The application I am writing depends on relatively consistent output from the resample function. I need to be able to, as portably as possible. resize. -resize x+20+30 (like the -scale and -sample examples below) converts an input to an output image which has the pixel dimensions of x Hello, I am trying to reduce the resolution of images to 72×72 using convert – resample 72×72 when I do this the image size does get reduced.

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When the pixel cache reaches the memory limit it uses memory mapping. By using our resmaple, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

The image is convolved with a Gaussian operator of the given radius and standard deviation sigma. Perhaps someone else who is more experienced with -resample can comment. The —channel setting can be used to specify the output channel of the result.


This option specifies the format for the log printed when the —debug option is active. Each pixel is replaced by the most frequent color in a circular neighborhood whose width is specified with radius.


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I am no expert on -resample, but found this page and wanted to point you to it. If the x is negative, the offset is measured leftward from the right edge of the screen to the right edge of the image being displayed.

Command-line Tools: Convert @ ImageMagick

Specify the image source using an image index represented by ustarting at zero for the first image, eg: By definition, raster images have a rectangular shape. The quality value results imagemagifk a request for non-lossy compression. It is not necessary to use —clip to activate the mask; —clip is implied by —mask. Follow the text coordinates with a string.

Most portable way to resample image? – ImageMagick

The x offset normally specifies the leftmost column to remove. Resizing will cause drastic changes to an image, and avoiding or minimizing unwanted ‘artifacts’ is of greatest importance.

ImageMagick Examples Preface and Index. This results in a slight color shift as opposed to a color being clipped as we saw earilier. The —colors or —monochrome option is required for this option to take effect. The —colors or —monochrome option, or writing to an image format which requires color reduction, is required for this option to take effect. The point method changes the matte value of the target pixel.


If the —flatten option appears after all of the input images, all images are flattened. The color of the backdrop is specified as the background color. I stripped out the header information, but still I have the same problem.

The degree of darkening or lightening is proportional to the difference between the source color and 0. Screening any color with black leaves the original color unchanged. If you had sample images, this would be even more perfect: Smoothing threshold eliminates noise in the second derivative of the histogram.

This is a convenience option for annotating your image with text.

This operator is useful for animating a dissolve between two images. If the —region option precedes the —draw option, the origin for transformations is the upper left corner of the region.

The default gravity for the —page option is NorthWesti. White is a maximum negative displacement and middle gray is neutral. For example, if you type the following command:

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