Color Faxes over VoIP

With Venta Fax & Voice you can send and receive Color Faxes via Fax Voip Virtual COM Ports, that is via VOIP network. You can send and receive Color Faxes both in T.38 and audio (fax over G.711) fax modes. In order to successfully send and receive Color Faxes the following requirements should be met:

• Color faxes are always sent and received with ECM (Error Correction Mode) enabled. Fax Voip should be also configured with ECM enabled.
• Color faxes are always sent and received in Fine Resolution (200*200 dpi).
• Errors within the data being transmitted are not allowed. The quality of VOIP termination should be enough good , especially when transferring color faxes in audio (fax over G.711) mode.
• To do color faxes possible, appropriate VentaFax Printer and Venta Fax program settings should be done.
• The other party must have hardware or software installed that allows the sending and receiving of color faxes.
• To send and receive Color Faxes via VOIP, you should download and install Venta Fax Software and configure it to work with Fax Voip. Basic instructions on how to setup Venta Fax to work with Fax Voip can be found here. 

We have also tested some other programs to send and receive Color Faxes. Unfortunately, all the other software implementations for Color Faxes are very poor and can not be used to send and receive Color Faxes over VOIP networks, no matter which side they are.

Notes

• Color Faxes are not currently supported with Fax Voip built-in SIP Fax Lines.  

VOIP Network Requirements for Color Faxes 

Color faxes are always sent and received with ECM (Error Correction Mode) enabled. Practice shows that some VOIP providers for some reason do not provide support for Error Correction Mode and this does not depend on the Fax Voip or Venta Fax settings. Note that sending and receiving of color faxes is not possible in this case.

At the same time, errors within the data being transmitted are not allowed. Experiments show that when using VOIP providers with poor quality of the termination, transfer of a color fax usually fails. Nevertheless transfer of black and white faxes can be quite successful in the cases described. This notification is especially true for color faxes transmitted in audio (fax over G.711) mode.

Thus, the requirements for VOIP network to send and receive color faxes can be formulated as follows:

• ECM (Error Correction Mode) for faxes should be enabled in your VOIP network.
• The quality of VOIP termination should be good enough.

To configure Fax Voip to send and receive Color Faxes

Color faxes are always sent and received with ECM (Error Correction Mode) enabled. Therefore, you must enable ECM in Fax Voip settings. Note that ECM is always enabled in T.38 fax mode. Thus, if you do not plan to send and receive color faxes in audio (fax over G.711) mode, additional configuration is not required.

At the same time, errors within the data being transmitted are not allowed. Experiments show that when sending and receiving color faxes in audio (fax over G.711) mode at 14400 bitrate, transfer of a color fax usually fails. It is recommended to send and receive color faxes in audio mode with maximum bitrate of 9600.

To provide sending and receiving of color faxes in audio fax mode, do the following: 

1. Open your Fax Voip FaxModem Control Panel.
2. Click Fax in TreeView, then click ECM/Rate. 



3. In section Modem (COM port) lines, subsection G711 audio fax check ECM option (necessary).
4. In section Modem (COM port) lines, subsection G711 audio fax, in the Maximum bitrate field, select 9600 (recommended).

Click <Apply> button to save settings.

To configure Venta Fax to send Color Faxes

To configure sending of color faxes, do the following:

1. Click Start, point to Settings, then click Printers (Printers and Faxes).
2. In the Printers (Printers and Faxes) folder, right-click Ventafax, and then click Properties in the menu.
3. In the Ventafax Properties window, in the General panel, click Printing Preferences button. 



4. In the Ventafax Printing Preferences window, in the Paper/Quality panel, in the Color pane select Color option, then click Apply. 



5. Click Advanced button to view VentaFax Advanced Options.
6. In the VentaFax Advanced Options window, select Print Quality: 200x200 dots per inch. Color faxes are always sent and received in Fine Resolution (200*200 dpi). 



