I'm getting invalid argument errors when trying to run scanimage > out.pnm using an Epson SX410 printer/scanner unit running sane-backends 1.0.21 on Debian. Here's the debug output:
steffan at debian:~$ scanimage -L device `v4l:/dev/video0' is a Noname Built-in iSight virtual device device `epson2:libusb:001:014' is a Epson PID 0851 flatbed scanner steffan at debian:~$ scanimage --version scanimage (sane-backends) 1.0.21; backend version 1.0.21 steffan at debian:~$ SANE_DEBUG_EPSON2=255 scanimage > out.pnm [sanei_debug] Setting debug level of epson2 to 255. [epson2] sane_epson2_init: sane-backends 1.0.21 [epson2] epson2 backend, version 1.0.124 [epson2] sane_epson2_get_devices [epson2] probe_devices [epson2] free_devices [epson2] attach_one_config: len = 3, line = usb [epson2] attach_one_config: len = 16, line = usb 0x4b8 0x0851 [epson2] attach_one_usb: dev = libusb:001:014 [epson2] attach: devname = libusb:001:014, type = 3 [epson2] e2_dev_init [epson2] open_scanner: libusb:001:014 [epson2] scanner opened [epson2] found valid Epson scanner: 0x4b8/0x851 (vendorID/productID) [epson2] e2_set_model: model is 'generic' [epson2] esci_reset [epson2] e2_cmd_simple: size = 2 [epson2] e2_send: size = 2, reply = 1 [epson2] e2_send: ESC @ [epson2] buf[0] 1b . [epson2] buf[1] 40 @ [epson2] e2_send: cmd count, r = 0, w = 1 [epson2] e2_recv: size = 1, buf = 0x7fff933ced5f [epson2] e2_recv: cmd count, r = 1, w = 1 [epson2] buf[0] 06 . [epson2] e2_discover_capabilities [epson2] esci_request_identity [epson2] e2_cmd_info_block, params len = 2, reply len = 0, buf = 0x7fff933ced48 [epson2] e2_send: size = 2, reply = 0 [epson2] e2_send: ESC I [epson2] buf[0] 1b . [epson2] buf[1] 49 I [epson2] e2_send: cmd count, r = 1, w = 2 [epson2] e2_recv: size = 4, buf = 0x7fff933cec10 [epson2] e2_recv: cmd count, r = 2, w = 2 [epson2] buf[0] 02 . [epson2] buf[1] 02 . [epson2] buf[2] 13 . [epson2] buf[3] 00 . [epson2] e2_recv_info_block: payload length: 19 [epson2] e2_recv: size = 19, buf = 0x9d42b0 [epson2] e2_recv: cmd count, r = 3, w = 2 [epson2] buf[0] 44 D [epson2] buf[1] 37 7 [epson2] buf[2] 52 R [epson2] buf[3] 4b K [epson2] buf[4] 00 . [epson2] buf[5] 52 R [epson2] buf[6] 2c , [epson2] buf[7] 01 . [epson2] buf[8] 52 R [epson2] buf[9] 58 X [epson2] buf[10] 02 . [epson2] buf[11] 52 R [epson2] buf[12] b0 . [epson2] buf[13] 04 . [epson2] buf[14] 41 A [epson2] buf[15] d8 . [epson2] buf[16] 27 ' [epson2] buf[17] d8 . [epson2] buf[18] 36 6 [epson2] e2_set_cmd_level: D7 [epson2] e2_add_resolution: add (dpi): 75 [epson2] e2_add_resolution: add (dpi): 300 [epson2] e2_add_resolution: add (dpi): 600 [epson2] e2_add_resolution: add (dpi): 1200 [epson2] maximum scan area: 10200x14040 [epson2] e2_set_fbf_area: 0.000000,0.000000 215.899994,297.179993 1200 [mm] [epson2] esci_request_status [epson2] e2_send: size = 2, reply = 4 [epson2] e2_send: ESC