Tkdiff is a plain and simple application for file comparison that can be used to compare the matter within two files. It works with plain text documents (in text format), and the TCL ones. The best part is, the tool is easy to use and so, can be handled by any type of user whether beginner or experienced. It's basic purpose is to compare two versions of an image, for example the same object shot in two different moments, a pre-edited photo and its processed version, a sketch and the finished illustration, etc. It can be particularly useful with photo presets (Lightroom presets, Photoshop actions, etc.).
Example Usage • Option Summary
Use the compare program to mathematically and visually annotate the difference between an image and its reconstruction. See Command Line Processing for advice on how to structure your compare command or see below for example usages of the command.
Example Usage
We list a few examples of the compare command here to illustrate its usefulness and ease of use. To get started, lets compare an image to one thats been sharpened:
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The red areas of the difference image emphasizes (highlight) pixels that are affected by the image sharpening, whereas white de-emphasizes (lowlight) pixels that are untouched by the sharpening process.
In addition to the visual interpretation of the difference in an image and its reconstruction, we report a mathematical measure of the difference:
Or, if you just want the red channel distortion, use this command:
Or, if you just want the overall image distortion, use this command:
If the reconstructed image is a subimage of the image, the compare program returns the best match offset. In addition, it returns a similarity image such that an exact match location is completely white and if none of the pixels match, black, otherwise some gray level in-between:
You can find additional examples of using compare in Examples of ImageMagick Usage.
Two images are considered similar if their difference according to the specified metric and fuzz value is 0, with the exception of the normalized cross correlation metric (NCC), where two images are considered similar when their normalized cross correlation is 1. The default metric is NCC.
The compare program returns 2 on error, 0 if the images are similar, or a value between 0 and 1 if they are not similar.
Option Summary
The compare command recognizes these options. Click on an option to get more details about how that option works.
| Option | Description |
|---|---|
| -alpha | on, activate, off, deactivate, set, opaque, copy',transparent, extract, background, or shape the alpha channel |
| -authenticate value | decrypt image with this password |
| -background color | background color |
| -brightness-contrast geometry | improve brightness / contrast of the image |
| -channel type | apply option to select image channels |
| -colorspace type | set image colorspace |
| -compose operator | set image composite operator |
| -crop geometry | crop the image |
| -decipher filename | convert cipher pixels to plain |
| -debug events | display copious debugging information |
| -define format:option | define one or more image format options |
| -density geometry | horizontal and vertical density of the image |
| -depth value | image depth |
| -dissimilarity-threshold value | maximum distortion for (sub)image match (default 0.2) |
| -distort type coefficients | distort image |
| -encipher filename | convert plain pixels to cipher pixels |
| -extract geometry | extract area from image |
| -fuzz distance | colors within this distance are considered equal |
| -gravity type | horizontal and vertical text placement |
| -help | print program options |
| -highlight-color color | emphasize pixel differences with this color |
| -identify | identify the format and characteristics of the image |
| -interlace type | type of image interlacing scheme |
| -level value | adjust the level of image contrast |
| -limit type value | pixel cache resource limit |
| -log format | format of debugging information |
| -lowlight-color color | de-emphasize pixel differences with this color |
| -metric type | measure differences between images with this metric |
| -negate | replace each pixel with its complementary color |
| -profile filename | add, delete, or apply an image profile |
| -quality value | JPEG/MIFF/PNG compression level |
| -quantize colorspace | reduce image colors in this colorspace |
| -quiet | suppress all warning messages |
| -read-mask filename | associate a read mask with the image |
| -regard-warnings | pay attention to warning messages. |
| -repage geometry | size and location of an image canvas |
| -resize geometry | resize the image |
| -respect-parentheses | settings remain in effect until parenthesis boundary. |
| -rotate degrees | apply Paeth rotation to the image |
| -sampling-factor geometry | horizontal and vertical sampling factor |
| -seed value | seed a new sequence of pseudo-random numbers |
| -separate | separate an image channel into a grayscale image |
| -set attribute value | set an image attribute |
| -sigmoidal-contrast geometry | increase the contrast without saturating highlights or shadows |
| -similarity-threshold value | minimum distortion for (sub)image match (default 0.0) |
| -size geometry | width and height of image |
| -subimage-search | search for subimage |
| -synchronize | synchronize image to storage device |
| -taint | mark the image as modified |
| -transparent-color color | transparent color |
| -trim | trim image edges |
| -verbose | print detailed information about the image |
| -version | print version information |
| -virtual-pixel method | access method for pixels outside the boundaries of the image |
| -read-mask filename | associate a write mask with the image |
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Overloads
| Compare(Image, Image) |
| Compare(Image, Image, ColorDifference) |
| Compare(Image, Image, List<ToleranceRectangle>) |
| Compare(Image, Image, Image) |
| Compare(Image, Image, ColorDifference, Image) |
| Compare(Image, Image, List<ToleranceRectangle>, Image) |
Parameters
- expectedImage
- Image
Returns
- Boolean
Parameters
- expectedImage
- Image
Returns
- Boolean
Applies to
Parameters
- expectedImage
- Image
Returns
- Boolean
Applies to
Parameters
- expectedImage
- Image
Returns
Compare 2 Photo Libraries
- Boolean
Compare 2 Photo Libraries Without
Applies to
Parameters
- expectedImage
- Image
- diffImage
- Image
Returns
- Boolean
Compare(Image, Image, List<ToleranceRectangle>, Image)
Parameters
- expectedImage
- Image
- diffImage
- Image
Returns
- Boolean