Reduce file size of a print quality image with programmatic text without losing print quality

Question

I need to load an image file, set some text on it, and save it as an image for printing using the code below.       

 private static void A4SizeDpi600() {
                const int dotsPerInch = 600; // define the quality in DPI
                const double widthInInch = 10; // width of the bitmap in INCH
                const double heightInInch = 8; // height of the bitmap in INCH
    
                using (Bitmap bitmap = new Bitmap(Image.FromFile(imageFilePath), (int)(widthInInch * dotsPerInch), (int)(heightInInch * dotsPerInch))) //10*600=6000, 8*600=4800
                {
                    bitmap.SetResolution(dotsPerInch, dotsPerInch);
    
                    using (Graphics graphics = Graphics.FromImage(bitmap))
                    {
                      
                        graphics.DrawString("Some text here", new Font("Times New Roman", 0.3f, FontStyle.Regular, GraphicsUnit.Inch), Brushes.Black, 1400f, 2100f);
    ... //more text here
                    // Save the bitmap
                    bitmap.Save(imageBaseFilePath+ "CertDpi600.png");//file type can be any               
                }
            }

The problem is that the resulting image is too big (10MB), the input file is only 600K, which is more than 10 times in size . I want to know if there are ways to reduce the file size without losing printing quality.

The resulting image file type can be any type (pdf, png, bmp, jpeg), as long as it has good printing quality and small file size.

I am open to the input file type too (either any image file type, or pdf), as long as it produces the same requirement above.

Answer 1

Hi Pingpong689,

Sure you can reduce the picture with the following complete demo:

        public static string imageFilePath = @"C:\Users\v-baf\Desktop\Picon\8.jpg";
        public static string imageBaseFilePath = @"D:\New folder (9)\";

        private void button1_Click(object sender, EventArgs e)
        {
            A4SizeDpi600();

            Image img = Image.FromFile(imageBaseFilePath + "CertDpi600.png");
            SaveJpeg(imageBaseFilePath + "Result.png", img, 50);
        }

        private static void A4SizeDpi600()
        {
            const int dotsPerInch = 600; // define the quality in DPI
            const double widthInInch = 10; // width of the bitmap in INCH
            const double heightInInch = 8; // height of the bitmap in INCH
            using (Bitmap bitmap = new Bitmap(Image.FromFile(imageFilePath), (int)(widthInInch * dotsPerInch), (int)(heightInInch * dotsPerInch))) //10*600=6000, 8*600=4800
            {
                bitmap.SetResolution(dotsPerInch, dotsPerInch);

                using (Graphics graphics = Graphics.FromImage(bitmap))
                {

                    graphics.DrawString("Some text here", new Font("Times New Roman", 0.3f, FontStyle.Regular, GraphicsUnit.Inch), Brushes.Black, 1400f, 2100f);
                    //more text here
                    // Save the bitmap

                    bitmap.Save(imageBaseFilePath + "CertDpi600.png");//file type can be any 
                }
            }
        }

        public static void SaveJpeg(string path, Image img, int quality)
        {
            if (quality < 0 || quality > 100)
                throw new ArgumentOutOfRangeException("quality must be between 0 and 100.");

            // Encoder parameter for image quality 
            EncoderParameter qualityParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);
            // JPEG image codec 
            ImageCodecInfo jpegCodec = GetEncoderInfo("image/jpeg");
            EncoderParameters encoderParams = new EncoderParameters(1);
            encoderParams.Param[0] = qualityParam;

            img.Save(path, jpegCodec, encoderParams);
        }
        private static ImageCodecInfo GetEncoderInfo(string mimeType)
        {
            // Get image codecs for all image formats 
            ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();

            // Find the correct image codec 
            for (int i = 0; i < codecs.Length; i++)
                if (codecs[i].MimeType == mimeType)
                    return codecs[i];

            return null;
        }

The Result screenshot:

Refer to Reduce Image size C# [closed].

Hope this helps!

Best Regards,

Stanly

---

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Answer 2

Hi Stanly,

Thank you for your advice. I will try it, and let you know.

Regards

Answer 3

Hi Pingpong689,

So have you solved this problem now?

If so, hope you can close this thread by marking the reply as answer as this will help others looking for the same or similar issues down the road.

Best Regards,

Stanly

---

MSDN Community Support
Please remember to click "Mark as Answer" the responses that resolved your issue, and to click "Unmark as Answer" if not. This can be beneficial to other community members reading this thread. If you have any compliments or complaints to MSDN Support, feel free to contact [e-mail].

Answer 4

Hi,

Please give me some time. will test it asap.

Answer 5

Hi Pingpong689,

Have you solved this problem now?

Regards

---

MSDN Community Support
Please remember to click "Mark as Answer" the responses that resolved your issue, and to click "Unmark as Answer" if not. This can be beneficial to other community members reading this thread. If you have any compliments or complaints to MSDN Support, feel free to contact [e-mail].