7. Select Color Printing Mode: True Color (24bpp).
8. Select Compression for color tiff: LZW (recommended). LZW method provides compression with no reduction in quality. This is particularly important if the color fax you create will be sent to different fax machines and if it is not known beforehand whether they operate in color mode or in black-and-white only. The highest quality of black-and-white faxes is achieved when the original color fax has been generated without reduction in quality.
9. Click OK to return to the Ventafax Printing Preferences window.
10. In the Ventafax Printing Preferences window, click Apply, then click OK.
11. In the Ventafax Properties window, click OK.
12. In the Venta Fax main window, click Settings button.
13. In the Program settings window, select Fax, then select Format. 



14. In the Fax-Format pane, click Color Faxes.
15. In the Color Faxes panel, in the pane Fax quality for transmission set the desired value of Fax Quality. Do not use too high quality, because it greatly increases the volume of data transmitted and hence the time of fax transmission. Using of poor quality leads to strong distortion of transmitted images, and also can not be recommended. According to our observations, using the Quality=20 gives a small transmission time (about 3 minutes for photos at rate of 14400) while maintaining the normal image quality, so can be recommended.
16. Click Apply button to save settings.

Notes

• The volume of data transmitted through a telephone line does not depend directly on the size of the generated file. During transmission the data undergoes additional compression. The degree of compression, as well as the resulting quality, is determined by the setting Fax quality during transmission, accessible under the tab Fax - Format - Color fax
• When  generating a fax document it is recommended you use LZW compression (for color faxes this is set as the default, see in the VentaFax Advanced Options printer settings). It is true that the file size can end up being several times greater than with JPEG compression. However, this will not affect the volume of data transmitted.
• If a recipient's fax machine is unable to receive color faxes, the Venta Fax has to convert the fax document into black-and-white format. And a black-and-white fax message that has been converted from a color fax with JPEG compression of average or minimal quality could very well display some defects. For example, it might have unsightly extra dots around black symbols. So it is better to generate fax documents using LZW compression, to ensure there is no reduction in quality.
• Another argument in favor of LZW, is that TIFF files compressed with this method can be viewed using standard Windows tools. In contrast, to view TIFF files compressed with JPEG one would need additional image viewing software having advanced features (for example, ACDSee Image Viewer).

To configure Venta Fax to receive Color Faxes 

To configure receiving of color faxes , do the following: 

1. In the Venta Fax main window, click Settings button.
2. In the Program settings window, select Fax, then select Format. 

   

3. In the Fax-Format pane, click Color Faxes.
4. In the Color Faxes panel, in the pane Incoming fax compression method, select LZW (recommended).
5. Click Apply button to save settings.

Notes

• The volume of data received through a telephone line does not depend on Venta Fax settings in the case of incoming faxes.
• When  saving a fax document it is recommended you use LZW compression. It is true that the file size can end up being several times greater than with JPEG compression. However, TIFF files compressed with this method can be viewed using standard Windows tools. In contrast, to view TIFF files compressed with JPEG one would need additional image viewing software having advanced features (for example, ACDSee Image Viewer).

Remote Party Requirements for Color Faxes 

The other party must have hardware or software installed that allows the sending and receiving of Color Faxes. As the software, the other party can also use Venta Fax & Voice to send and receive Color Faxes. Note that Venta Fax can be used at PSTN line together with hardware modem. We have also tested some other programs to send and receive Color Faxes. Unfortunately, all the other software implementations for Color Faxes are very poor and can not be used to send and receive Color Faxes over VOIP networks, no matter which side they are.

If the receiving fax machine does not have color fax support, a color fax will be automatically converted into a black-and-white version at the time of transmission. 

Sending Color Faxes with Venta Fax & Voice 

In order to send a Color Fax, make the appropriate settings and follow the instructions in the Send a Fax with Venta Fax & Voice section in the Using Fax Voip with Venta Fax & Voice manual.

If the fax is really transmitted in color mode, you will see "Sending page (color)" in the Venta Fax main window.

Receiving Color Faxes with Venta Fax & Voice 

In order to receive faxes, follow the instructions in the To Receive Incoming Fax and Voice Messages section of this chapter. Venta Fax will automatically detect incoming Color Faxes.

If the fax is received in color mode, you will see "Receiving page (color)" in the in the Using Fax Voip with Venta Fax & Voice manual.