft m\u1ee9c \u0111\u1ed9 chi ti\u1ebft c\u1ee7a h\u00ecnh \u1ea3nh m\u00e0 m\u00e0n h\u00ecnh c\u00f3 th\u1ec3 hi\u1ec3n th\u1ecb. M\u1ed9t m\u00e0n h\u00ecnh c\u00f3 PPI cao s\u1ebd mang l\u1ea1i h\u00ecnh \u1ea3nh s\u1eafc n\u00e9t v\u00e0 m\u01b0\u1ee3t m\u00e0 h\u01a1n.<\/p>\n<ul>\n<li><strong>C\u00e1ch t\u00ednh PPI:<\/strong> \u0110\u1ec3 t\u00ednh PPI, b\u1ea1n ch\u1ec9 c\u1ea7n chia t\u1ed5ng s\u1ed1 \u0111i\u1ec3m \u1ea3nh tr\u00ean \u0111\u01b0\u1eddng ch\u00e9o m\u00e0n h\u00ecnh cho k\u00edch th\u01b0\u1edbc \u0111\u01b0\u1eddng ch\u00e9o \u0111\u00f3.<\/li>\n<li><strong>Ti\u00eau chu\u1ea9n Retina:<\/strong> Theo nghi\u00ean c\u1ee9u, m\u1eaft ng\u01b0\u1eddi kh\u00f3 c\u00f3 th\u1ec3 ph\u00e2n bi\u1ec7t c\u00e1c \u0111i\u1ec3m \u1ea3nh ri\u00eang l\u1ebb khi PPI \u0111\u1ea1t kho\u1ea3ng 300 \u1edf kho\u1ea3ng c\u00e1ch 25-30 cm.<\/li>\n<li><strong>Kho\u1ea3ng c\u00e1ch nh\u00ecn:<\/strong> Kho\u1ea3ng c\u00e1ch gi\u1eefa m\u1eaft v\u00e0 m\u00e0n h\u00ecnh c\u0169ng \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn \u0111\u1ed9 s\u1eafc n\u00e9t. Do \u0111\u00f3, \u0111i\u1ec7n tho\u1ea1i c\u1ea7n c\u00f3 PPI cao h\u01a1n so v\u1edbi TV 4K.<\/li>\n<li><strong>\u0110\u00e1nh \u0111\u1ed5i k\u1ef9 thu\u1eadt:<\/strong> Khi PPI v\u01b0\u1ee3t qu\u00e1 500, s\u1ef1 kh\u00e1c bi\u1ec7t v\u1ec1 ch\u1ea5t l\u01b0\u1ee3ng h\u00ecnh \u1ea3nh kh\u00f4ng c\u00f2n r\u00f5 r\u1ec7t, nh\u01b0ng l\u1ea1i ti\u00eau t\u1ed1n nhi\u1ec1u n\u0103ng l\u01b0\u1ee3ng v\u00e0 hi\u1ec7u su\u1ea5t x\u1eed l\u00fd.<\/li>\n<\/ul>\n<p>PPI l\u00e0 m\u1ed9t ch\u1ec9 s\u1ed1 quan tr\u1ecdng gi\u00fap b\u1ea1n \u0111\u00e1nh gi\u00e1 ch\u1ea5t l\u01b0\u1ee3ng m\u00e0n h\u00ecnh. H\u00e3y t\u01b0\u1edfng t\u01b0\u1ee3ng m\u1ed7i pixel nh\u01b0 m\u1ed9t h\u1ea1t g\u1ea1o. N\u1ebfu b\u1ea1n r\u1ea3i 100 h\u1ea1t g\u1ea1o tr\u00ean m\u1ed9t chi\u1ebfc \u0111\u0129a nh\u1ecf, b\u1ea1n s\u1ebd th\u1ea5y b\u1ec1 m\u1eb7t r\u1ea5t m\u1ecbn. Nh\u01b0ng n\u1ebfu r\u1ea3i tr\u00ean m\u1ed9t chi\u1ebfc m\u00e2m l\u1edbn, c\u00e1c kho\u1ea3ng tr\u1ed1ng s\u1ebd l\u1ed9 ra. T\u01b0\u01a1ng t\u1ef1, m\u00e0n h\u00ecnh v\u1edbi PPI cao s\u1ebd gi\u00fap h\u00ecnh \u1ea3nh hi\u1ec3n th\u1ecb r\u00f5 r\u00e0ng v\u00e0 s\u1eafc n\u00e9t h\u01a1n.