I've coded a simple get_dof based focus stacking script, which works nicely for me.
I then enable TV bracketing in CHDK, take 5 shots, and get a permuted sequence of images.
My plan was to use a simple perl script and Image::ExifTool to
deduce the HDR sets, and send them on to enfuse for combining. I will then use CombineZP under Wine
to focus stack them.
But the Exif doesn't appear to contain the focus distance, which was to be a key parameter
in the HDR-set grouping.
I'm using a A630. Is the focus distance actually present? I've looked pretty carefully, and I can't see it.
I've dumped the Exif from two successive images using exiftool -S, and diff'd them, and it doesn't look good;
(sample exif, and the diff output appended)
BugBear
2c2
< FileName: IMG_0253.JPG
---
> FileName: IMG_0254.JPG
4,7c4,7
< FileSize: 2.6 MB
< FileModifyDate: 2016:07:13 19:26:52+01:00
< FileAccessDate: 2016:07:14 09:24:00+01:00
< FileInodeChangeDate: 2016:07:14 09:22:55+01:00
---
> FileSize: 1392 kB
> FileModifyDate: 2016:07:13 19:27:00+01:00
> FileAccessDate: 2016:07:14 09:24:01+01:00
> FileInodeChangeDate: 2016:07:14 09:22:58+01:00
18c18
< ModifyDate: 2016:07:13 19:22:26
---
> ModifyDate: 2016:07:13 19:22:28
20c20
< ExposureTime: 1/5
---
> ExposureTime: 0.6
23,24c23,24
< DateTimeOriginal: 2016:07:13 19:22:26
< CreateDate: 2016:07:13 19:22:26
---
> DateTimeOriginal: 2016:07:13 19:22:28
> CreateDate: 2016:07:13 19:22:28
27c27
< ShutterSpeedValue: 1/5
---
> ShutterSpeedValue: 0.6
69c69
< TargetExposureTime: 1/5
---
> TargetExposureTime: 0.6
90c90
< FileNumber: 100-0253
---
> FileNumber: 100-0254
94c94
< CameraTemperature: 27 C
---
> CameraTemperature: 28 C
114c114
< ImageUniqueID: 9ddf9e7c38ede378640ccbafc1e9297f
---
> ImageUniqueID: 9adf907c38ede378640ccbafc1e9297f
135c135
< ThumbnailLength: 5790
---
> ThumbnailLength: 4294
149,150c149,150
< ShutterSpeed: 1/5
< ThumbnailImage: (Binary data 5790 bytes, use -b option to extract)
---
> ShutterSpeed: 0.6
> ThumbnailImage: (Binary data 4294 bytes, use -b option to extract)
156c156
< LightValue: 6.7
---
> LightValue: 5.2
ExifToolVersion: 9.46
FileName: IMG_0253.JPG
Directory: .
FileSize: 2.6 MB
FileModifyDate: 2016:07:13 19:26:52+01:00
FileAccessDate: 2016:07:14 09:24:00+01:00
FileInodeChangeDate: 2016:07:14 09:22:55+01:00
FilePermissions: rw-r--r--
FileType: JPEG
MIMEType: image/jpeg
ExifByteOrder: Little-endian (Intel, II)
Make: Canon
Model: Canon PowerShot A630
Orientation: Horizontal (normal)
XResolution: 180
YResolution: 180
ResolutionUnit: inches
ModifyDate: 2016:07:13 19:22:26
YCbCrPositioning: Centered
ExposureTime: 1/5
FNumber: 4.0
ExifVersion: 0220
DateTimeOriginal: 2016:07:13 19:22:26
CreateDate: 2016:07:13 19:22:26
ComponentsConfiguration: Y, Cb, Cr, -
CompressedBitsPerPixel: 5
ShutterSpeedValue: 1/5
ApertureValue: 4.0
MaxApertureValue: 3.5
Flash: Off, Did not fire
FocalLength: 17.3 mm
MacroMode: Normal
SelfTimer: 2 s, Custom
Quality: Superfine
