diff --git a/core/fpdfapi/page/cpdf_dib.cpp b/core/fpdfapi/page/cpdf_dib.cpp
index 0e11d9b..137053b 100644
--- a/core/fpdfapi/page/cpdf_dib.cpp
+++ b/core/fpdfapi/page/cpdf_dib.cpp
@@ -96,16 +96,6 @@
   return false;
 }
 
-int CalculateBitsPerPixel(uint32_t bpc, uint32_t comps) {
-  uint32_t bpp = bpc * comps;
-  CHECK(bpp);
-  if (bpp == 1)
-    return 1;
-  if (bpp <= 8)
-    return 8;
-  return 24;
-}
-
 CJPX_Decoder::ColorSpaceOption ColorSpaceOptionFromColorSpace(
     CPDF_ColorSpace* pCS) {
   if (!pCS) {
@@ -268,10 +258,18 @@
   if (m_bImageMask) {
     SetMaskProperties();
   } else {
-    if (!m_bpc || !m_nComponents)
+    const uint32_t bpp = m_bpc * m_nComponents;
+    if (bpp == 0) {
       return false;
+    }
 
-    SetFormat(MakeRGBFormat(CalculateBitsPerPixel(m_bpc, m_nComponents)));
+    if (bpp == 1) {
+      SetFormat(FXDIB_Format::k1bppRgb);
+    } else if (bpp <= 8) {
+      SetFormat(FXDIB_Format::k8bppRgb);
+    } else {
+      SetFormat(FXDIB_Format::kRgb);
+    }
   }
 
   std::optional<uint32_t> pitch = fxge::CalculatePitch32(GetBPP(), GetWidth());
diff --git a/core/fxge/dib/fx_dib.cpp b/core/fxge/dib/fx_dib.cpp
index d43ed3a..315e958 100644
--- a/core/fxge/dib/fx_dib.cpp
+++ b/core/fxge/dib/fx_dib.cpp
@@ -39,21 +39,6 @@
 static_assert(std::is_aggregate_v<FX_BGRA_STRUCT<float>>);
 static_assert(std::is_aggregate_v<FX_CMYK_STRUCT<float>>);
 
-FXDIB_Format MakeRGBFormat(int bpp) {
-  switch (bpp) {
-    case 1:
-      return FXDIB_Format::k1bppRgb;
-    case 8:
-      return FXDIB_Format::k8bppRgb;
-    case 24:
-      return FXDIB_Format::kRgb;
-    case 32:
-      return FXDIB_Format::kRgb32;
-    default:
-      return FXDIB_Format::kInvalid;
-  }
-}
-
 FXDIB_ResampleOptions::FXDIB_ResampleOptions() = default;
 
 bool FXDIB_ResampleOptions::HasAnyOptions() const {
diff --git a/core/fxge/dib/fx_dib.h b/core/fxge/dib/fx_dib.h
index d590241..59d1248 100644
--- a/core/fxge/dib/fx_dib.h
+++ b/core/fxge/dib/fx_dib.h
@@ -159,8 +159,6 @@
   return !!(static_cast<uint16_t>(format) & 0x100);
 }
 
-FXDIB_Format MakeRGBFormat(int bpp);
-
 FX_BGRA_STRUCT<uint8_t> ArgbToBGRAStruct(FX_ARGB argb);
 
 // Ignores alpha.