applyColorMap
功能
转化为热力图，因为热力图我们看的变化更加细微，在很多地方都用到了热力图。
最近在看CAM，所以记一记这个函数。
感觉还是很有用的。
代码
>>> import cv2 as cv
>>> import numpy as np
>>> img = cv.imread("./res.jpg")
>>> color_zero = np.zeros(shape = img.shape).astype(np.uint8)
>>> color_zero[0:50,0:50,:] = 254
>>> color_img = color_zero
>>> color_gray = cv.cvtColor(color_img,cv.COLOR_BGR2GRAY)
>>> color_app = cv.applyColorMap(color_gray,2)
>>> out = cv.addWeighted(img,0.5,color_app,0.5,0)
>>> cv.imwrite("out.jpg",out)
True
一般需要img为灰度图，然后根据灰度图亮度的大小转化为热力图。
函数参数
| Enumerator | |
|---|---|
| COLORMAP_AUTUMN Python: cv.COLORMAP_AUTUMN |  autumn |
| COLORMAP_BONE Python: cv.COLORMAP_BONE |  bone |
| COLORMAP_JET Python: cv.COLORMAP_JET |  jet |
| COLORMAP_WINTER Python: cv.COLORMAP_WINTER |  winter |
| COLORMAP_RAINBOW Python: cv.COLORMAP_RAINBOW |  rainbow |
| COLORMAP_OCEAN Python: cv.COLORMAP_OCEAN |  ocean |
| COLORMAP_SUMMER Python: cv.COLORMAP_SUMMER |  summer |
| COLORMAP_SPRING Python: cv.COLORMAP_SPRING |  spring |
| COLORMAP_COOL Python: cv.COLORMAP_COOL |  cool |
| COLORMAP_HSV Python: cv.COLORMAP_HSV |  HSV |
| COLORMAP_PINK Python: cv.COLORMAP_PINK |  pink |
| COLORMAP_HOT Python: cv.COLORMAP_HOT |  hot |
| COLORMAP_PARULA Python: cv.COLORMAP_PARULA |  parula |
| COLORMAP_MAGMA Python: cv.COLORMAP_MAGMA |  magma |
| COLORMAP_INFERNO Python: cv.COLORMAP_INFERNO |  inferno |
| COLORMAP_PLASMA Python: cv.COLORMAP_PLASMA |  plasma |
| COLORMAP_VIRIDIS Python: cv.COLORMAP_VIRIDIS |  viridis |
| COLORMAP_CIVIDIS Python: cv.COLORMAP_CIVIDIS |  cividis |
| COLORMAP_TWILIGHT Python: cv.COLORMAP_TWILIGHT |  twilight |
| COLORMAP_TWILIGHT_SHIFTED Python: cv.COLORMAP_TWILIGHT_SHIFTED |  twilight shifted |
官网API
| Python: | |||||
|---|---|---|---|---|---|
| dst | = | cv.applyColorMap( | src, colormap[, dst] | ) | |
| dst | = | cv.applyColorMap( | src, userColor[, dst] | ) |
Parameters
| src | The source image, grayscale or colored of type CV_8UC1 or CV_8UC3. |
|---|---|
| dst | The result is the colormapped source image. Note: Mat::create is called on dst. |
| userColor | The colormap to apply of type CV_8UC1 or CV_8UC3 and size 256 |
| Python: | |||||
|---|---|---|---|---|---|
| dst | = | cv.applyColorMap( | src, colormap[, dst] | ) | |
| dst | = | cv.applyColorMap( | src, userColor[, dst] | ) |
Parameters
| src | The source image, grayscale or colored of type CV_8UC1 or CV_8UC3. |
|---|---|
| dst | The result is the colormapped source image. Note: Mat::create is called on dst. |
| colormap | The colormap to apply, see ColormapTypes |