Nikon 9235 Reference Manual - Page 66

Step 1-Viewing the Histogram, ows to the right.

Get Nikon 9235 - Coolscan III PDF manuals and user guides
UPC - 018208092352
View all Nikon 9235 manuals
Add to My Manuals
Save this manual to your list of manuals

Page 66 highlights

Step 1-Viewing the Histogram The first step in adjusting tone levels and color balance in the Curves palette is to view the histogram displayed in the background of the curve edit display. The histogram provides information on what tones are present in the image and in what amounts, information that you will use when editing curves to make the most of the tone range in the original image. By studying the histogram, you can determine the distribution of tones within the image. The histogram takes the form of a bar graph. The horizontal axis shows the tone level (pixel brightness) as a value from 0 to 255, with the minimum possible value for colors in the selected channel at the left end of the axis and the maximum value to the right (if the selected color model is RGB, calibrated RGB, or grayscale, shadows are to the left and highlights to the right, while when CMYK is selected highlights are to the left and shadows to the right). The vertical axis gives the number of pixels of each tone level found in the image, scaled to fit in the curve edit display. The histogram bears no relation to the position of the individual pixels within the image. To view the distribution of tones in the final, output image after changes to curves, click the histogram button ( ). Click again to view the distribution of tones in the original image. Although values for input and output in the Curves window range from zero to 255 (eight-bit precision, familiar to users of other image editing software), the results of any changes to curves are calculated at a precision of sixteen bits. This makes it possible to modify images scanned at bit depths of twelve and fourteen bits without lowering the quality of the output. Reference:The Tool Chest 65

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
  • 130
  • 131
  • 132
  • 133
  • 134
  • 135
  • 136
  • 137
  • 138
  • 139
  • 140
  • 141
  • 142
  • 143
  • 144
  • 145
  • 146
  • 147
  • 148
  • 149
  • 150
  • 151
  • 152
  • 153
65
Step 1—Viewing the Histogram
The first step in adjusting tone levels and color balance in the
Curves palette is to view the histogram displayed in the back-
ground of the curve edit display.
The histogram provides infor-
mation on what tones are present in the image and in what
amounts, information that you will use when editing curves to
make the most of the tone range in the original image.
By studying
the histogram, you can determine the distribution of tones within
the image.
Reference:The Tool Chest
The histogram takes the form of a bar graph.
The horizontal
axis shows the tone level (pixel brightness) as a value from 0 to
255, with the minimum possible value for colors in the selected
channel at the left end of the axis and the maximum value to the
right (if the selected color model is RGB, calibrated RGB, or
grayscale, shadows are to the left and highlights to the right,
while when CMYK is selected highlights are to the left and shad-
ows to the right).
The vertical axis gives the number of pixels of
each tone level found in the image, scaled to fit in the curve edit
display.
The histogram bears no relation to the position of the
individual pixels within the image.
To view the distribution of tones in the final, output image after
changes to curves, click the histogram button (
).
Click again
to view the distribution of tones in the original image.
Although values for input and output in the Curves window
range from zero to 255 (eight-bit precision, familiar to users of
other image editing software), the results of any changes to curves
are calculated at a precision of sixteen bits.
This makes it pos-
sible to modify images scanned at bit depths of twelve and four-
teen bits without lowering the quality of the output.