<\/p>\n<h2><strong>Ph\u00e2n bi\u1ec7t PPI v\u00e0 DPI<\/strong><\/h2>\n<p>Nhi\u1ec1u ng\u01b0\u1eddi th\u01b0\u1eddng nh\u1ea7m l\u1eabn gi\u1eefa PPI v\u00e0 DPI (Dots Per Inch). Tuy nhi\u00ean, hai kh\u00e1i ni\u1ec7m n\u00e0y ho\u00e0n to\u00e0n kh\u00e1c nhau:<\/p>\n<ul>\n<li>\u0110\u1ed9 ph\u00e2n gi\u1ea3i m\u00e0n h\u00ecnh (nh\u01b0 Full HD, 2K, 4K) ch\u1ec9 cho bi\u1ebft t\u1ed5ng s\u1ed1 \u0111i\u1ec3m \u1ea3nh c\u00f3 tr\u00ean m\u00e0n h\u00ecnh, gi\u1ed1ng nh\u01b0 vi\u1ec7c b\u1ea1n bi\u1ebft c\u00f3 bao nhi\u00eau chi\u1ebfc gh\u1ebf trong m\u1ed9t ph\u00f2ng.<\/li>\n<li>PPI cho bi\u1ebft c\u00e1ch s\u1eafp x\u1ebfp c\u00e1c \u0111i\u1ec3m \u1ea3nh, t\u1ee9c l\u00e0 ch\u00fang c\u00f3 kh\u00edt nhau hay kh\u00f4ng. M\u1ed9t m\u00e0n h\u00ecnh l\u1edbn v\u1edbi \u0111\u1ed9 ph\u00e2n gi\u1ea3i th\u1ea5p s\u1ebd c\u00f3 PPI th\u1ea5p, d\u1eabn \u0111\u1ebfn h\u00ecnh \u1ea3nh b\u1ecb r\u1ed7.<\/li>\n<li>DPI \u0111o l\u01b0\u1eddng s\u1ed1 l\u01b0\u1ee3ng h\u1ea1t m\u1ef1c tr\u00ean m\u1ed7i inch c\u1ee7a m\u00e1y in, kh\u00f4ng li\u00ean quan \u0111\u1ebfn m\u00e0n h\u00ecnh \u0111i\u1ec7n tho\u1ea1i.<\/li>\n<\/ul>\n<p>V\u00ec v\u1eady, khi \u0111\u00e1nh gi\u00e1 m\u1ed9t chi\u1ebfc \u0111i\u1ec7n tho\u1ea1i, b\u1ea1n n\u00ean ch\u00fa \u00fd \u0111\u1ebfn PPI thay v\u00ec DPI.<\/p>\n<h2><strong>C\u00e1ch t\u00ednh PPI cho thi\u1ebft b\u1ecb<\/strong><\/h2>\n<p>\u0110\u1ec3 t\u00ednh PPI cho b\u1ea5t k\u1ef3 thi\u1ebft b\u1ecb n\u00e0o, b\u1ea1n c\u00f3 th\u1ec3 s\u1eed d\u1ee5ng \u0111\u1ecbnh l\u00fd Pytago. C\u00f4ng th\u1ee9c t\u00ednh PPI l\u00e0:<\/p>\n<p>PPI = \u221a(S\u1ed1 pixel chi\u1ec1u d\u00e0i\u00b2 + S\u1ed1 pixel chi\u1ec1u r\u1ed9ng\u00b2) \/ K\u00edch th\u01b0\u1edbc \u0111\u01b0\u1eddng ch\u00e9o<\/p>\n<p>\u00c1p d\u1ee5ng c\u00f4ng th\u1ee9c n\u00e0y, b\u1ea1n c\u00f3 th\u1ec3 d\u1ec5 d\u00e0ng so s\u00e1nh PPI c\u1ee7a c\u00e1c m\u1eabu \u0111i\u1ec7n tho\u1ea1i kh\u00e1c nhau.