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Image Editing Background and Basics

Chapter Description

In this sample chapter from Adobe Photoshop Elements 2020 Classroom in a Book, author Jeff Carlson begins with an overview of the core concepts behind image correction, and then introduces a range of approachable techniques to help you get more from your photos in just a few clicks.

Recognizing what your photo needs

For some photos, the instant fixes in the Organizer will be enough, but for more control—and access to the full power of Photoshop Elements editing tools—you’ll work in the Editor. Before you explore the Editor’s three working modes, we’ll look at some of the basic concepts behind image adjustment and correction.

Recognizing and understanding a photo’s problems and deficiencies makes the task of correcting and enhancing the image much faster and easier—even when you’re simply choosing from automatic fixes as you did in the full screen view.

  1. In the actions bar above the Media Browser, make sure the Sort By order is set to Oldest. Ctrl-click / Command-click to select both of the photos that you’ve already worked with in this lesson; then add the image DSC_0212.jpg to the selection. Click the Editor button (not the arrow beside it) in the taskbar.

  1. If you’re not already in Expert Edit mode, click Expert in the mode picker at the top of the Editor workspace; then, choose Window > Reset panels.

  1. Click the arrow beside the More button (pse12_morebutton_cmyk.jpg) at the right of the taskbar and choose Histogram from the menu.

  1. If necessary, change the Channel setting in the Histogram panel from the default Colors to RGB; then click the triangular alert icon (24.jpg) at the upper right of the black and white Histogram curve to refresh the histogram graph with uncached information.

    f0102-03.jpg

Understanding the histogram

A histogram is a graph that maps the distribution of tonal values in an image, from the shadows (at the left end of the curve) through the midtones to the highlights (at the right of the curve).

A peak in the curve shows that the corresponding part of the tonal range is well represented—in other words, the image contains plenty of detail in that area. Inversely, a trough in the histogram curve can indicate a deficiency of image detail.

You can use the histogram both as a “diagnostic” tool that can help you recognize where corrections need to be made and also as a source of dynamic feedback that enables you to assess how effective an adjustment will be, even as you set it up.

  1. If you don’t see the Photo Bin at the bottom of the Editor workspace, click the Photo Bin button (pse12_photobin_cmyk.jpg) in the taskbar.

  1. Watch the curve in the Histogram panel as you click each of the thumbnails in the Photo Bin in turn to bring that image to the front in the Edit pane.

  2. For each of the photos you’ve already worked with, click the thumbnail in the Photo Bin to bring the image window to the front; then, choose Enhance > Adjust Smart Fix. Watch the image and its histogram change as you drag the Fix Amount slider to set a value of 60% (for Auto Smart Fix, the value is 40%). Click OK to close the Adjust Smart Fix dialog box.

  3. Bring the image DSC_3607.jpg to the front and choose File > Save As. Name the new file DSC_3607_AutoSmart.jpg, to be saved to the My CIB Work folder and included in the Organizer, but not in a version set. Click Save, then click OK to accept the JPEG quality setting and close the file. Repeat the process for the image DSCN0532.jpg, making sure to add _AutoSmart to the file name.

Adjusting levels

Once you’re familiar with the histogram, the Levels dialog box provides a direct way to adjust the distribution curve in order to improve an image’s tonal range.

  1. You should still have the photo DSC_0212.jpg open from the previous exercise. Choose Enhance > Adjust Lighting > Levels. In the Levels dialog box, make sure the Preview option is activated.

    f0104-01.jpg

In the Levels dialog box, you can use the shadows, midtones, and highlights sliders below the Input Levels histogram graph (left, middle, and right, respectively), or the Set Black Point, Set Gray Point, and Set White Point eyedroppers at the right, to redefine the end points of the curve and adjust the distribution of image information along its length.

Although the midtones range is most in need of adjustment in this image, it’s important to get the shadows and highlights right first.

  1. Select the Set Black Point Eyedropper tool; then, watch the histogram as you click the dark area in the lower-left corner of the image. The white line and gray area in the histogram indicate the shape of the curve prior to this adjustment.

The black point eyedropper has not worked well on our lesson photo; it should ideally be used to sample a black area rather than a colored shadow. The deeper shadows have been “clipped” to black and the color has become much cooler as the warm hues have been removed to produce a pure black at the sampled point.

  1. In the Levels dialog box, click Reset and we’ll try another method for adjusting the shadows. Hold down the Alt / Option key as you drag the shadows slider to the right to set a value of 70, just inside the left end of the tonal curve. The clipping preview shows you where the darkest parts of the image are.

  2. Watch the histogram as you release first the Alt / Option key and then the mouse button. The histogram curve shifts to the left—possibly a little too much. You can see that the left end of the curve has become truncated. In the Levels dialog box, use the shadows slider to reduce the value to 45. The curve in the histogram is adjusted so that there is minimal truncation (clipping).

  3. Hold down the Alt / Option key; then, drag the highlights slider to 185. The clipping preview begins to show significant clipping of image detail in the brighter parts of the photo, as shown in the illustration below. Correct the adjustment by dragging the highlights slider back to 195, where the clipping is minimal; then release the Alt / Option key and the mouse button.

  4. In the Levels controls, drag the midtones slider (the gray triangle below the center of the graph) to the right to set the midtones value to 0.8.

