问题
I'm having WIA 2.0 problems on Windows 7. On windows XP with wia 2.0 (version from Windows 7 everything works ok)
One device, HP ScanJet 7650 refuses to have its scanning resolution set to anything above 100. When I try to set either of WIA properties
6147 _ Horizontal Resolution
6148 _ Vertical Resolution
to anything above 100 I get:
A first chance exception of type 'System.ArgumentException' occurred
Value does not fall within the expected range.
After that, value of property is 850 (?) and scanner ignores it and scans at 100 dpi
On this same WIA 2.0 and Lexmark X340 MFP I can set scanning resolution without any problems.
Using the same scanner (HP ScanJet 7650) on WIA 1.0 I had no problems. Also, scanning from this scanner using Windows scan applet (from Devices and printers) it can scan in DPIs well above 100. So, I must be doing something wrong.
Here is complete list of properties available on WIA 2.0 for HP ScanJet 7650:
4098 _ Item Name
4099 _ Full Item Name
4101 _ Item Flags
4120 _ Color Profile Name
6154 _ Brightness
6155 _ Contrast
71692 _ Private Highlight Level
71694 _ Private Midtone Level
71693 _ Private Shadow Level
71695 _ Private Gamma
71699 _ Private Saturation
71696 _ Private Hue X
71697 _ Private Hue Y
71698 _ Private Sharpen Level
6159 _ Threshold
6147 _ Horizontal Resolution
6148 _ Vertical Resolution
71687 _ Private Default Resolution
71688 _ Private Quality Resolution
6149 _ Horizontal Start Position
6150 _ Vertical Start Position
6151 _ Horizontal Extent
6152 _ Vertical Extent
4112 _ Pixels Per Line
4113 _ Bytes Per Line
4114 _ Number of Lines
4116 _ Item Size
4118 _ Minimum Buffer Size
6146 _ Current Intent
4103 _ Data Type
4104 _ Bits Per Pixel
4110 _ Bits Per Channel
4109 _ Channels Per Pixel
4111 _ Planar
4107 _ Compression
4108 _ Media Type
4106 _ Format
4105 _ Preferred Format
4123 _ Filename extension
4102 _ Access Rights
6153 _ Photometric Interpretation
71686 _ Private Source Depth
71683 _ Private Preview
71689 _ Private Exposure Method
71722 _ Private Smoothing
71723 _ Private Color Enhanced
71685 _ Private TMA Method
71701 _ Private Defaults
71702 _ 71702
71703 _ 71703
71704 _ 71704
71711 _ 71711
71712 _ 71712
71705 _ 71705
71706 _ 71706
71707 _ 71707
71708 _ 71708
71709 _ 71709
71710 _ 71710
71721 _ 71721
71713 _ 71713
71714 _ 71714
71715 _ 71715
71716 _ 71716
71717 _ 71717
71718 _ 71718
71719 _ 71719
71720 _ Private Property
回答1:
Have you looked at this question?
Try set WiaImageBias.MaximizeQuality
回答2:
The Property Object has two properties, SubTypeMax and SubTypeMin, that you may want to check before setting the value property.
来源:https://stackoverflow.com/questions/3733052/wia-2-0-hp-scanjet-7650-specific-problems