diff --git a/metainfo.xml b/metainfo.xml
index bbdf1f1206..164133d66e 100644
--- a/metainfo.xml
+++ b/metainfo.xml
@@ -107,7 +107,7 @@
     <release version="0.4.4" urgency="medium" type="development">
       <description>
         <ul>
-          <li> ... </li>
+          <li> Fixes corruption of sixel image on high resolution (#1049) </li>
         </ul>
       </description>
     </release>
diff --git a/src/vtbackend/Image.cpp b/src/vtbackend/Image.cpp
index 14bdfcf792..024dcc1039 100644
--- a/src/vtbackend/Image.cpp
+++ b/src/vtbackend/Image.cpp
@@ -60,9 +60,9 @@ Image::Data RasterizedImage::fragment(CellLocation pos) const
     Image::Data fragData;
     fragData.resize(_cellSize.area() * 4); // RGBA
     auto const availableWidth =
-        min(unbox<int>(_image->width()) - *pixelOffset.column, unbox<int>(_cellSize.width));
+        min(unbox<int>(_image->width()) - unbox(pixelOffset.column), unbox<int>(_cellSize.width));
     auto const availableHeight =
-        min(unbox<int>(_image->height()) - *pixelOffset.line, unbox<int>(_cellSize.height));
+        min(unbox<int>(_image->height()) - unbox(pixelOffset.line), unbox<int>(_cellSize.height));
 
     // auto const availableSize = Size{availableWidth, availableHeight};
     // std::cout << fmt::format(
@@ -90,7 +90,7 @@ Image::Data RasterizedImage::fragment(CellLocation pos) const
     for (int y = 0; y < availableHeight; ++y)
     {
         auto const startOffset = static_cast<size_t>(
-            ((*pixelOffset.line + y) * unbox<int>(_image->width()) + *pixelOffset.column) * 4);
+            ((pixelOffset.line + y) * unbox<int>(_image->width()) + unbox(pixelOffset.column)) * 4);
         const auto* const source = &_image->data()[startOffset];
         target = copy(source, source + static_cast<ptrdiff_t>(availableWidth) * 4, target);
 
diff --git a/src/vtbackend/Screen.cpp b/src/vtbackend/Screen.cpp
index db09924452..ec9cdf13b7 100644
--- a/src/vtbackend/Screen.cpp
+++ b/src/vtbackend/Screen.cpp
@@ -1887,9 +1887,9 @@ CRISPY_REQUIRES(CellConcept<Cell>)
 void Screen<Cell>::sixelImage(ImageSize pixelSize, Image::Data&& rgbaData)
 {
     auto const columnCount =
-        ColumnCount::cast_from(ceilf(float(*pixelSize.width) / float(*_state->cellPixelSize.width)));
+        ColumnCount::cast_from(ceil(pixelSize.width.as<double>() / _state->cellPixelSize.width.as<double>()));
     auto const lineCount =
-        LineCount::cast_from(ceilf(float(*pixelSize.height) / float(*_state->cellPixelSize.height)));
+        LineCount::cast_from(ceil(pixelSize.height.as<double>() / _state->cellPixelSize.height.as<double>()));
     auto const extent = GridSize { lineCount, columnCount };
     auto const autoScrollAtBottomMargin = !_terminal->isModeEnabled(DECMode::NoSixelScrolling);
     auto const topLeft = autoScrollAtBottomMargin ? logicalCursorPosition() : CellLocation {};
@@ -1939,29 +1939,30 @@ void Screen<Cell>::renderImage(shared_ptr<Image const> image,
 
     auto const linesAvailable = pageSize().lines - topLeft.line.as<LineCount>();
     auto const linesToBeRendered = min(gridSize.lines, linesAvailable);
-    auto const columnsAvailable = *pageSize().columns - *topLeft.column;
-    auto const columnsToBeRendered = ColumnCount(min(columnsAvailable, *gridSize.columns));
+    auto const columnsAvailable = pageSize().columns - topLeft.column;
+    auto const columnsToBeRendered = ColumnCount(min(columnsAvailable, gridSize.columns));
     auto const gapColor = RGBAColor {}; // TODO: _cursor.graphicsRendition.backgroundColor;
 
