使用Imagemagick.NET删除透明度 [英] Removing Transparency using Imagemagick.NET

问题描述

我编写的软件包的一部分将采用二进制编码的PDF，将其转换为位图，然后将其保存到db中的blob中.我发现，尽管它不是立即以PDF格式显示在原始文档中，但文档中的透明度在转换后的位图中是完全可见的.

A part of a software package I've written takes in a binary encoded PDF, converts it to a Bitmap, and saves it to a blob in a db. I'm discovering that although it's not immediately visible in the original in it's PDF form, there is transparency in the document that is completely visible in the converted bitmap.

我看过​​其他帖子，其中该命令imagemagick的行版本可以展平"图像以除去透明层.可以通过.NET包完成此操作吗?如何在保存位图之前删除透明度?我需要将其保留为位图，因为它是标签打印机的通用格式.

I've seen other posts where the command line version of imagemagick can "flatten" an image to remove the transparency layers. Can this somehow be done with the .NET package? How do I remove the transparency before saving the bitmap? I need to keep it as a bitmap as it's a universally recognized format for their label printers.

    /// <summary>
    /// Write image data from a pdf file to a bitmap file
    /// </summary>
    /// <param name="imgData"></param>
    private static void convertPdfToBmp(ImageData imgData)
    {
        MagickReadSettings settings = new MagickReadSettings();
        // Settings the density to 600 dpi will create an image with a better quality
        settings.Density = new Density(600);

        using (MagickImageCollection images = new MagickImageCollection())
        {
            // Add all the pages of the pdf file to the collection
            images.Read(imgData.pdfFilePath, settings);

            // Create new image that appends all the pages horizontally
            using (IMagickImage image = images.AppendVertically())
            {
                // Convert the image to a bitmap
                image.Format = MagickFormat.Bmp;

                // Delete any old file 
                if (File.Exists(imgData.bmpFilePath))
                {
                    File.Delete(imgData.bmpFilePath);
                }
                // Save result as a bmp
                image.Write(imgData.bmpFilePath);
            }
        }
    }

我尝试使用不同的方法来调整透明层，或为背景着色而没有成功.

I have tried to use different methods of adjusting the transparency layers, or coloring of the background without success.

            //image.BackgroundColor = new ColorMono(false);
            //image.TransparentChroma(new MagickColor(0, 0, 0), new MagickColor(0, 0, 0));
            //image.TransparentChroma(new ColorRGB(0, 0, 0), new ColorRGB(65535, 65535, 65535));
            //image.BackgroundColor = new MagickColor("#fff");
            //image.BackgroundColor = new MagickColor("#ffffff");
            //image.BackgroundColor = new MagickColor("#ffffffffffff");
            //image.Settings.BackgroundColor.A = 0;

推荐答案

尝试删除Alpha组件，并根据输出设置背景色:

Try removing the Alpha component, and set the background color depending on the output:

image.Alpha(AlphaOption.Remove);

这篇关于使用Imagemagick.NET删除透明度的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！