CanonFlashMode: Off
ContinuousDrive: Single
FocusMode: Manual Focus (3)
RecordMode: JPEG
CanonImageSize: Large
EasyMode: Manual
DigitalZoom: None
Contrast: Normal
Saturation: Normal
Sharpness: 0
CameraISO: 80
MeteringMode: Evaluative
FocusRange: Manual
CanonExposureMode: Manual
LensType: Unknown (-1)
MaxFocalLength: 29.2 mm
MinFocalLength: 7.3 mm
FocalUnits: 1000/mm
MaxAperture: 3.6
MinAperture: 8
FlashBits: (none)
FocusContinuous: Manual
AESetting: Normal AE
ZoomSourceWidth: 3264
ZoomTargetWidth: 3264
SpotMeteringMode: Center
ManualFlashOutput: n/a
FocalType: Zoom
FocalPlaneXSize: 7.44 mm
FocalPlaneYSize: 5.59 mm
AutoISO: 100
BaseISO: 79
MeasuredEV: 8.38
TargetAperture: 4
TargetExposureTime: 1/5
ExposureCompensation: 0
WhiteBalance: Tungsten
SlowShutter: Off
SequenceNumber: 0
OpticalZoomCode: 6
FlashGuideNumber: 0
FlashExposureComp: 0
AutoExposureBracketing: Off
AEBBracketValue: 0
ControlMode: Camera Local Control
FocusDistanceUpper: 0.31 m
FocusDistanceLower: 0 m
BulbDuration: 0
CameraType: Compact
AutoRotate: None
NDFilter: Off
SelfTimer2: 0
FlashOutput: 0
CanonImageType: IMG:PowerShot A630 JPEG
CanonFirmwareVersion: Firmware Version 1.00
FileNumber: 100-0253
OwnerName:
ISO: 75
Rotation: 0
CameraTemperature: 27 C
CanonModelID: PowerShot A630
AFAreaMode: Off (Manual Focus)
NumAFPoints: 9
ValidAFPoints: 1
CanonImageWidth: 3264
CanonImageHeight: 2448
AFImageWidth: 1088
AFImageHeight: 409
AFAreaWidths: 196 196 196 196 196 196 196 196 196
AFAreaHeights: 74 74 74 74 74 74 74 74 74
AFAreaXPositions: 0 0 0 0 0 0 0 0 0
AFAreaYPositions: 0 0 0 0 0 0 0 0 0
AFPointsInFocus: (none)
PrimaryAFPoint: 0
ThumbnailImageValidArea: 0 0 0 0
DateStampMode: Off
MyColorMode: Off
FirmwareRevision: 1.00 rev 3.00
Categories: (none)
ImageUniqueID: 9ddf9e7c38ede378640ccbafc1e9297f
UserComment:
FlashpixVersion: 0100
ColorSpace: sRGB
ExifImageWidth: 3264
ExifImageHeight: 2448
InteropIndex: R98 - DCF basic file (sRGB)
InteropVersion: 0100
RelatedImageWidth: 3264
RelatedImageHeight: 2448
FocalPlaneXResolution: 11412.58741
FocalPlaneYResolution: 11439.25234
FocalPlaneResolutionUnit: inches
SensingMethod: One-chip color area
FileSource: Digital Camera
CustomRendered: Normal
ExposureMode: Manual
DigitalZoomRatio: 1
SceneCaptureType: Standard
Compression: JPEG (old-style)
ThumbnailOffset: 5120
ThumbnailLength: 5790
ImageWidth: 3264
ImageHeight: 2448
EncodingProcess: Baseline DCT, Huffman coding
BitsPerSample: 8
ColorComponents: 3
YCbCrSubSampling: YCbCr4:2:2 (2 1)
Aperture: 4.0
DriveMode: Self-timer Operation
ImageSize: 3264x2448
Lens: 7.3 - 29.2 mm
LensID: Unknown 7-29mm
ScaleFactor35efl: 4.8
ShootingMode: Manual
ShutterSpeed: 1/5
ThumbnailImage: (Binary data 5790 bytes, use -b option to extract)
CircleOfConfusion: 0.006 mm
FOV: 24.6 deg
FocalLength35efl: 17.3 mm (35 mm equivalent: 82.7 mm)
HyperfocalDistance: 11.93 m
Lens35efl: 7.3 - 29.2 mm (35 mm equivalent: 34.8 - 139.2 mm)
LightValue: 6.7
