Digital ImagingOptimizing JPEG Images in Photoshop CS5 [Workflow #1]

To optimize a JPEG image, do the following, in order. If one of the steps listed is not needed, skip to the next, but do in the order listed. Record your settings for each step...

Prepare your project folder - include the following folders inside: Working Files/Originals and Finished Files.

Download

Download your JPEG images by inserting your camera’s flash drive in your card reader and launching Adobe Bridge, then selecting File / Get Photos from Camera... from the pull-down menu. Put the files in your project folder, inside the Working Files/Originals folder.

Open a JPEG file in Photoshop by right-clicking on it’s thumbnail in Bridge, and selecting Open With / Adobe Photoshop CS5.

Color Profile

The computers in the Mac lab are now set with Adobe RGB (1998) as the default Working Space, and they are also set to convert [sRGB] to the default Working Space, so you can proceed without any further steps. Even so, if your camera has the option of shooting images in the Adobe RGB (1998) color space, you should do so.

On your personal computer, you should set the color space as outlined in the handout Advanced Technique #1: Color Management, Printing & Photoshop CS5. Once you initially set the color working space in Photoshop on your personal computer, you will not have to assign a profile to each image.

Straighten

If the image needs to be straightened, use the Ruler Tool [hold down the Eyedropper icon to get to the Ruler Tool], and draw along a line that should be straight [horizontal or vertical], and then click on Straighten in the tool bar at top. Photoshop CS5 will straighten your image, and it also crops the excess canvas behind the image [due to rotating the image, there is normally excess canvas that needs to be cropped].

Updated January 2012

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Clicking on the Straighten button automatically straightens AND crops excess canvas. To straighten the image without cropping, hold the Option key when you click on the Straighten button.

Crop

If the image needs to be cropped, select the Crop Tool from the Photoshop tool box and also set Caps Lock [Caps Lock gives you a hairline cursor for more accuracy in cropping]. Use the hairline to select the final image; you can use the control handles to make fine adjustments. When you have the crop set, select Enter on the keyboard.

For this class, since we want a standardized size for our images, type in your default image size [10 in x ____ in] in the palette at the top of the image [above], and then, when using the Crop Tool, the crop area is constrained to the appropriate dimensions/proportions. If you use this method, skip Size [next].

Size

Once the image is straightened and cropped [if needed], set the appropriate size and resolution. In the pull-down menu, select Image / Image Size. To change the pixel dimensions after cropping, or when preparing an image for the web, click on Resample Image [and ensure that Constrain Proportions is also checked].

Unless otherwise specified, set the [largest] image dimension to 10” [width or height], depending on orientation. Ensure that Resample Image is unchecked, and that Constrain Proportions is checked.

Adjust Levels [If your image(s) need to be color corrected, skip this step, and proceed to the Adjust Color instructions]

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In the Photoshop pull-down menu, select Layer / New Adjustment Layer / Levels... Click OK to create a new Levels adjustment layer. In the tool palette to the right of the image, you will see a Levels dialogue box like the following:

The Levels Adjustment dialogue box [circled] is the primary Photoshop tool for adjusting exposure. The graph, or histogram, represents the detail captured by the camera. The slider to the left controls shadow/black details, the middle slider controls mid-tones, and the right slider controls highlights/white. Adjust the shadow and highlight sliders to the limits of the data recorded, and the mid-tone slider to either open up detail, or to darken the overall detail. My settings for this image were 0 / 1.16 / 207. Record your settings.

Using Adjustment Layers allows you to make the necessary Levels adjustments on a [mask] layer above the original [e.g., non-destructive editing]. You can then come back later and re-adjust, or even turn the layer visibility off to view the original image as it appeared before any adjustments were made.

[Curves is the tool to choose when you need more control of the adjustments than the Shadows, Midtones and Highlights adjustments of Levels permit. Curves adjustments allow for multiple numbers of points of adjustment - up to 14 points, as opposed to the 3 points of Levels.]

If you shoot a number of images under the same conditions, adjust Levels on the first image, and then you can save your settings to apply to subsequent images. Once you are finished with your Levels Adjustment, go to Save Levels Preset... in the Adjustments palette to the right of the image. Give your preset a distinctive name. To load the Levels Preset, select Load Levels Preset... in the Adjustments palette.

[For problematic images with large areas in shadow, or where the highlights are overly bright, try the Shadows/Highlights adjustment. First convert the Background layer to a Smart Object [for non-destructive editing] by selecting Filter / Convert for Smart Filters, and then selecting Image / Adjustments / Shadows/Highlights...]

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Adjust Color

In most cases, adjusting Levels will also correct minor color casts. However, if your image needs exposure [Levels] and color correction, it’s best to do these adjustments together in one of the following processes: 1. Layer / New Adjustment Layer / Levels... - This is the method I recommend for [most] images that need color correction. It is similar to the Levels adjustments for exposure, but you adjust the Red, Green and Blue channels separately. If you use this method, skip the initial Levels adjustment.

2. Set Gray Point - Add a new, blank layer above the Background layer. Fill the new layer with 50% gray - Edit / Fill... / Use 50% Gray. Set the Layer Blend Mode to Difference. Next, click on the Threshold icon in the Adjustments panel to the right of the image. Push the slider all the way to the left; your image will turn completely white. Now, slowly push the slider back to the right, until you see “clumps” of black. Using the Color Sampler Tool in the Photoshop tool palette to the left of the image [hold down the Eyedropper Tool to get the Color Sampler Tool], click on one of the areas of black. Turn off or delete the layer containing the gray fill and the Threshold Adjustment Layer, and click on the Levels Adjustment Layer icon. Use the midtone [gray] eyedropper, and click on the color sample reference point. If you use this method, skip the initial Levels adjustment.

