Image Cropping Using Python
I am new to Python coding and I am writing a program in which I will be cropping an entered image and then saving it in a location. Now, I am being able to do this using a combinat
Solution 1:
I took a quick look and fixed a few other problems along the way. Essentially my changes do this:
- Draw the bounding box on a temporary image, set its alpha transparency, and then blit this over top of the main image.
- Avoid extraneous drawing cycles (when the mouse isn't moving, no sense in drawing the same image again).
- Ensure that width and height are always positive. If the rect is drawn by dragging the mouse left or up, your code would end up with a negative width and/or height, raising an exception when trying to write the final image.
Here is a screenshot of running the fixed code:
I split the code into two parts to avoid the scrollbars:
import pygame, sys
from PIL import Image
pygame.init()
defdisplayImage(screen, px, topleft, prior):
# ensure that the rect always has positive width, height
x, y = topleft
width = pygame.mouse.get_pos()[0] - topleft[0]
height = pygame.mouse.get_pos()[1] - topleft[1]
if width < 0:
x += width
width = abs(width)
if height < 0:
y += height
height = abs(height)
# eliminate redundant drawing cycles (when mouse isn't moving)
current = x, y, width, height
ifnot (width and height):
return current
if current == prior:
return current
# draw transparent box and blit it onto canvas
screen.blit(px, px.get_rect())
im = pygame.Surface((width, height))
im.fill((128, 128, 128))
pygame.draw.rect(im, (32, 32, 32), im.get_rect(), 1)
im.set_alpha(128)
screen.blit(im, (x, y))
pygame.display.flip()
# return current box extentsreturn (x, y, width, height)
And part 2 (concatenate to the above):
def setup(path):
px = pygame.image.load(path)
screen = pygame.display.set_mode( px.get_rect()[2:] )
screen.blit(px, px.get_rect())
pygame.display.flip()
return screen, px
def mainLoop(screen, px):
topleft = bottomright = prior = None
n=0while n!=1:
for event in pygame.event.get():
if event.type == pygame.MOUSEBUTTONUP:
ifnot topleft:
topleft = event.pos
else:
bottomright = event.pos
n=1if topleft:
prior = displayImage(screen, px, topleft, prior)
return ( topleft + bottomright )
if __name__ == "__main__":
input_loc = 'stack.png'
output_loc = 'out.png'
screen, px = setup(input_loc)
left, upper, right, lower = mainLoop(screen, px)
# ensure output rect always has positive width, height
if right < left:
left, right = right, left
iflower < upper:
lower, upper = upper, lower
im = Image.open(input_loc)
im = im.crop(( left, upper, right, lower))
pygame.display.quit()
im.save(output_loc)
Solution 2:
The answer by samplebias was great for me. I extended it for the large images I am working with by adding zoom and pan capabilities.
import pygame, sys
from pygame.localsimport K_a, K_s,K_w,K_d,K_LEFTBRACKET,K_RIGHTBRACKET
from PIL import Image
pygame.init()
BG_COLOR = (0,0,0)
defdisplayRect(screen, px, topleft, prior,pos,scale):
# ensure that the rect always has positive width, height#topleft = [(val-pos[i])/scale for i,val in enumerate(topleft)]
topleft = [(val/scale-pos[i]) for i,val inenumerate(topleft)]
x, y = topleft
bottomright = pygame.mouse.get_pos()
width = bottomright[0] - topleft[0]
height = bottomright[1] - topleft[1]
if width < 0:
x += width
width = abs(width)
if height < 0:
y += height
height = abs(height)
# eliminate redundant drawing cycles (when mouse isn't moving)
current = x, y, width, height
ifnot (width and height):
return current
if current == prior:
return current
# draw transparent box and blit it onto canvas
rect = px.get_rect()
px = pygame.transform.scale(px,[rect.width/scale, rect.height/scale])
screen.blit(px, (rect[0]-pos[0],rect[1]-pos[1]))
im = pygame.Surface((width, height))
im.fill((128, 128, 128))
pygame.draw.rect(im, (32, 32, 32), im.get_rect(), 1)
im.set_alpha(128)
screen.blit(im, (x, y))
pygame.display.flip()
# return current box extentsreturn (x, y, width, height)
defsetup(px):
screen = pygame.display.set_mode( px.get_rect()[2:] )
screen.blit(px, px.get_rect())
pygame.display.flip()
return screen, px
defmove(pos,scale,px,screen):
x,y = pos
#print pos,x
rect = px.get_rect()
screen.fill(BG_COLOR)
px = pygame.transform.scale(px,[rect.width/scale, rect.height/scale])
screen.blit(px, (rect[0]-x,rect[1]-y))
pygame.display.flip()
#px.rect.topleft = pr.rect.topleft[0] - x, defmainLoop(screen, px, filelist):
topleft = bottomright = prior = None
n=0
scale = 1
pos = [0,0]
while n!=1:
for event in pygame.event.get():
if event.type == pygame.MOUSEBUTTONUP:
ifnot topleft:
topleft = [(val+pos[i])*scale for i,val inenumerate(event.pos)]
print"tr: ",topleft
else:
bottomright = [(val+pos[i])*scale for i,val inenumerate(event.pos)]
print"br: ",bottomright
n=1if event.type == pygame.KEYDOWN and event.key == K_a:
pos = [pos[0]-200,pos[1]]
move(pos,scale,px,screen)
if event.type == pygame.KEYDOWN and event.key == K_d:
pos = [pos[0]+200,pos[1]]
move(pos,scale,px,screen)
if event.type == pygame.KEYDOWN and event.key == K_w:
pos = [pos[0],pos[1]-200]
move(pos,scale,px,screen)
if event.type == pygame.KEYDOWN and event.key == K_s:
pos = [pos[0],pos[1]+200]
move(pos,scale,px,screen)
if event.type == pygame.KEYDOWN and event.key == K_RIGHTBRACKET:
scale = scale/1.25
move(pos,scale,px,screen)
if event.type == pygame.KEYDOWN and event.key == K_LEFTBRACKET:
scale = scale*1.25
move(pos,scale,px,screen)
if topleft:
prior = displayRect(screen, px, topleft, prior,pos,scale)
return ( topleft + bottomright )
Use the main function samplebias provided.
Thanks Stack Overflow!
Post a Comment for "Image Cropping Using Python"