单击扫描按钮后，扫描仪开始扫描时，应用程序关闭（核心转储）。Brother MFC L2750DW 通过 USB 连接，simplescan 是最新版本。simple-scan 已经是最新版本（3.20.0-0ubuntu1）。
dmesg 日志：
[ 534.647562] usb 1-1: USB disconnect, device number 2
[ 534.647720] usblp0: removed
[ 544.048024] usb 1-1: new high-speed USB device number 3 using ehci-pci
[ 544.180971] usb 1-1: New USB device found, idVendor=04f9, idProduct=043a
[ 544.180975] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 544.180979] usb 1-1: Product: MFC-L2750DW series
[ 544.180982] usb 1-1: Manufacturer: Brother
[ 544.180984] usb 1-1: SerialNumber: E78115L7N286679
[ 544.183377] usblp 1-1:1.0: usblp0: USB Bidirectional printer dev 3 if 0 alt 0 proto 2 vid 0x04F9 pid 0x043A
[ 588.518742] usb 1-1: usbfs: interface 0 claimed by usblp while 'scan-thread' sets config #1
[ 588.518772] usb 1-1: usbfs: process 4387 (scan-thread) did not claim interface 1 before use
[ 589.757458] usb 1-1: usbfs: interface 0 claimed by usblp while 'scan-thread' sets config #1
[ 589.757477] usb 1-1: usbfs: process 4387 (scan-thread) did not claim interface 1 before use
[ 669.868311] usb 1-1: usbfs: interface 0 claimed by usblp while 'scan-thread' sets config #1
[ 669.868342] usb 1-1: usbfs: process 5213 (scan-thread) did not claim interface 1 before use
[ 671.105444] usb 1-1: usbfs: interface 0 claimed by usblp while 'scan-thread' sets config #1
[ 671.105465] usb 1-1: usbfs: process 5213 (scan-thread) did not claim interface 1 before use
[ 675.906193] scan-thread[5213]: segfault at 3ec ip 00007f12109cb26f sp 00007f1212547870 error 4 in libsane-brother4.so.1.0.7[7f12109b6000+25000]
来自 simplescan --debug 日志：
[+6.95s] DEBUG: scanner.vala:546: sane_control_option (4, SANE_ACTION_SET_VALUE, "FlatBed") -> (SANE_STATUS_GOOD, "FlatBed")
[+6.95s] DEBUG: scanner.vala:546: sane_control_option (2, SANE_ACTION_SET_VALUE, "24bit Color") -> (SANE_STATUS_GOOD, "24bit Color")
[+6.95s] DEBUG: scanner.vala:462: sane_control_option (3, SANE_ACTION_SET_VALUE, 300) -> (SANE_STATUS_GOOD, 300)
[+6.95s] DEBUG: scanner.vala:502: sane_control_option (10, SANE_ACTION_SET_VALUE, 210.000000) -> (SANE_STATUS_GOOD, 209.980774)
[+6.95s] DEBUG: scanner.vala:502: sane_control_option (11, SANE_ACTION_SET_VALUE, 297.000000) -> (SANE_STATUS_GOOD, 296.972809)
[+11.18s] DEBUG: scanner.vala:1213: sane_start (page=0, pass=0) -> SANE_STATUS_GOOD
[+11.18s] DEBUG: scanner.vala:1230: sane_get_parameters () -> SANE_STATUS_GOOD
[+11.18s] DEBUG: scanner.vala:1242: Parameters: format=SANE_FRAME_RGB last_frame=SANE_TRUE bytes_per_line=7392 pixels_per_line=2464 lines=3437 depth=8
[+11.18s] DEBUG: simple-scan.vala:348: Page is 2464 pixels wide, 3437 pixels high, 8 bits per pixel
[+11.21s] DEBUG: simple-scan.vala:282: Getting color profile for device brother4:bus8;dev1
[+11.21s] DEBUG: simple-scan.vala:302: Unable to find colord device brother4:bus8;dev1: property match 'Serial'='sane:brother4:bus8;dev1' does not exist
[+11.31s] DEBUG: ui.vala:2124: Saving state to /home/alexey/.cache/simple-scan/state
答案1
摘自 Brother Linux Support 的索引页http://support.brother.com/g/s/id/linux/en/index.html?c=us_ot&lang=en&comple=on&redirect=on
可以访问扫描仪的常见问题解答页面http://support.brother.com/g/s/id/linux/en/faq_scn.html?c=us_ot&lang=en&redirect=on
要检查 3 件事：
1）http://support.brother.com/g/s/id/linux/en/faq_scn.html?c=us_ot&lang=en&redirect=on#f00107检查 libusb-0.1-4 是否安装..即使联网！使用以下方法安装sudo apt install libusb-0.1-4
2）http://support.brother.com/g/s/id/linux/en/faq_scn.html?c=us_ot&lang=en&redirect=on#f00101将/usr/lib64/下的指定文件复制到/usr/lib/。提示：你的设备是brscan4
所以
sudo sudo cp /usr/lib64/sane/libsane-brother4.so.1.0.7 /usr/lib/sane
sudo cp /usr/lib64/sane/libsane-brother4.so /usr/lib/sane
sudo cp /usr/lib64/sane/libsane-brother4.so.1 /usr/lib/sane
3）如果通过 USB 连接，则需要 udev 规则
如果联网，请在此处检查全部内容http://support.brother.com/g/s/id/linux/en/instruction_scn1b.html?c=us_ot&lang=en&redirect=on
......是的，一切都可以简单得多......