Questions tagged [jpeg]

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pset4 - My recover programme compiles but doesn't generate JPEGs as expected

After 12hrs of banging my head against this, and having trawled Stack Exchange, I've decided that it's time to ask for help! Really not sure where I'm going wrong, but suspect it's related to the ...
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1answer
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Retrieving image from SQLite, “Invalid or Unsupported Image Format”

I am getting an Invalid or Unsupported Image Format when I open an image stored and retrieved in SQLite. When I input the convertToBinaryData file into the writeTofile function then the photo is ...
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1answer
64 views

Recover function in pset4

#include <stdio.h> #include <stdlib.h> #include <stdint.h> #include <stdbool.h> /* Open memory card Repeat until end of card: Read 512 bytes of data into buffer If ...
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1answer
76 views

pset4 recover - rick rolled - thinking about this the wrong way?

This is my humble, little code. The comments shows my though process: #include <stdio.h> #include <stdlib.h> int main(int argc, char *argv[]) { if(argc != 2) { printf("...
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1answer
75 views

pset4 recover - doesn`t recover all files

Struggling with recover at this moment. My code creates just 8 pictures out of 50 - from 2nd to 9th. Other jpegs are also made but i am unable to see them due to "Invalid or Unsupported Image Format". ...
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1answer
54 views

recover.c producing random image 🙁

recover.c is always producing this image: Here is my code: #include <stdio.h> #include <stdint.h> typedef enum {false, true} bool; // Bool int main(int argc, char *argv[]) { if (...
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1answer
76 views

Problem Set 4 Recover Issues. I can't figure out why my code doesn't work

I'm busy with problem set 4, and I can't figure out why my code doesn't work. What seems odd is that the first line or two of a new jpeg will seem partially or fully correct, but thereafter the images ...
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1answer
90 views

Segmentation fault on recover pset4

My program compiles, but when I run it I get a segmentation fault and nothing else: ~/workspace/recover/ $ make recover clang -fsanitize=integer -fsanitize=undefined -ggdb3 -O0 -std=c11 -Wall ...
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1answer
62 views

pset4 recover: too many JPEGs found

guys! I was solving recover, but my program finds way too many JPEGs. I believe that this is because of the following lines: // starting bytes of jpeg are in [lower, upper] uint8_t lower[4] = {0xff, ...
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2answers
181 views

PSET4 RECOVER Can't Open JPEGS, I Have Tried Everything Please HELP!

so this is my second time posting about this pset, my code is below. No images will open, with the current code. However when I do get something to open it is just 1 file and it says invalid or ...
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1answer
102 views

No JPEG images printed in recover.c

Since my program compiles fine I am wondering why nothing seems to be outputted from it. I looked at a few threads, but the only close question I found was here Pset4 recover.c compiles, but can'...
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169 views

Why data recovery isn’t an exact science?

I don't understand why it is said in Pset4 that "Odds are, if you find this pattern of four bytes on media known to store photos (e.g., my memory card), they demarcate the start of a JPEG. To be fair, ...
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1answer
126 views

PSET4 Recover Can't Open JPEGs in the IDE

I've recovered all 50 JPEGs and when I download them to my computer and change the name from (for example) 000.jpg%OA I can see the picture correctly. However, in the IDE,if I open the same JPEG I get ...
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1answer
209 views

Having some tough time with pset4 recover.c

I've hit a wall and would appreciate some of you more experienced people to help me through or point me in the right direction. Below is my code, and it generates 27 JPEGs all distorted (numberer 0 - ...
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1answer
142 views

Pset4 - Recover - Not able to find jpegs in card.raw

I'm stuck pretty early on the "Recover" problem. My code doesn't find any JPEGS in the file "card.raw' Here's the relevant bit of my code: #include <stdio.h> #include <stdlib.h> // ...
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1answer
102 views

jpegs do not exists on running recover.c

i have made a program to recover the jpegs i.e. resize.c . The code is : http://pastebin.com/B0XkP9i9 the check 50 results: check50 2016.recover recover.c :) recover.c exists :) recover.c compiles :) ...
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1answer
171 views

recover images from raw file (pset4)

The code manages to identify the signature. However, it seems that it reads incorrect amount of bytes, because it's not identified again. Where did I do wrong? #include <stdio.h> #include <...
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1answer
30 views

pset4/recover: i see files but not all of it and nothing in it

when i run the cod i can see the files but when i open it i can't see any pictures and also not all of the 50 files showed only 21. #include <stdio.h> #include <stdint.h> int main(void) {...
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1answer
154 views

Pset4 recover.c compliles but can't open jpeg

During recover of pset4, I manage to make all the files are made but when opening, an error pops up. /** * recover.c * * Computer Science 50 * Problem Set 4 * * Recovers JPEGs from a forensic ...
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1answer
97 views

Jpeg image files format not supported

I am not able to open the images properly, and here is my code typedef uint8_t BYTE; BYTE buffer[512]; char title[10]; int count =0; FILE* fp = fopen("card.raw","r"); while(!feof(fp)) { fseek(...
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1answer
58 views

Why does my program return a blank jpeg?

I have started recover.c in pset4. I have decided to approach the problem step by step, so first task is recovering the first jpeg. enter code here FILE* file = fopen("card.raw", "r"); ...
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2answers
326 views

PSET4 recover.c not quite working / 98% blank JPEGs

my first post and would appreciate some feedback. I'm taking CS50 online, and the course assumes a lot, especially from someone like me who's only taking up coding again after 15 years (think Basic &...
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1answer
175 views

Need help with “recover”

I can't figure out what's wrong with my code. File names are created successfully but all jpegs just show the corrupt thumbnail. I'm sure it has something to do with finding the start and end of the ...
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1answer
511 views

recover.c cannot detect jpeg signatures?

Trying to get my recover.c to work. My program fread's 512 bytes into a buffer on every iteration of a loop. The buffer is declared as so: unsigned int* cfbfr = malloc(512); Then, at the start of ...