  1. In the Histogram panel, click the yellow alert icon to refresh the display.

    f0106-02.jpg
  2. Compare the original histogram (the red overlay) to the adjusted curve. Information has spread outward, widening the midtones range as well as filling out both the highlights and shadows.

  3. Click OK to close the Levels dialog box. Select Edit > Undo Levels, or press Ctrl+Z / Command+Z, to see how the image looked before editing. Choose Edit > Redo Levels, or Press Ctrl+Y / Command+Y to reinstate your corrections.

  4. Choose File > Save As. Name the new file DSC_0212_Levels.jpg and set your Lessons / My CIB Work folder as the destination. Activate the option Include In The Elements Organizer and disable Save In Version Set With Original. Click Save; then click OK to accept the JPEG settings. Choose File > Close.

Assessing a photo’s color balance

Artificial light, unusual shooting conditions, and incorrect camera settings can all result in unwelcome color casts in an image. Unless your camera is properly set up to compensate for current weather conditions, photos shot on an overcast day may have a flat, bluish cast due to a deficiency in the warmer colors, while the “golden” light of late-afternoon sunshine can produce an overly warm appearance. Fluorescent lighting is notorious for producing a dull, greenish tint.

In this exercise, you’ll work with an image that has the opposite problem: a warm yellow-red cast commonly seen in indoor shots captured under tungsten lighting. We’ll start with a look at the Balance controls in the Quick Edit mode.

  1. To switch to Quick Edit mode, click Quick in the view picker above the editing pane. In Quick Edit mode, choose Window > Reset panels.

  2. Choose File > Open. Navigate to your Lesson 4 folder; then, select the image DSC_0241.jpg, and click Open.

  3. In the Adjustments panel at the right of the Quick Edit workspace, expand the Balance panel. Color imbalances are defined in terms of an image’s temperature and tint; the Balance panel has a separate control pane for adjusting each of these attributes. For now, make sure that the Temperature tab is selected just below the panel’s header.

    f0107-01.jpg

The grid of preview thumbnails shows the full range of variation possible with this control. Clicking the central thumbnail resets an image to its original state—a blue frame highlights the currently selected setting.

  1. Move the pointer over each preview thumbnail in the grid in turn to see that level of adjustment applied temporarily to the image in the work area. A white frame highlights the setting currently previewed.

  1. Click the Tint tab above the slider control and explore the variations.

Working with the Temperature and Tint settings

If you’re new to color correction, the preview thumbnails provide a useful visual reference for understanding what’s behind an unwanted color cast. Before we take a closer look at the issue in the Expert Edit mode, you can correct this photo using the Balance controls and save the results for comparison to other techniques.

  1. In the Temperature pane, click the preview to the left of the central thumbnail.

    f0108-01.jpg
  1. Switch to the Tint pane. Move the pointer over the preview to the right of the central thumbnail. For the Tint controls, moving by one preview in this direction increases the value by an increment of 25—a little too far for our lesson photo. Instead, drag the slider to set a value of 2, or click the number itself and type a new value of 2.

  2. Choose File > Save As. Activate the option Save As A Copy. Name the copy DSC_0241_QuickBalance.jpg, to be saved to your My CIB Work folder and included in the Organizer but not in a version set; then, click Save. Click OK to accept the default JPEG quality settings.

  3. In the Adjustments panel header, click the Reset Image button to reset all the controls, reverting the image to its original state.

    f0108-02.jpg

Consulting the color histogram

Let’s see what the histogram has to say about this photo.

  1. Click Expert in the mode picker at the top of the Editor workspace.

  2. If the Histogram panel is not already open, choose Window > Histogram. If necessary, set the Channel menu at the top of the Histogram panel to Colors.

    f0108-03.jpg

The histogram corroborates the visual evidence: this photo has a serious imbalance in the spread of color information. Rather than a largely unified curve, there is a marked separation of colors; reds and yellows are over-represented in the upper midtones and highlights, while greens and blues are lacking.

In the next exercise, you’ll learn how to correct a color cast by adjusting the photo’s white balance—or redefining the white point—to re-calibrate the image’s color.

Adjusting the white balance

A color cast has the appearance of a tinted transparency overlaid on all the colors in your photograph. For example, the yellow-red cast commonly associated with indoor shots captured under tungsten lighting will be visible even on objects that should appear white, and even white paper photographed under fluorescent lighting will have a blue-green tint.

To adjust the white point, or white balance, you need to identify what should be a neutral tone in your photo—either a white object or an area of gray that should appear neither noticeably cool nor warm. Photoshop Elements will then recalculate the color values across the entire image in relation to whatever pixels you’ve defined as the new, color-neutral benchmark.

  1. Choose Enhance > Adjust Color > Remove Color Cast. The Remove Color Cast dialog box appears, and the pointer becomes an eyedropper cursor (pse11_eyedropper.jpg).

    f0109-01.jpg
  2. Click with the eyedropper to sample a mid-gray from the mortar between the bricks in the background. If this introduces an overly cool blue cast, click the Reset button in the Remove Color Cast dialog box and try again. Try targeting a lighter tone.

  3. When you’re satisfied with the results, click OK to close the Remove Color Cast dialog box.

  4. Examine the color histogram. The histogram curve is much more balanced, though the photo could still be improved. For now, save the corrected image as DSC_0241_WhiteBalance.jpg, with all the usual settings; then, close the file.

4. Making easy color and lighting adjustments | Next Section Previous Section

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