3. Gray Card - Shoot your images with a gray card in one of the first shots. Make sure the gray card is in the same lighting as your subject, and is not in a shadow cast by the subject. In Photoshop, select Layer / New Adjustment Layer / Levels... Use the midtone [gray] eyedropper and click on the gray card. In most cases this will set the exposure and color balance. If you use this method, skip the initial Levels adjustment.

4. Layer / New Adjustment Layer / Color Balance... - The basic principle is to add the opposite of the color you are correcting. If your image is too yellow [from artificial lighting, for instance], add it’s opposite, blue. If your image is too blue [shot outdoors in the shade on an overcast day, for example], add it’s opposite, yellow. If your image has a red cast, add it’s opposite, cyan. If you use this method, you will need to adjust Levels first.

Spot

Most spotting and touch-up will be done with the Spot Healing Brush Tool. Since we are doing non-destructive editing, we will first use the Layer Palette to create a new layer. Name the layer Spotting. Ensure that the Spotting layer is between the original image and any adjustment layers.

Select the Spot Healing Brush Tool in the tool palette, and ensure that the Content-Aware radio button and Sample All Layers box are checked. Adjust the brush size so that it is a bit larger than the spots. Now, simply spot or paint over imperfections. [The Content-Aware option is new to the Healing Brush Tool in Photoshop CS5, and makes the Spot Healing Brush Tool the option of first choice to fix spots and small imperfections.]

Use the Clone Stamp Tool to correct any large areas of imperfections. Select the Clone Stamp Tool from Photoshop’s tool palette to the left of the image. In an area close to the imperfection, and the same color/texture, etc., hold down the Option key and click once with your mouse. Next, click on the area to fix; the Clone Stamp Tool copies good pixels from the area selected with the Option key and mouse click, and copies over the imperfection.

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Reduce Noise

If you have a JPEG image with a high amount of noise, first use the pull-down menu to select Filter / Convert for Smart Filters. This permits non-destructive noise reduction, sharpening and other edits, similar to an Adjustment Layer that uses a mask above the actual image. [When using any filter, first make the Background layer a Smart Object by selecting Convert for Smart Filters.]

Next, in Photoshop’s pull-down menu, select Filter / Noise / Reduce Noise... In the Basic dialogue box, start with the following settings: Strength: 8; Preserve Details: 30%; Reduce Color Noise: 80%; Sharpen Details: 30%, and ensure that Remove JPEG Artifact is checked.

If your image has large areas of noise, as in night shots, you can click on the Advanced radio button and try removing noise from individual channels.

As with Levels or Curves adjustments, you can save a preset for Reduce Noise. Once you have achieved the desired noise reduction on your first image, click on the disk icon in the Reduce Noise dialogue box. Name your noise reduction preset with a distinctive name, such as Bob’s Noise Reduction Settings [substitute your name]. For subsequent images, just click on the Settings tab in the Reduce Noise dialogue box and select your preset.

Alternatively, you can opt to add a small amount of Gaussian Blur [1.0% to no more than 1.5%].To add the blur to your JPEG image, first convert your Background layer to a Smart Object - Filter / Convert for Smart Filters. Then select Filter / Blur / Gaussian Blur... from Photoshop’s pull-down menu. Start with a setting of 1.0%; increase to no more than 1.5% if necessary.

The best method of removing noise in JPEG images, however, is with third-party plug-ins. I use and recommend Topaz DeNoise 5 noise reduction filter; it comes with profiles for many digital cameras, including most Nikon and Canon digital SLRs.

Smart Sharpen

Sharpening images will be accomplished with Smart Sharpen [Unsharp Mask was the sharpening tool of choice until Photoshop CS5’s Smart Sharpen]. In the pull-down menu, select Filter / Convert for Smart Filters.

Then, select Filter / Sharpen / Smart Sharpen... Ensure that Preview is checked. For most images, you can stay in the Basic dialogue box. For Remove: , select Lens Blur. Also check More Accurate.

Start with a setting of 100% for Amount, and 1.0 for Radius. Slowly increase the settings until you reach the desired level of sharpening. Be careful not to over-sharpen, which can introduce a “halo” effect that is very noticeable.

The Amount setting adjusts the contrast between edge pixels; the higher the number, the more the contrast. The Radius setting determines the number of pixels around the edge pixels that are affected. The higher the value, the more obvious the sharpening. Of the two adjustments, be the most conservative with the Radius setting...

As with Levels or Curves adjustments, you can save a preset for Smart Sharpen. Once you have achieved the desired sharpening on your first image, click on the disk icon in the Smart Sharpen

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Original Image(in this case a scan)

Finished Image(because it is a portrait,

I did not apply sharpening)

dialogue box. Give your sharpening preset a distinctive name, such as Bob’s Sharpening Settings [substitute your name]. For subsequent images, just click on the Settings tab in the Smart Sharpen dialogue box and select your preset.

If you have an image or images with dark areas that contain significant [visible] noise in them, first reduce the noise in the previous step, Reduce Noise. Then, when sharpening, select the Advanced radio button. You can then select the Shadow or Highlight tab to target specific areas.

Save / Save As...

The final step in optimizing the image is to select Save As... and to change the file format to .psd [if you have already done this, Save your file]. Remember to always check the Embed Color Profile: box in the Save As dialogue box. Do not Save the JPEG image; JPEG is a compression format that discards image information each time you save the file, and, JPEGs do not support layers. By not saving the original JPEG, you will also be able to return to the original file if desired or necessary...