     // TODO: make use of imageOffset and imageSize
     auto const rasterizedImage = make_shared<RasterizedImage>(
         std::move(image), alignmentPolicy, resizePolicy, gapColor, gridSize, _state->cellPixelSize);
-    const auto lastSixelBand = imageSize.height.value % 6;
+    const auto lastSixelBand = unbox(imageSize.height) % 6;
     const LineOffset offset = [&]() {
         auto offset =
-            LineOffset::cast_from(std::ceil(static_cast<float>(imageSize.height.value - lastSixelBand)
-                                            / float(*_state->cellPixelSize.height)))
+            LineOffset::cast_from(std::ceil((imageSize.height - lastSixelBand).as<double>()
+                                            / _state->cellPixelSize.height.as<double>()))
             - 1 * (lastSixelBand == 0);
-        auto const h = imageSize.height.value - 1;
+        auto const h = unbox(imageSize.height) - 1;
         // VT340 has this behavior where for some heights it text cursor is placed not
         // at the final sixel line but a line above it.
         // See
         // https://github.com/hackerb9/vt340test/blob/main/glitches.md#text-cursor-is-left-one-row-too-high-for-certain-sixel-heights
-        if (h % 6 > h % _state->cellPixelSize.height.value)
+        if (h % 6 > h % unbox(_state->cellPixelSize.height))
             return offset - 1;
         return offset;
     }();
-    if (*linesToBeRendered)
+
+    if (unbox(linesToBeRendered))
     {
         for (GridSize::Offset const offset: GridSize { linesToBeRendered, columnsToBeRendered })
         {
diff --git a/src/vtbackend/SixelParser.h b/src/vtbackend/SixelParser.h
index fe4952d15d..6693687991 100644
--- a/src/vtbackend/SixelParser.h
+++ b/src/vtbackend/SixelParser.h
@@ -8,7 +8,6 @@
 
 #include <crispy/range.h>
 
-#include <array>
 #include <memory>
 #include <optional>
 #include <string_view>
diff --git a/src/vtbackend/primitives.h b/src/vtbackend/primitives.h
index 75ecdfdfa1..6884d8744b 100644
--- a/src/vtbackend/primitives.h
+++ b/src/vtbackend/primitives.h
@@ -353,12 +353,12 @@ struct GridSize
 
         constexpr Offset makeOffset(int offset) noexcept
         {
-            return Offset { LineOffset(offset / *_width), ColumnOffset(offset % *_width) };
+            return Offset { LineOffset(offset / unbox(_width)), ColumnOffset(offset % unbox(_width)) };
         }
     };
 
     [[nodiscard]] constexpr iterator begin() const noexcept { return iterator { columns, 0 }; }
-    [[nodiscard]] constexpr iterator end() const noexcept { return iterator { columns, *columns * *lines }; }
+    [[nodiscard]] constexpr iterator end() const noexcept { return iterator { columns, unbox(columns) * unbox(lines) }; }
 };
 
 constexpr CellLocation operator+(CellLocation a, GridSize::Offset b) noexcept
diff --git a/src/vtpty/PageSize.h b/src/vtpty/PageSize.h
index 495b95cde9..af90069cf9 100644
--- a/src/vtpty/PageSize.h
+++ b/src/vtpty/PageSize.h
@@ -28,7 +28,7 @@ struct PageSize
     LineCount lines;
     ColumnCount columns;
 
-    [[nodiscard]] int area() const noexcept { return *lines * *columns; }
+    [[nodiscard]] int area() const noexcept { return unbox(lines) * unbox(columns); }
 };
 
 constexpr PageSize operator+(PageSize pageSize, LineCount lines) noexcept
diff --git a/src/vtrasterizer/Renderer.cpp b/src/vtrasterizer/Renderer.cpp
index bb8bf45713..1f96cbb492 100644
--- a/src/vtrasterizer/Renderer.cpp
+++ b/src/vtrasterizer/Renderer.cpp
@@ -116,7 +116,10 @@ Renderer::Renderer(vtbackend::PageSize pageSize,
                    Decorator hyperlinkNormal,
                    Decorator hyperlinkHover):
     _atlasHashtableSlotCount { crispy::nextPowerOfTwo(atlasHashtableSlotCount.value) },
-    _atlasTileCount { std::max(atlasTileCount.value, static_cast<uint32_t>(pageSize.area())) },
+    _atlasTileCount {
+        std::max(atlasTileCount.value, static_cast<uint32_t>(pageSize.area() * 3))
+    }, // TODO instead of pagesize use size for fullscreen window
+       // 3 required for huge sixel images rendering due to initial page size smaller than
     _atlasDirectMapping { atlasDirectMapping },
     //.
     _fontDescriptions { std::move(fontDescriptions) },