Adobe photoshop cs2 User Manual
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ADOBE PHOTOSHOP CS2
User Guide
3
If you chose Exposure And Gamma, move the Exposure and Gain sliders to adjust the brightness and contrast of
the image preview.
4
Click OK.
You can also adjust the preview of an HDR image open in Photoshop by clicking the triangle in the status bar of the
document window and choosing 32-Bit Exposure from the pop-up menu. Move the slider to set the white point for
document window and choosing 32-Bit Exposure from the pop-up menu. Move the slider to set the white point for
viewing the HDR image. Since the adjustment is made per view, you can have the same HDR image open in multiple
windows, each with a different preview adjustment. Preview adjustments made with this method are not stored in the
HDR image file.
windows, each with a different preview adjustment. Preview adjustments made with this method are not stored in the
HDR image file.
See also
To convert from 32 bits to 8 or 16 bits per channel
HDR images contain luminance levels that far exceed the luminance data that can be stored in 8- or 16-bits-per-
channel image files. Photoshop lets you make exposure and contrast corrections so that converting a 32-bits-per-
channel HDR image to 8 or 16 bits per channel results in an image with the dynamic range (tonal range) you want.
channel image files. Photoshop lets you make exposure and contrast corrections so that converting a 32-bits-per-
channel HDR image to 8 or 16 bits per channel results in an image with the dynamic range (tonal range) you want.
1
Open a 32-bits-per-channel image and choose Image > Mode > 16 Bits/Channel or 8 Bits/Channel.
2
In the HDR Conversion dialog box, choose a method for adjusting the brightness and contrast in the image:
Exposure And Gamma
Lets you manually adjust the brightness and contrast of the HDR image.
Highlight Compression
Compresses the highlight values in the HDR image so they fall within the luminance values
range of the 8- or 16-bits-per-channel image file. No further adjustments are necessary; this method is automatic.
Click OK to convert the 32-bits-per-channel image.
Click OK to convert the 32-bits-per-channel image.
Equalize Histogram
Compresses the dynamic range of the HDR image while trying to preserve some contrast. No
further adjustments are necessary; this method is automatic. Click OK to convert the 32-bits-per-channel image.
Local Adaptation
Adjusts the tonality in the HDR image by calculating the amount of correction necessary for local
brightness regions throughout the image.
3
(Optional) Click the arrow to display the toning curve and histogram. The histogram shows the luminance values
in the original HDR image. The red tick marks along the horizontal axis are in 1 EV (approximately 1 f-stop) incre
ments. The toning curve is active only for the Local Adaptation method.
ments. The toning curve is active only for the Local Adaptation method.
4
Do any of the following:
•
If you chose Exposure And Gamma, move the Exposure slider to adjust the gain and move the Gamma slider to
adjust the contrast.
adjust the contrast.
•
If you chose Local Adaptation, move the Radius slider to specify the size of the local brightness regions. Move the
Threshold slider to specify how far apart two pixels’ tonal values must be before they’re no longer part of the same
brightness region. You can also use the toning curve to make adjustments.
Threshold slider to specify how far apart two pixels’ tonal values must be before they’re no longer part of the same
brightness region. You can also use the toning curve to make adjustments.
Note: The toning curve usually lets you make limited changes from point to point and attempts to equalize your changes
across the points. If you select the Corner option after inserting a point on the curve, the limit is removed and no equal
ization is performed when you insert and move a second point. You’ll notice that the curve becomes angular at a point
with the Corner option applied.
across the points. If you select the Corner option after inserting a point on the curve, the limit is removed and no equal
ization is performed when you insert and move a second point. You’ll notice that the curve becomes angular at a point
with the Corner option applied.