depau/libfprint
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

aes2501: Improve image contrast

Browse source 
When scanning, check the histogram sum, and increase the
ADREFHI register value if the sum is too low, or decrease
it if it's too high.

https://bugs.freedesktop.org/show_bug.cgi?id=56715
This commit is contained in:
Vasily Khoruzhick 2012-11-03 16:13:05 +03:00 • committed by Bastien Nocera
parent d8aae30a67
commit e32fa8cc38
2 changed files with 21 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

17
libfprint/drivers/aes2501.c
View file

@ -515,13 +515,13 @@ static const struct aes_regwrite capture_reqs_2[] = {
{ AES2501_REG_CTRL2, AES2501_CTRL2_SET_ONE_SHOT }, { AES2501_REG_CTRL2, AES2501_CTRL2_SET_ONE_SHOT },
}; };
static const struct aes_regwrite strip_scan_reqs[] = { static struct aes_regwrite strip_scan_reqs[] = {
{ AES2501_REG_IMAGCTRL, { AES2501_REG_IMAGCTRL,
AES2501_IMAGCTRL_TST_REG_ENABLE | AES2501_IMAGCTRL_HISTO_DATA_ENABLE }, AES2501_IMAGCTRL_TST_REG_ENABLE | AES2501_IMAGCTRL_HISTO_DATA_ENABLE },
{ AES2501_REG_STRTCOL, 0x00 }, { AES2501_REG_STRTCOL, 0x00 },
{ AES2501_REG_ENDCOL, 0x2f }, { AES2501_REG_ENDCOL, 0x2f },
{ AES2501_REG_CHANGAIN, AES2501_CHANGAIN_STAGE1_16X }, { AES2501_REG_CHANGAIN, AES2501_CHANGAIN_STAGE1_16X },
{ AES2501_REG_ADREFHI, 0x5b }, { AES2501_REG_ADREFHI, AES2501_ADREFHI_MAX_VALUE },
{ AES2501_REG_ADREFLO, 0x20 }, { AES2501_REG_ADREFLO, 0x20 },
{ AES2501_REG_CTRL2, AES2501_CTRL2_SET_ONE_SHOT }, { AES2501_REG_CTRL2, AES2501_CTRL2_SET_ONE_SHOT },
}; };
@ -574,6 +574,17 @@ static void capture_read_strip_cb(struct libusb_transfer *transfer)
} }
fp_dbg("sum=%d", sum); fp_dbg("sum=%d", sum);
if (sum < AES2501_SUM_LOW_THRESH) {
strip_scan_reqs[4].value -= 0x8;
if (strip_scan_reqs[4].value < AES2501_ADREFHI_MIN_VALUE)
strip_scan_reqs[4].value = AES2501_ADREFHI_MIN_VALUE;
} else if (sum > AES2501_SUM_HIGH_THRESH) {
strip_scan_reqs[4].value += 0x8;
if (strip_scan_reqs[4].value > AES2501_ADREFHI_MAX_VALUE)
strip_scan_reqs[4].value = AES2501_ADREFHI_MAX_VALUE;
}
fp_dbg("ADREFHI is %.2x", strip_scan_reqs[4].value);
/* Sum is 0, maybe finger was removed? Wait for 3 empty frames /* Sum is 0, maybe finger was removed? Wait for 3 empty frames
* to ensure * to ensure
*/ */
@ -682,6 +693,8 @@ static void start_capture(struct fp_img_dev *dev)
} }
aesdev->no_finger_cnt = 0; aesdev->no_finger_cnt = 0;
/* Reset gain */
strip_scan_reqs[4].value = AES2501_ADREFHI_MAX_VALUE;
ssm = fpi_ssm_new(dev->dev, capture_run_state, CAPTURE_NUM_STATES); ssm = fpi_ssm_new(dev->dev, capture_run_state, CAPTURE_NUM_STATES);
fp_dbg(""); fp_dbg("");
ssm->priv = dev; ssm->priv = dev;

6
libfprint/drivers/aes2501.h
View file

@ -167,4 +167,10 @@ enum aes2501_sensor_gain2 {
#define AES2501_LPONT_MIN_VALUE 0x00 /* 0 ms */ #define AES2501_LPONT_MIN_VALUE 0x00 /* 0 ms */
#define AES2501_LPONT_MAX_VALUE 0x1f /* About 16 ms */ #define AES2501_LPONT_MAX_VALUE 0x1f /* About 16 ms */
#define AES2501_ADREFHI_MIN_VALUE 0x28
#define AES2501_ADREFHI_MAX_VALUE 0x58
#define AES2501_SUM_HIGH_THRESH 1000
#define AES2501_SUM_LOW_THRESH 700
#endif /* __AES2501_H */ #endif /* __AES2501_H */