<\/p>\n<h2><strong>Ti\u00eau chu\u1ea9n PPI cho c\u00e1c thi\u1ebft b\u1ecb<\/strong><\/h2>\n<p>Nhi\u1ec1u ng\u01b0\u1eddi th\u1eafc m\u1eafc t\u1ea1i sao m\u1ed9t chi\u1ebfc TV 4K l\u1ea1i c\u00f3 PPI th\u1ea5p h\u01a1n so v\u1edbi m\u1ed9t chi\u1ebfc \u0111i\u1ec7n tho\u1ea1i Full HD. \u0110i\u1ec1u n\u00e0y ph\u1ee5 thu\u1ed9c v\u00e0o kho\u1ea3ng c\u00e1ch nh\u00ecn:<\/p>\n<table>\n<tr>\n<th><strong>Thi\u1ebft b\u1ecb hi\u1ec3n th\u1ecb<\/strong><\/th>\n<th><strong>K\u00edch th\u01b0\u1edbc<\/strong><\/th>\n<th><strong>\u0110\u1ed9 ph\u00e2n gi\u1ea3i<\/strong><\/th>\n<th><strong>PPI<\/strong><\/th>\n<th><strong>Kho\u1ea3ng c\u00e1ch nh\u00ecn<\/strong><\/th>\n<\/tr>\n<tr>\n<td>TV 4K ti\u00eau chu\u1ea9n<\/td>\n<td>65 inch<\/td>\n<td>3840 \u00d7 2160<\/td>\n<td>~68 ppi<\/td>\n<td>2 \u2013 3 m\u00e9t<\/td>\n<\/tr>\n<tr>\n<td>M\u00e0n h\u00ecnh m\u00e1y t\u00ednh<\/td>\n<td>27 inch<\/td>\n<td>2560 \u00d7 1440<\/td>\n<td>~109 ppi<\/td>\n<td>60 \u2013 80 cm<\/td>\n<\/tr>\n<tr>\n<td>Smartphone t\u1ea7m trung<\/td>\n<td>6.1 inch<\/td>\n<td>2340 \u00d7 1080<\/td>\n<td>~401 ppi<\/td>\n<td>30 \u2013 40 cm<\/td>\n<\/tr>\n<\/table>\n<p>Nh\u01b0 b\u1ea1n th\u1ea5y, m\u1eb7c d\u00f9 TV c\u00f3 k\u00edch th\u01b0\u1edbc l\u1edbn nh\u01b0ng PPI th\u1ea5p, nh\u01b0ng v\u1eabn mang l\u1ea1i h\u00ecnh \u1ea3nh s\u1eafc n\u00e9t nh\u1edd kho\u1ea3ng c\u00e1ch nh\u00ecn xa. Ng\u01b0\u1ee3c l\u1ea1i, \u0111i\u1ec7n tho\u1ea1i c\u1ea7n c\u00f3 PPI cao \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o h\u00ecnh \u1ea3nh r\u00f5 r\u00e0ng khi nh\u00ecn g\u1ea7n.<\/p>\n<h2><strong>Ch\u1ea5t l\u01b0\u1ee3ng hi\u1ec3n th\u1ecb v\u00e0 nhu c\u1ea7u s\u1eed d\u1ee5ng<\/strong><\/h2>\n<p>Ch\u1ea5t l\u01b0\u1ee3ng hi\u1ec3n th\u1ecb kh\u00f4ng ch\u1ec9 ph\u1ee5 thu\u1ed9c v\u00e0o PPI m\u00e0 c\u00f2n v\u00e0o c\u1ea5u t\u1ea1o c\u1ee7a t\u1eebng \u0111i\u1ec3m \u1ea3nh. V\u00ed d\u1ee5, m\u00e0n h\u00ecnh IPS LCD v\u00e0 OLED c\u00f3 c\u00e1ch s\u1eafp x\u1ebfp \u0111i\u1ec3m \u1ea3nh kh\u00e1c nhau, \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn tr\u1ea3i nghi\u1ec7m ng\u01b0\u1eddi d\u00f9ng. N\u1ebfu b\u1ea1n ch\u1ec9 s\u1eed d\u1ee5ng \u0111i\u1ec7n tho\u1ea1i \u0111\u1ec3 l\u01b0\u1edbt web hay xem video, PPI kho\u1ea3ng 350-400 l\u00e0 \u0111\u1ee7. Tuy nhi\u00ean, n\u1ebfu b\u1ea1n l\u00e0 ng\u01b0\u1eddi l\u00e0m vi\u1ec7c v\u1edbi h\u00ecnh \u1ea3nh ho\u1eb7c ch\u01a1i game, b\u1ea1n n\u00ean ch\u1ecdn thi\u1ebft b\u1ecb c\u00f3 PPI t\u1eeb 450 tr\u1edf l\u00ean.