Image - Colorize

Adjusts hue and saturation while keeping intensity the same in RGB or RGBa images. The resultant effect will appear to apply the designated color to a grayscale version of the image.

 

Preset

Choose color to apply by name from a list.

Apply

Apply the RGB settings for the effect in the preset box to the slider bars and RGB values.

Save As…

Save current RGB setting as a preset color.

Delete

Delete previously-saved preset color or disable factory preset.

Red

Colorize value for Red channel.

Green

Colorize value for Green channel.

Blue

Colorize value for Blue channel.

Preview

Check to see effect in action.

 

Preset colors allow choice of a standard range of named colors, as well as saving one's own colors as presets. Because there are many presets and because at times very large images may be manipulated in Manifold, choosing a preset does not apply that preset's color values to the slider bars until the Apply button is pressed. This makes it possible to browse the presets without applying the color values to the main image regardless of whether the Preview box is checked or not.

 

images\sc_colorize01.gif images\sc_colorize02.gif

 

The selected area of the image (shown using Border selection style) has been colorized with the Dark Orchid preset color.

 

Colorize is often used to add color tones to gray scale images. The image should first be converted to an RGB image using Edit - Convert to if it is not already an RGB image.

 

images\img_colorize_eg01.gif

 

Suppose we wish to colorize a circular region in this overhead view of downtown Palo Alto near the 525 University Avenue office building. First, we select the circular region (shown using Border selection style). If we did not select a region the colorize effect would be applied to the entire image.

 

images\img_colorize_eg02.gif

 

We click the preview box and move the Green slider to the right to increase green values and the Red and Blue sliders to the left to decrease red and blue values. The result is colorization into green tones.

 

images\img_colorize_eg03.gif

 

The final result is a convenient means of highlighting a particular region within an image.

 

images\img_colorize_eg04.gif

 

A more sophisticated effect may be achieved by choosing Edit - Select Inverse to select all the pixels not in the original circle, and to then use the Brightness / Contrast control to increase brightness while decreasing contrast slightly. This will "wash out" the rest of the image and make the round green region stand out even more.

 

Colorize and All-Black Images

 

Because colorize keeps intensity the same attempting to colorize an all-black image will result in no change. Black is zero intensity for all color channels. To use colorize to change the color of a solid color layer it must be some visible shade of gray or white.