diff --git a/source/blender/imbuf/intern/format_png.cc b/source/blender/imbuf/intern/format_png.cc
index 87b866dffd7..aac42ec6be0 100644
--- a/source/blender/imbuf/intern/format_png.cc
+++ b/source/blender/imbuf/intern/format_png.cc
@@ -13,7 +13,11 @@ extern "C" {
 
 bool imb_is_a_png(const uchar *mem, size_t size)
 {
-  return imb_oiio_check(mem, size, "png");
+  const char signature[] = {0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A};
+  if (size < sizeof(signature)) {
+    return false;
+  }
+  return memcmp(signature, mem, sizeof(signature)) == 0;
 }
 
 ImBuf *imb_load_png(const uchar *mem, size_t size, int flags, char colorspace[IM_MAX_SPACE])
diff --git a/source/blender/imbuf/intern/format_psd.cc b/source/blender/imbuf/intern/format_psd.cc
index 21c97108d75..0ebfebb43ce 100644
--- a/source/blender/imbuf/intern/format_psd.cc
+++ b/source/blender/imbuf/intern/format_psd.cc
@@ -13,7 +13,11 @@ extern "C" {
 
 bool imb_is_a_psd(const uchar *mem, size_t size)
 {
-  return imb_oiio_check(mem, size, "psd");
+  const uchar magic[4] = {'8', 'B', 'P', 'S'};
+  if (size < sizeof(magic)) {
+    return false;
+  }
+  return memcmp(magic, mem, sizeof(magic)) == 0;
 }
 
 ImBuf *imb_load_psd(const uchar *mem, size_t size, int flags, char colorspace[IM_MAX_SPACE])
diff --git a/source/blender/imbuf/intern/format_tiff.cc b/source/blender/imbuf/intern/format_tiff.cc
index b779e3973de..e46e4db5bf2 100644
--- a/source/blender/imbuf/intern/format_tiff.cc
+++ b/source/blender/imbuf/intern/format_tiff.cc
@@ -13,7 +13,15 @@ extern "C" {
 
 bool imb_is_a_tiff(const uchar *mem, size_t size)
 {
-  return imb_oiio_check(mem, size, "tif");
+  constexpr int MAGIC_SIZE = 4;
+  if (size < MAGIC_SIZE) {
+    return false;
+  }
+
+  const char big_endian[MAGIC_SIZE] = {0x4d, 0x4d, 0x00, 0x2a};
+  const char lil_endian[MAGIC_SIZE] = {0x49, 0x49, 0x2a, 0x00};
+  return ((memcmp(big_endian, mem, MAGIC_SIZE) == 0) ||
+          (memcmp(lil_endian, mem, MAGIC_SIZE) == 0));
 }
 
 ImBuf *imb_load_tiff(const uchar *mem, size_t size, int flags, char colorspace[IM_MAX_SPACE])
diff --git a/source/blender/imbuf/intern/oiio/openimageio_support.cc b/source/blender/imbuf/intern/oiio/openimageio_support.cc
index 34bd9225182..ba8e5cc5de3 100644
--- a/source/blender/imbuf/intern/oiio/openimageio_support.cc
+++ b/source/blender/imbuf/intern/oiio/openimageio_support.cc
@@ -225,6 +225,9 @@ static ImBuf *get_oiio_ibuf(ImageInput *in, const ReadContext &ctx, char colorsp
       ibuf->flags |= spec.extra_attribs.empty() ? 0 : IB_metadata;
 
       for (const auto &attrib : spec.extra_attribs) {
+        if (attrib.name().find("ICCProfile") != string::npos) {
+          continue;
+        }
         IMB_metadata_set_field(ibuf->metadata, attrib.name().c_str(), attrib.get_string().c_str());
       }
     }
diff --git a/source/blender/imbuf/intern/util.cc b/source/blender/imbuf/intern/util.cc
index 286d8dfde83..ed8a5358ef1 100644
--- a/source/blender/imbuf/intern/util.cc
+++ b/source/blender/imbuf/intern/util.cc
@@ -88,8 +88,8 @@ const char *imb_ext_audio[] = {
     nullptr,
 };
 
-/* Increased from 32 to 64 because of the bitmaps header size. */
-#define HEADER_SIZE 64
+/* OIIO will validate the entire header of some files and DPX requires 2048 */
+#define HEADER_SIZE 2048
 
 static ssize_t imb_ispic_read_header_from_filepath(const char *filepath, uchar buf[HEADER_SIZE])
 {