F [epson2] buf[0] 1b . [epson2] buf[1] 46 F [epson2] e2_send: cmd count, r = 3, w = 3 [epson2] e2_recv: size = 4, buf = 0x7fff933cec60 [epson2] e2_recv: cmd count, r = 4, w = 3 [epson2] buf[0] 02 . [epson2] buf[1] 02 . [epson2] buf[2] 00 . [epson2] buf[3] 00 . [epson2] status: 02 [epson2] ready [epson2] no option equipment installed [epson2] support extended commands [epson2] detection with request_extended_status [epson2] esci_request_extended_status [epson2] e2_cmd_info_block, params len = 2, reply len = 42, buf = 0x7fff933ceca8 [epson2] e2_send: size = 2, reply = 46 [epson2] e2_send: ESC f [epson2] buf[0] 1b . [epson2] buf[1] 66 f [epson2] e2_send: cmd count, r = 4, w = 4 [epson2] e2_recv: size = 4, buf = 0x7fff933cebf0 [epson2] e2_recv: cmd count, r = 5, w = 4 [epson2] buf[0] 02 . [epson2] buf[1] 02 . [epson2] buf[2] 2a * [epson2] buf[3] 00 . [epson2] e2_recv_info_block: payload length: 42 [epson2] e2_recv: size = 42, buf = 0x9d4ba0 [epson2] e2_recv: cmd count, r = 6, w = 4 [epson2] buf[0] 00 . [epson2] buf[1] 00 . [epson2] buf[2] 00 . [epson2] buf[3] 00 . [epson2] buf[4] 00 . [epson2] buf[5] 00 . [epson2] buf[6] 00 . [epson2] buf[7] 00 . [epson2] buf[8] 00 . [epson2] buf[9] 00 . [epson2] buf[10] 00 . [epson2] buf[11] c0 . [epson2] buf[12] d8 . [epson2] buf[13] 27 ' [epson2] buf[14] d8 . [epson2] buf[15] 36 6 [epson2] buf[16] 00 . [epson2] buf[17] 00 . [epson2] buf[18] 00 . [epson2] buf[19] 00 . [epson2] buf[20] 00 . [epson2] buf[21] 00 . [epson2] buf[22] 00 . [epson2] buf[23] 00 . [epson2] buf[24] 00 . [epson2] buf[25] 00 . [epson2] buf[26] 50 P [epson2] buf[27] 49 I [epson2] buf[28] 44 D [epson2] buf[29] 20 [epson2] buf[30] 30 0 [epson2] buf[31] 38 8 [epson2] buf[32] 35 5 [epson2] buf[33] 31 1 [epson2] buf[34] 20 [epson2] buf[35] 20 [epson2] buf[36] 20 [epson2] buf[37] 20 [epson2] buf[38] 20 [epson2] buf[39] 20 [epson2] buf[40] 20 [epson2] buf[41] 20 [epson2] main = 00, ADF = 00, TPU = 00, main 2 = c0 [epson2] e2_set_model: model is 'PID 0851' [epson2] e2_set_fbf_area: 0.000000,0.000000 215.899994,297.179993 1200 [mm] [epson2] no command available to detect capabilities [epson2] esci_request_identity2 [epson2] e2_cmd_info_block, params len = 2, reply len = 0, buf = 0x7fff933ced48 [epson2] e2_send: size = 2, reply = 0 [epson2] e2_send: ESC i [epson2] buf[0] 1b . [epson2] buf[1] 69 i [epson2] e2_send: cmd count, r = 6, w = 5 [epson2] e2_recv: size = 4, buf = 0x7fff933cec00 [epson2] e2_recv: cmd count, r = 7, w = 5 [epson2] buf[0] 02 . [epson2] buf[1] 02 . [epson2] buf[2] 28 ( [epson2] buf[3] 00 . [epson2] e2_recv_info_block: payload length: 40 [epson2] e2_recv: size = 40, buf = 0x9d4be0 [epson2] e2_recv: cmd count, r = 8, w = 5 [epson2] buf[0] b0 . [epson2] buf[1] 04 . [epson2] buf[2] 55 U [epson2] buf[3] 00 . [epson2] buf[4] 00 . [epson2] buf[5] 00 . [epson2] buf[6] 00 . [epson2] buf[7] 00 . [epson2] buf[8] 