Convert ICO to BMP: Free Online Converter
Convert Windows Icon to Bitmap Image online for free. Fast, secure image conversion with no watermarks or registration.
ICOに対応
アップロードすることで、これらのファイルの権利を有していること、および利用規約に同意することを確認したものとみなされます。
変換設定: ファイルを追加すると調整できます
安全な転送
HTTPS暗号化アップロード
プライバシー優先
ゲストのファイルは約2時間で自動削除
登録不要
すぐに変換を開始
どこでも動作
あらゆるブラウザ、あらゆるデバイス
ICO から BMP への設定
- エンジン
- 画像
- 設定
- 調整できる設定: 5
- Width (px)
- Height (px)
- Resize Mode
- Rotate upright
- Strip Metadata
変換方法
アップロードエリアにドラッグするか、クリックして選択し、.icoファイルをアップロードしてください。
必要に応じて出力設定を調整してください。デフォルト設定ではオリジナルの品質を維持します。
「変換」をクリックし、準備ができたら.bmpファイルをダウンロードしてください。
ICOからBMPへの変換について
ICO (Windows Icon) is a multi-resolution container format that embeds multiple images at standard sizes like 16x16, 32x32, 48x48, and 256x256 pixels within a single file. ICO files are used for Windows application icons and website favicons. BMP (Bitmap) is the simplest uncompressed raster format, storing raw pixel data that any image viewer or editor can open. Converting ICO to BMP extracts the largest embedded image from the ICO container and saves it as a flat, uncompressed bitmap.
This conversion is useful when you need to edit, inspect, or use an icon image in applications that do not understand the ICO multi-resolution container format. Most image editors, web platforms, and design tools cannot open ICO files directly but handle BMP without any issues.
ICOをBMPに変換する理由
ICO is a specialized format understood only by Windows shell, web browsers (for favicons), and a few icon editors. When you need to view, edit, or repurpose an icon image in a standard image editor like Photoshop, GIMP, or Paint.NET, converting to BMP provides the most straightforward uncompressed representation of the icon's pixel data.
BMP output is also useful for embedded systems, firmware, and legacy applications that need raw pixel data from icon images. Display controllers, boot screens, and custom OS shells that read BMP directly can use the extracted icon data without implementing ICO container parsing.
主な活用例
- Extract icon images from ICO files for editing in standard image editors
- Create uncompressed BMP versions of favicons for quality inspection and comparison
- Feed ICO icon data into embedded systems that only accept BMP input
- Generate editable BMP files from Windows application icons for redesign projects
- Convert ICO favicons to BMP for inclusion in documentation or style guides
仕組み
The ICO container is parsed to identify all embedded image entries and their resolutions. The largest resolution image (typically 256x256 for modern icons, or 48x48 for older icons) is extracted. If the 256x256 entry is stored as embedded PNG data (common in Windows Vista+ icons), it is decoded from PNG to raw pixels. Older ICO entries stored as BMP-format device-independent bitmaps are extracted directly. The pixel data is written as a standard Windows BMP v3 file with 24-bit (RGB) or 32-bit (RGBA) color depth. Alpha channel data from 32-bit ICO entries is preserved in the BMP output. Sharp handles the ICO decoding.
品質とパフォーマンス
No quality loss occurs during conversion. ICO images are stored either as uncompressed bitmaps or as lossless PNG data within the container. The BMP output is a pixel-perfect representation of the extracted icon image. The only limitation is resolution -- ICO images are small by design (typically 256x256 maximum), so the BMP output will also be small.
デバイス互換性
| Device | ICO | BMP |
|---|---|---|
| Windows PC | Native | Native |
| macOS | Partial | Partial |
| iPhone/iPad | Partial | Partial |
| Android | Partial | Partial |
| Linux | Partial | Partial |
| Web Browser | No | No |
最良の結果を得るためのヒント
- 1The largest resolution in the ICO is extracted -- check the output dimensions to confirm which size was used
- 2BMP files from ICO are typically very small since icon images are low-resolution by design
- 3For web use, consider converting to PNG instead of BMP for lossless quality with smaller file sizes
- 432-bit BMP preserves the ICO's alpha transparency mask for transparent icon backgrounds
- 5Use this conversion to extract favicon images for documentation or design reference
関連する変換
ICO to BMP extracts the highest-resolution icon image into a universally readable format. Use it when you need to edit or inspect icon images outside of specialized icon editors.
ICOとBMPの比較
| 特徴 | ICO | BMP |
|---|---|---|
| 正式名称 | Windows Icon | Bitmap Image |
| 拡張子 | .ico | .bmp |