SparkFun Forums

[donuan]

Hi,

I am using the GT-511C3 to capture fingerprints which I later receive in processing but I cant find any documentation on how to reconstruct the image.

I am downloading the images but they are deformed so something must be wrong.
in the datasheet it says that they should have the dimentions: 258x202 and 256x256 (which in itself is wierd) but neither seems correct as the image then is deformed.

any help would be much appriciated.
Thanks!

ps.
Im on mac so the demo software does not help me.

[jremington]

What do you mean by "reconstruct an image"? I suspect the manufacturer will not release information about the algorithm used to construct the template, so reverse engineering would be difficult.

The device allows you to save a raw image, which according to the documentation is 160x120 QVGA. The demo software includes the full source code, so you have all you need to determine the exact format.

[mrmellen]

Are you able to download the full image data from the reader? I've been using the GetImage and GetRawImage functions, and the reader consistently stops sending data after about 3500 bytes, instead of the expected 52000/19200 bytes. This is from a couple of different PCs, using both the demo software and my own test software, and two different readers.

[donuan]

I get the whole data packet. You need to change the baudrate to 115200 in order to get all of it.

[mrmellen]

Changing the baud rate did it. Thank you.

[donuan]

Changing the baud rate did it. Thank you.

Did you manage to display the image correctly? what dimentions does it have? in the documentation it states that they should be 258x202 and 256x256 but it appears to be neither.

[mrmellen]

The demo program does display what looks like a valid fingerprint image. I plan to work on this project over the holidays, so I will dig out the source code for the demo program and get answers for your questions.

[seulater]

Hi,

I am using the GT-511C3 to capture fingerprints which I later receive in processing but I cant find any documentation on how to reconstruct the image.

I am downloading the images but they are deformed so something must be wrong.
in the datasheet it says that they should have the dimentions: 258x202 and 256x256 (which in itself is wierd) but neither seems correct as the image then is deformed.

any help would be much appriciated.
Thanks!

ps.
Im on mac so the demo software does not help me.

we have done this long ago as you can see here.
http://www.versamodule.com/Video/NVMF/nvmf.html

In the attached code you should be able to figure it out.

Basically, the heart of this operations is like this say in your main file.

Code: Select all

	if(GT_511C3_CaptureFinger(1)==OK)
	{
		// Check for finger identity
		int rt = GT_511C3_Identify();
		iprintf("Identity Of Finger= %d\r\n",rt);


		if(rt>=0)
		{
			DisplayImage(160,30,Check);
			sprintf(lcdstring,"ACCEPTED");
			LCD_String(lcdstring,Elementary_Heavy_SF18x24,165,180,4,0x07e0,0x0000);

			sprintf(lcdstring,"Finger ID: %d",rt);
			LCD_String(lcdstring,Elementary_Heavy_SF18x24,2,210,4,0x2dd0,0x0000);

			confirmage = VALID;
		}
		else
		{
			DisplayImage(160,35,Close);
			sprintf(lcdstring,"DENIED");
			LCD_String(lcdstring,Elementary_Heavy_SF18x24,195,180,4,0xf800,0x0000);
			confirmage = ERROR;
		}


		// Get the actual image from sensor
		GT_511C3_GetRawImage(confirmage);

	}
	// Turn Finger Sensor Led Off
	GT_511C3_LED(0);