00 . [epson2] buf[9] 00 . [epson2] buf[10] 00 . [epson2] buf[11] 00 . [epson2] buf[12] 00 . [epson2] buf[13] 00 . [epson2] buf[14] 4b K [epson2] buf[15] 00 . [epson2] buf[16] 96 . [epson2] buf[17] 00 . [epson2] buf[18] 2c , [epson2] buf[19] 01 . [epson2] buf[20] 58 X [epson2] buf[21] 02 . [epson2] buf[22] b0 . [epson2] buf[23] 04 . [epson2] buf[24] 00 . [epson2] buf[25] 00 . [epson2] buf[26] 4b K [epson2] buf[27] 00 . [epson2] buf[28] 96 . [epson2] buf[29] 00 . [epson2] buf[30] 2c , [epson2] buf[31] 01 . [epson2] buf[32] 58 X [epson2] buf[33] 02 . [epson2] buf[34] b0 . [epson2] buf[35] 04 . [epson2] buf[36] 60 ` [epson2] buf[37] 09 . [epson2] buf[38] 00 . [epson2] buf[39] 00 . [epson2] discovering max depth, NAKs are expected [epson2] e2_esc_cmd: cmd = 0x44, val = 16 [epson2] e2_cmd_simple: size = 2 [epson2] e2_send: size = 2, reply = 1 [epson2] e2_send: ESC D [epson2] buf[0] 1b . [epson2] buf[1] 44 D [epson2] e2_send: cmd count, r = 8, w = 6 [epson2] e2_recv: size = 1, buf = 0x7fff933cec8f [epson2] e2_recv: cmd count, r = 9, w = 6 [epson2] buf[0] 06 . [epson2] e2_cmd_simple: size = 1 [epson2] e2_send: size = 1, reply = 1 [epson2] buf[0] 10 . [epson2] e2_send: cmd count, r = 9, w = 7 [epson2] e2_recv: size = 1, buf = 0x7fff933cec8f [epson2] e2_recv: cmd count, r = 10, w = 7 [epson2] buf[0] 15 . [epson2] e2_cmd_simple: NAK [epson2] e2_esc_cmd: cmd = 0x44, val = 14 [epson2] e2_cmd_simple: size = 2 [epson2] e2_send: size = 2, reply = 1 [epson2] e2_send: ESC D [epson2] buf[0] 1b . [epson2] buf[1] 44 D [epson2] e2_send: cmd count, r = 10, w = 8 [epson2] e2_recv: size = 1, buf = 0x7fff933cec8f [epson2] e2_recv: cmd count, r = 11, w = 8 [epson2] buf[0] 06 . [epson2] e2_cmd_simple: size = 1 [epson2] e2_send: size = 1, reply = 1 [epson2] buf[0] 0e . [epson2] e2_send: cmd count, r = 11, w = 9 [epson2] e2_recv: size = 1, buf = 0x7fff933cec8f [epson2] e2_recv: cmd count, r = 12, w = 9 [epson2] buf[0] 15 . [epson2] e2_cmd_simple: NAK [epson2] e2_esc_cmd: cmd = 0x44, val = 12 [epson2] e2_cmd_simple: size = 2 [epson2] e2_send: size = 2, reply = 1 [epson2] e2_send: ESC D [epson2] buf[0] 1b . [epson2] buf[1] 44 D [epson2] e2_send: cmd count, r = 12, w = 10 [epson2] e2_recv: size = 1, buf = 0x7fff933cec8f [epson2] e2_recv: cmd count, r = 13, w = 10 [epson2] buf[0] 06 . [epson2] e2_cmd_simple: size = 1 [epson2] e2_send: size = 1, reply = 1 [epson2] buf[0] 0c . [epson2] e2_send: cmd count, r = 13, w = 11 [epson2] e2_recv: size = 1, buf = 0x7fff933cec8f [epson2] e2_recv: cmd count, r = 14, w = 11 [epson2] buf[0] 15 . [epson2] e2_cmd_simple: NAK [epson2] maximum supported color depth: 8 [epson2] esci_request_focus_position [epson2] setting focus is not supported [epson2] esci_request_scanner_status [epson2] e2_send: size = 2, reply = 16 [epson2] e2_send: FS F [epson2] buf[0] 1c . [epson2] buf[1] 46 F [epson2] e2_send: cmd