Could you please support translate System.Drawing.Bitmap to TesseractOCR.Pix like charlesw ?

[zhangqi-ulua]

https://github.com/charlesw/tesseract/blob/9df02d55744cebdd504dd27c65a02d20e6d07a5a/src/Tesseract/PixConverter.cs

[zhangqi-ulua]

All old Project use System.Drawing.Bitmap to load and edit image files, so it might be better to support like https://github.com/charlesw/tesseract/blob/9df02d55744cebdd504dd27c65a02d20e6d07a5a/src/Tesseract/TesseractDrawingExtensions.cs

[Sicos1977]

I'm not going to support the BitMap object because that is a .NET4.x Windows thing but if you need it you can always save your bitmap to a memorystream and then load it in the Pix object with this method

    #region LoadFromMemory
    /// <summary>
    ///     Loads an image from a MemoryStream
    /// </summary>
    /// <param name="memoryStream">The memory stream</param>
    /// <returns><see cref="Image"/></returns>
    /// <exception cref="IOException"></exception>
    public static Image LoadFromMemory(MemoryStream memoryStream)
    {
        Logger.LogInformation("Loading image from memory stream");
        var buffer = memoryStream.GetBuffer();
        return LoadFromMemoryInternal(buffer, 0, buffer.Length);
    }

[Sicos1977]

Just do this

var ms = new MemoryStream();
bitmap.Save(ms, System.Drawing.Imaging.ImageFormat.BMP);
TesseractOCR.Pix.Image.LoadFromMemory(ms.GetBuffer(), 0, ms.Length);

[zhangqi-ulua]

I'm not going to support the BitMap object because that is a .NET4.x Windows thing but if you need it you can always save your bitmap to a memorystream and then load it in the Pix object with this method

    #region LoadFromMemory
    /// <summary>
    ///     Loads an image from a MemoryStream
    /// </summary>
    /// <param name="memoryStream">The memory stream</param>
    /// <returns><see cref="Image"/></returns>
    /// <exception cref="IOException"></exception>
    public static Image LoadFromMemory(MemoryStream memoryStream)
    {
        Logger.LogInformation("Loading image from memory stream");
        var buffer = memoryStream.GetBuffer();
        return LoadFromMemoryInternal(buffer, 0, buffer.Length);
    }

Thanks for your reply. But, Bitmap also exist in .NET 6.0 and newest 7.0 ， My Projects use WinForm and WPF , just support Windows

[Sicos1977]

Yeah but even Microsoft does not recommend it to use it anymore that is why I dropped support for that.

https://docs.microsoft.com/en-us/dotnet/core/compatibility/core-libraries/6.0/system-drawing-common-windows-only

[zhangqi-ulua]

Yeah but even Microsoft does not recommend it to use it anymore that is why I dropped support for that.

https://docs.microsoft.com/en-us/dotnet/core/compatibility/core-libraries/6.0/system-drawing-common-windows-only

Ok,Thanks.

[Sicos1977]

But you should be fine to just use this ... If you don't OCR crazy amounts of data you won't notice any speed difference

var ms = new MemoryStream();
bitmap.Save(ms, System.Drawing.Imaging.ImageFormat.BMP);
TesseractOCR.Pix.Image.LoadFromMemory(ms.GetBuffer(), 0, ms.Length);

[zhangqi-ulua]

I know this way, but it's waste some memory space to store and CPU time. If the Engine.Process can support read Bitmap and do it ,it would be better

[Sicos1977]

I know this way, but it's waste some memory space to store and CPU time. If the Engine.Process can support read Bitmap and do it ,it would be better

Converting a Bitmap to Pix also takes times so I don't think it makes much difference

[zhangqi-ulua]

I know this way, but it's waste some memory space to store and CPU time. If the Engine.Process can support read Bitmap and do it ,it would be better

Converting a Bitmap to Pix also takes times so I don't think it makes much difference

No, I means support Engine.process(Bitmap, string, Mode), not translate Bitmap to Tesseract.Pix

[Sicos1977]

The Bitmap always needs to be translated to Pix because Tesseract does not understand Bitmap. What Charles his extension does is add an overload method that accepts a Bitmap but translated that in the background to Pix before feeding it to Tesseract

[Sicos1977]

In the background this method is called to process the page and that one only wants a Pix object

        /// <summary>
        ///     The recognized text is returned as a char* which is coded as UTF-8 and must be freed with the delete [] operator.
        /// 
        /// <summary>
        ///     The recognized text is returned as a char* which is coded as UTF-8 and must be freed with the delete [] operator.
        /// </summary>
        /// <param name="handle">The TesseractAPI instance</param>
        /// <param name="pix"></param>
        /// <param name="page_index"></param>
        /// <param name="filename"></param>
        /// <param name="retry_config"></param>
        /// <param name="timeout_millisec"></param>
        /// <param name="renderer"></param>
        /// <returns></returns>
        [RuntimeDllImport(Constants.TesseractDllName, CallingConvention = CallingConvention.Cdecl, EntryPoint = "TessBaseAPIProcessPage")]
        int BaseApiProcessPage(HandleRef handle, Pix.Image pix, int page_index, string filename, string retry_config, int timeout_millisec, HandleRef renderer);</summary>

[zhangqi-ulua]

In the background this method is called to process the page and that one only wants a Pix object

        /// <summary>
        ///     The recognized text is returned as a char* which is coded as UTF-8 and must be freed with the delete [] operator.
        /// 
        /// <summary>
        ///     The recognized text is returned as a char* which is coded as UTF-8 and must be freed with the delete [] operator.
        /// </summary>
        /// <param name="handle">The TesseractAPI instance</param>
        /// <param name="pix"></param>
        /// <param name="page_index"></param>
        /// <param name="filename"></param>
        /// <param name="retry_config"></param>
        /// <param name="timeout_millisec"></param>
        /// <param name="renderer"></param>
        /// <returns></returns>
        [RuntimeDllImport(Constants.TesseractDllName, CallingConvention = CallingConvention.Cdecl, EntryPoint = "TessBaseAPIProcessPage")]

Thank you very much