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Looks like it is fairly straight forward to get an RGB image’s white pixels via the Photoshop document’s histogram property, which is an array of 256 values. So if you export to a PNG using this setting—note I have all Options unchecked:
Then run this Photoshop script on the exportd PNG doc:
app.preferences.rulerUnits = Units.PIXELS;
var d = app.activeDocument;
//the doc‘s total pixels
var t = d.height* d.width;
//the count of pixels in the histogram array‘s 255 index (white pixels)
var w = d.histogram[255];
alert("White Pixel Percentage = " + (w/t)*100);
The result:
Could all the white pixels be counted and compared to all the colored pixels
Hi @PensacolaChri30005758izls , I did take your request literally—assuming you really did want to count all white pixels. If you are looking for "white space" as a design aesthetic then obviously the meaning is quite subjective. For text one might define white space literally as I did above, or everthing but the text block (however you want to define that).
Via an InDesign script you might temporarily apply an Underline or StrikeThrough to all text, before exporting the PNG to Photoshop for checking the histogram. For example:
After an Underline script:
Or
The Photshop histogram returns 43% "white space"
Or 59.9%
I appreciate your taking the request literally, since objectively pixel counting is the only method I can think of to solve the problem (which is subjective) at hand. Your examples are great, Rob Day! I have been experimenting with other tools and they have all failed so far. The histogram box intrigues me the most. If I can count the different colors of pixels of all the text and all the images and all the blank pages, perhaps I could develop my ratio. (text% / image% / whole page 100%)
The ExtendScript histogram object is an array of 256 numbers, which are the pixel count of each gray level in the image. You can loop through the array and get the pixel counts that are greater than 0. This PNG was exported with anti-aliasing turned off so there are only 4 colors. Get a list of levels with more than 0 pixels:
var h = app.activeDocument.histogram;
var s = "Levels with a pixel count greater than 0: \r"
for (var i = 0; i < h.length; i++){
if (h[i] > 0) {
s += "Level: " + i + " " +h[i] + " pixels\r"
}
};
alert(s)
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