<\/p>\n<p>Cu\u1ed1i c\u00f9ng, vi\u1ec7c hi\u1ec3u r\u00f5 v\u1ec1 m\u1eadt \u0111\u1ed9 \u0111i\u1ec3m \u1ea3nh PPI s\u1ebd gi\u00fap b\u1ea1n \u0111\u01b0a ra quy\u1ebft \u0111\u1ecbnh th\u00f4ng minh h\u01a1n khi ch\u1ecdn mua thi\u1ebft b\u1ecb. H\u00e3y nh\u1edb r\u1eb1ng, m\u1ed9t m\u00e0n h\u00ecnh t\u1ed1t kh\u00f4ng ch\u1ec9 d\u1ef1a v\u00e0o con s\u1ed1 PPI m\u00e0 c\u00f2n ph\u1ea3i \u0111\u00e1p \u1ee9ng nhu c\u1ea7u s\u1eed d\u1ee5ng h\u00e0ng ng\u00e0y c\u1ee7a b\u1ea1n.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>M\u1eadt \u0111\u1ed9 \u0111i\u1ec3m \u1ea3nh ppi l\u00e0 g\u00ec? \u0110\u1ecbnh ngh\u0129a ch\u00ednh x\u00e1c PPI l\u00e0 g\u00ec, ph\u00e2n bi\u1ec7t v\u1edbi c\u00e1c kh\u00e1i ni\u1ec7m v\u1ec1 DPI, \u0111\u1ed9 ph\u00e2n gi\u1ea3i v\u00e0 c\u00e1ch t\u00ednh PPI chi ti\u1ebft. \u0110\u1ecdc b\u00e0i vi\u1ebft ngay!<\/p>\n","protected":false},"author":0,"featured_media":3212,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-3211","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-cong-nghe"],"_links":{"self":[{"href":"https:\/\/www.gocdidong.net\/index.php\/wp-json\/wp\/v2\/posts\/3211","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.gocdidong.net\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.gocdidong.net\/index.php\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/www.gocdidong.net\/index.php\/wp-json\/wp\/v2\/comments?post=3211"}],"version-history":[{"count":0,"href":"https:\/\/www.gocdidong.net\/index.php\/wp-json\/wp\/v2\/posts\/3211\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.gocdidong.net\/index.php\/wp-json\/wp\/v2\/media\/3212"}],"wp:attachment":[{"href":"https:\/\/www.gocdidong.net\/index.php\/wp-json\/wp\/v2\/media?parent=3211"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.gocdidong.net\/index.php\/wp-json\/wp\/v2\/categories?post=3211"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.gocdidong.net\/index.php\/wp-json\/wp\/v2\/tags?post=3211"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}