Resources Base
Table of contents


Only 24-bit true color bmp and 8-bit gray-scaled image are supported for JPEG compression

  • Symptom

When you save or upload an image as a JPEG file, you may receive the error.

  • Cause

You are saving a Black&White image as a JPEG file but JPEG standard only allows the compression of grayscale and RGB images.

  • Resolution

Make sure the pixel type of the image in the buffer is Gray or RGB. If it is not, you can either save it in another format or convert the image to grayscale using the method ConvertToGrayScale().

if ( /*If save in JPEG*/ ) {

    //Check whether the current image is B&W
    //1 is B&W, 8 is Gray, 24 is RGB
    if (DWObject.GetImageBitDepth(DWObject.CurrentImageIndexInBuffer) == 1)
        //If so, convert the image to Gray
    //Save image in JPEG
    DWObject.SaveAsJPEG("DynamicWebTWAIN.jpg", DWObject.CurrentImageIndexInBuffer);


Is this page helpful?

YesYes NoNo

In this article:

latest version

    • Latest Version
    • Version 17.0
    • Version 16.2
    • Version 16.1.1
    Change +
    © 2003–2021 Dynamsoft. All rights reserved.
    Privacy Statement / Site Map / Home / Purchase / Support