How can I transform HSV to RGB?

Question

Can you help me how can i change HSV to RGB ?

Average out the HSV of pixel and slider, adding them could give a value out of range. Also, post some code. — pointerless, May 18 '17 at 13:20
Yeah, I will write some code, but I need an algorithm what my code should do :( — hidell, May 18 '17 at 13:22
Ok, look [here](http://amin-ahmadi.com/2016/06/05/change-hue-image-qt/) and maybe [here](http://stackoverflow.com/questions/9936021/shifting-the-hue-of-a-qimage-qpixmap) — pointerless, May 18 '17 at 13:23
That: http://stackoverflow.com/questions/44053541/how-can-i-change-hue-saturation-and-value-of-image — hidell, May 18 '17 at 16:50

ΦXocę 웃 Пepeúpa ツ · Answer 1 · 2017-05-18T13:38:40.740

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Your color object is probably has setters for the HSV members....

So you need to define the 3 slider to play with the H,S and V values..

remember:

Hue : the color type (red, blue, or yellow) Ranges from 0 to 360°
Saturation : the intensity of the color. Ranges from 0 to 100%
Brightness (or Value) : the brightness of the color. Ranges from 0 to 100%

QImage myImage = ....
QColor myColor = myImage.pixelColor(...);
myColor.setHsv(....);

edited May 18 '17 at 13:38

answered May 18 '17 at 13:27

ΦXocę 웃 Пepeúpa ツ

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Yeah I have 3 sliders: H - with range 0-360 , S - with range 0-100 , V - with range 0-100 – hidell May 18 '17 at 13:32
But what I should do next? I load image from file as QImage – hidell May 18 '17 at 13:33
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QImage myImage = .... QColor myColor = myImage.pixelColor(...); myColor.setHsv(....); – ΦXocę 웃 Пepeúpa ツ May 18 '17 at 13:38
Convert the QRgb values given by imagevar.pixel(pixx, pixy) to HSV, average them with your slider values, revert those values to QRgb variable, use imagevar.setPixe(pixx,pixy, newQRgb) to change those values. *Edit* exactly as @ΦXocę웃Пepeúpaツ says – pointerless May 18 '17 at 13:40
Please check my answer :) Thanks – hidell May 18 '17 at 14:14

score 0 · Answer 2 · answered May 18 '17 at 13:38

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You mean you want to shift HS and V over the whole image by a value? Easy enough, centre your sliders at 0 and allow hue to go from -2PI to 2PI, and s and v to go from -1.0 to 1.0. Hue can't go out of range, it wraps to +/- PI or whatever convention you use. S and V are clamped to 0 - 1, (or 0 - 255 if you use bytes instead of floats).

You will need HSVtoRGB and RGBtoHSV, which is readily available on the web.

answered May 18 '17 at 13:38

Malcolm McLean

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Please check my answer :) Thanks – hidell May 18 '17 at 14:14

How can I transform HSV to RGB?

2 Answers2