count, r = 14, w = 12 [epson2] e2_recv: size = 16, buf = 0x7fff933cecf0 [epson2] e2_recv: cmd count, r = 15, w = 12 [epson2] buf[0] 01 . [epson2] buf[1] 00 . [epson2] buf[2] 00 . [epson2] buf[3] c0 . [epson2] buf[4] 00 . [epson2] buf[5] 00 . [epson2] buf[6] 00 . [epson2] buf[7] 00 . [epson2] buf[8] 00 . [epson2] buf[9] 00 . [epson2] buf[10] 00 . [epson2] buf[11] 00 . [epson2] buf[12] 00 . [epson2] buf[13] 00 . [epson2] buf[14] 00 . [epson2] buf[15] 00 . [epson2] global status : 0x01 [epson2] warmup can be cancelled [epson2] adf status : 0x00 [epson2] not installed [epson2] not enabled [epson2] tpu status : 0x00 [epson2] not installed [epson2] not enabled [epson2] device type : 0xc0 [epson2] main body status: 0x00 [epson2] e2_dev_post_init [epson2] CCT model id is 0x98, profile offset 83 [epson2] esci_reset [epson2] e2_cmd_simple: size = 2 [epson2] e2_send: size = 2, reply = 1 [epson2] e2_send: ESC @ [epson2] buf[0] 1b . [epson2] buf[1] 40 @ [epson2] e2_send: cmd count, r = 15, w = 13 [epson2] e2_recv: size = 1, buf = 0x7fff933ced5f [epson2] e2_recv: cmd count, r = 16, w = 13 [epson2] buf[0] 06 . [epson2] scanner model: PID 0851 [epson2] close_scanner: fd = 0 [epson2] esci_request_extended_status [epson2] e2_cmd_info_block, params len = 2, reply len = 42, buf = 0x7fff933cede8 [epson2] e2_send: size = 2, reply = 46 [epson2] e2_send: ESC f [epson2] buf[0] 1b . [epson2] buf[1] 66 f [epson2] e2_send: cmd count, r = 16, w = 14 [epson2] e2_recv: size = 4, buf = 0x7fff933ced30 [epson2] e2_recv: cmd count, r = 17, w = 14 [epson2] buf[0] 02 . [epson2] buf[1] 02 . [epson2] buf[2] 2a * [epson2] buf[3] 00 . [epson2] e2_recv_info_block: payload length: 42 [epson2] e2_recv: size = 42, buf = 0x9d4ba0 [epson2] e2_recv: cmd count, r = 18, w = 14 [epson2] buf[0] 00 . [epson2] buf[1] 00 . [epson2] buf[2] 00 . [epson2] buf[3] 00 . [epson2] buf[4] 00 . [epson2] buf[5] 00 . [epson2] buf[6] 00 . [epson2] buf[7] 00 . [epson2] buf[8] 00 . [epson2] buf[9] 00 . [epson2] buf[10] 00 . [epson2] buf[11] c0 . [epson2] buf[12] d8 . [epson2] buf[13] 27 ' [epson2] buf[14] d8 . [epson2] buf[15] 36 6 [epson2] buf[16] 00 . [epson2] buf[17] 00 . [epson2] buf[18] 00 . [epson2] buf[19] 00 . [epson2] buf[20] 00 . [epson2] buf[21] 00 . [epson2] buf[22] 00 . [epson2] buf[23] 00 . [epson2] buf[24] 00 . [epson2] buf[25] 00 . [epson2] buf[26] 50 P [epson2] buf[27] 49 I [epson2] buf[28] 44 D [epson2] buf[29] 20 [epson2] buf[30] 30 0 [epson2] buf[31] 38 8 [epson2] buf[32] 35 5 [epson2] buf[33] 31 1 [epson2] buf[34] 20 [epson2] buf[35] 20 [epson2] buf[36] 20 [epson2] buf[37] 20 [epson2] buf[38] 20 [epson2] buf[39] 20 [epson2] buf[40] 20 [epson2] buf[41] 20 [epson2] main = 00, ADF = 00, TPU = 00, main 2 = c0 [epson2] sane_epson2_get_devices - results: [epson2] 0 (3): PID 0851 scanimage: sane_start: Invalid argument [epson2] sane_epson2_exit [epson2] free_devices